Working with Master-Detail Relationships in Code

• Jan 23, 2019
• 19 minutes to read

Data Binding

• Binding to a Regular Database at Runtime
• Binding to Objects with Collection Properties
• Load Details Dynamically by Handling Events
• Load Details Dynamically by Implementing the IRelationList/IRelationListEx Interfaces

Public API

• Acess Views
• Create Multi-Level Detail Relationships in Code
• Access Rows
• Expand and Collapse Rows
• Example 1: Process All Rows
• Example 2: Recursively Expand a Master Row
• Example 3: Expand All Master Rows

Binding to a Regular Database at Runtime

The code below illustrates how to bind a Data Grid to a sample MS Access “NorthWind” database with a master GridView and a detail CardView. You can download and review the complete sample project here.

Tip

This sample data source has a single detail level only. Go to the Create Multi-Level Detail Relationships in Code section for an example on binding to more complex sources that have multiple detail levels.

C#

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Data.OleDb;
using DevExpress.XtraGrid.Views.Card;
using DevExpress.XtraEditors.Repository;

namespace Grid_Runtime_MasterDetail_Mode {
    public partial class Form1 : Form {
        public Form1() {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e) {
            //Define a connection to the database
            OleDbConnection connection = new OleDbConnection(
              "Provider=Microsoft.Jet.OLEDB.4.0;Data Source = ..\\..\\Data\\nwind.mdb");
            //Create data adapters for retrieving data from the tables
            OleDbDataAdapter AdapterCategories = new OleDbDataAdapter(
              "SELECT CategoryID, CategoryName, Picture FROM Categories", connection);
            OleDbDataAdapter AdapterProducts = new OleDbDataAdapter(
              "SELECT CategoryID, ProductID, ProductName, UnitPrice FROM Products", connection);

            DataSet dataSet11 = new DataSet();
            //Create DataTable objects for representing database's tables
            AdapterCategories.Fill(dataSet11, "Categories");
            AdapterProducts.Fill(dataSet11, "Products");

            //Set up a master-detail relationship between the DataTables
            DataColumn keyColumn = dataSet11.Tables["Categories"].Columns["CategoryID"];
            DataColumn foreignKeyColumn = dataSet11.Tables["Products"].Columns["CategoryID"];
            dataSet11.Relations.Add("CategoriesProducts", keyColumn, foreignKeyColumn);

            //Bind the grid control to the data source
            gridControl1.DataSource = dataSet11.Tables["Categories"];
            gridControl1.ForceInitialize();

            //Assign a CardView to the relationship
            CardView cardView1 = new CardView(gridControl1);
            gridControl1.LevelTree.Nodes.Add("CategoriesProducts", cardView1);
            //Specify text to be displayed within detail tabs.
            cardView1.ViewCaption = "Category Products";

            //Hide the CategoryID column for the master View
            gridView1.Columns["CategoryID"].VisibleIndex = -1;

            //Present data in the Picture column as Images
            RepositoryItemPictureEdit riPictureEdit = gridControl1.RepositoryItems.Add("PictureEdit") as RepositoryItemPictureEdit;
            gridView1.Columns["Picture"].ColumnEdit = riPictureEdit;
            //Stretch images within cells.
            riPictureEdit.SizeMode = DevExpress.XtraEditors.Controls.PictureSizeMode.Stretch;
            gridView1.Columns["Picture"].OptionsColumn.FixedWidth = true;
            //Change Picture column's width
            gridView1.Columns["Picture"].Width = 180;

            //Change row height in the master View
            gridView1.RowHeight = 50;

            //Create columns for the detail pattern View
            cardView1.PopulateColumns(dataSet11.Tables["Products"]);
            //Hide the CategoryID column for the detail View
            cardView1.Columns["CategoryID"].VisibleIndex = -1;
            //Format UnitPrice column values as currency
            cardView1.Columns["UnitPrice"].DisplayFormat.FormatType = DevExpress.Utils.FormatType.Numeric;
            cardView1.Columns["UnitPrice"].DisplayFormat.FormatString = "c2";
        }
    }
}

VB.NET

Imports System
Imports System.Collections.Generic
Imports System.ComponentModel
Imports System.Data
Imports System.Drawing
Imports System.Linq
Imports System.Text
Imports System.Windows.Forms
Imports System.Data.OleDb
Imports DevExpress.XtraGrid.Views.Card
Imports DevExpress.XtraEditors.Repository

Namespace Grid_Runtime_MasterDetail_Mode
    Partial Public Class Form1
        Inherits Form

        Public Sub New()
            InitializeComponent()
        End Sub

        Private Sub Form1_Load(ByVal sender As Object, ByVal e As EventArgs) Handles MyBase.Load
            'Define a connection to the database
            Dim connection As New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source = ..\..\Data\nwind.mdb")
            'Create data adapters for retrieving data from the tables
            Dim AdapterCategories As New OleDbDataAdapter("SELECT CategoryID, CategoryName, Picture FROM Categories", connection)
            Dim AdapterProducts As New OleDbDataAdapter("SELECT CategoryID, ProductID, ProductName, UnitPrice FROM Products", connection)

            Dim dataSet11 As New DataSet()
            'Create DataTable objects for representing database's tables
            AdapterCategories.Fill(dataSet11, "Categories")
            AdapterProducts.Fill(dataSet11, "Products")

            'Set up a master-detail relationship between the DataTables
            Dim keyColumn As DataColumn = dataSet11.Tables("Categories").Columns("CategoryID")
            Dim foreignKeyColumn As DataColumn = dataSet11.Tables("Products").Columns("CategoryID")
            dataSet11.Relations.Add("CategoriesProducts", keyColumn, foreignKeyColumn)

            'Bind the grid control to the data source
            gridControl1.DataSource = dataSet11.Tables("Categories")
            gridControl1.ForceInitialize()

            'Assign a CardView to the relationship
            Dim cardView1 As New CardView(gridControl1)
            gridControl1.LevelTree.Nodes.Add("CategoriesProducts", cardView1)
            'Specify text to be displayed within detail tabs.
            cardView1.ViewCaption = "Category Products"

            'Hide the CategoryID column for the master View
            gridView1.Columns("CategoryID").VisibleIndex = -1

            'Present data in the Picture column as Images
            Dim riPictureEdit As RepositoryItemPictureEdit = TryCast(gridControl1.RepositoryItems.Add("PictureEdit"), RepositoryItemPictureEdit)
            gridView1.Columns("Picture").ColumnEdit = riPictureEdit
            'Stretch images within cells.
            riPictureEdit.SizeMode = DevExpress.XtraEditors.Controls.PictureSizeMode.Stretch
            gridView1.Columns("Picture").OptionsColumn.FixedWidth = True
            'Change Picture column's width
            gridView1.Columns("Picture").Width = 180

            'Change row height in the master View
            gridView1.RowHeight = 50

            'Create columns for the detail pattern View
            cardView1.PopulateColumns(dataSet11.Tables("Products"))
            'Hide the CategoryID column for the detail View
            cardView1.Columns("CategoryID").VisibleIndex = -1
            'Format UnitPrice column values as currency
            cardView1.Columns("UnitPrice").DisplayFormat.FormatType = DevExpress.Utils.FormatType.Numeric
            cardView1.Columns("UnitPrice").DisplayFormat.FormatString = "c2"
        End Sub
    End Class
End Namespace

Binding to Objects with Collection Properties

If the Data Grid is bound to a data source where records provide property (or properties) of the IList type (e.g., ArrayList or List<T>), these collection properties are treated as detail Views unless the GridOptionsDetail.EnableMasterViewMode is explicitly disabled.

Properties of the IList<T>, ICollection<T> and IEnumerable types are not recognized as collection properties by default. To treat them as collection properties, enable the BaseView.DataController.AllowIEnumerableDetails option prior to binding the Data Grid to a data source.

In this example, the Data Grid is bound to an ArrayList object “NestedRecords”. Data source entities are objects of the “NestedRecord” class, which provides two properties: a string “Name” and an ArrayList “ChildList”. Such a data source is automatically recognized by the Data Grid as a master-detail source.

C#

gridControl1.DataSource = new NestedRecords();
//... 
public class NestedRecords : ArrayList {
    public NestedRecords() {
        Add(new NestedRecord("Customers", new ChildRecordsCustomers()));
        Add(new NestedRecord("Products", new ChildRecordsProducts()));
        Add(new NestedRecord("Shippers", new ChildRecordsShippers()));
    }
    public virtual new NestedRecord this[int index] {
        get { return (NestedRecord)(base[index]); }
    }
}

//Products
public class ChildRecordsProducts : ArrayList
{
    public ChildRecordsProducts()
    {
        for (int i = 0; i < 10; i++)
            Add(new Product() { Price = i, Name = "Product" + i });
    }
}
public class Product
{
    public string Name { get; set; }
    public double Price { get; set; }
}

//Customers
//. . .

//Shippers
//. . .

//Nested Records
public class NestedRecord {
    private string fName;
    ArrayList fChildList = null;

    public NestedRecord(string name, ArrayList childList) {
        this.fName = name;
        this.fChildList = childList;
    }

    public string Name {
        get { return fName; }
        set { fName = value; }
    }

    public ArrayList ChildList {
        get { return fChildList; }
        set { fChildList = value; }
    }
}

VB.NET

gridControl1.DataSource = New NestedRecords()
'... 
public class NestedRecords : ArrayList
    public NestedRecords()
        Add(New NestedRecord("Customers", New ChildRecordsCustomers()))
        Add(New NestedRecord("Products", New ChildRecordsProducts()))
        Add(New NestedRecord("Shippers", New ChildRecordsShippers()))
    public virtual New NestedRecord Me(Integer index)
        Get
            Return CType(MyBase.Item(index), NestedRecord)
        End Get

'Products
public class ChildRecordsProducts : ArrayList
    public ChildRecordsProducts()
        For i As Integer = 0 To 9
            Add(New Product() With {.Price = i, .Name = "Product" & i})
        Next i
public class Product
    public String Name {get;set;}
    public Double Price {get;set;}

'Customers
'. . .

'Shippers
'. . .

'Nested Records
public class NestedRecord
    private String fName
    Dim fChildList As ArrayList = Nothing

    public NestedRecord(String name, ArrayList childList)
        Me.fName = name
        Me.fChildList = childList

    public String Name
        Get
            Return fName
        End Get
        Set
            fName = value
        End Set

    public ArrayList ChildList
        Get
            Return fChildList
        End Get
        Set
            fChildList = value
        End Set

Load Details Dynamically by Handling Events

To load details dynamically, rather from a bound source, handle the following events.

Primary Events

• GridView.MasterRowGetRelationCount

  Fires repeatedly for every row and allows you to specify several details for this row. To identify a row for which the event is raised, read the event’s RowHandle parameter. Then, set the RelationCount parameter accordingly to the desired number of detail tables. Occasionally, the Data Grid fires this event with a RowHandle equal to the GridControl.InvalidRowHandle constant. This is a service event that allows you to display or hide all master row expand/collapse buttons. Set the RelationCount to any positive number to show these buttons.

  C#

  
  gridView.MasterRowGetRelationCount += (s, e) => {
      // set to any positive value to display expand/collapse buttons for master rows
      if (e.RowHandle == DevExpress.XtraGrid.GridControl.InvalidRowHandle) e.RelationCount = 100;
      // even master rows have two details, odd master rows have none
      else if (e.RowHandle % 2 != 0) e.RelationCount = 2;
  };
  

  VB.NET

  
  AddHandler gridView.MasterRowGetRelationCount, Sub(s, e)
      ' set to any positive value to display expand/collapse buttons for master rows
      If e.RowHandle = DevExpress.XtraGrid.GridControl.InvalidRowHandle Then
        e.RelationCount = 100
      ' even master row have two details, odd master rows have none
      ElseIf e.RowHandle Mod 2 <> 0 Then
        e.RelationCount = 2
      End If
  End Sub
  

• GridView.MasterRowEmpty

  Fires for each row that has been marked by the GridView.MasterRowGetRelationCount event as a row that has details. For each of these non-empty rows, the GridView.MasterRowEmpty event fires as many times as the MasterRowGetRelationCount event’s RelationCount parameter is. To retrieve the number of the currently processed detail, read the RelationIndex parameter, then set the IsEmpty parameter to a required boolean value. Empty details are not shown.

  C#

  
  // all master rows have 5 detail
  gridView.MasterRowGetRelationCount += (s, e) => {
      e.RelationCount = 5;
  };
  
  // details with even indexes are not empty, details with odd indexes are hidden
  gridView.MasterRowEmpty += (s, e) => {
      if (e.RelationIndex%2!=0) { e.IsEmpty = true; }
      else e.IsEmpty = false;
  };
  

  VB.NET

  
  ' all master rows have 5 detail
  AddHandler gridView.MasterRowGetRelationCount, Sub(s, e) e.RelationCount = 5
  
  ' details with even indexes are not empty, details with odd indexes are hidden
  AddHandler gridView.MasterRowEmpty, Sub(s, e)
      If e.RelationIndex Mod 2<>0 Then
        e.IsEmpty = True
      Else
        e.IsEmpty = False
      End If
  End Sub
  

• GridView.MasterRowGetRelationName

  This parameter allows you to set the RelationName parameter for each detail. This name is used to retrieve the required pattern View from the GridControl.LevelTree tree. At the same time, the RelationName specifies a default caption for the detail tab.

  C#

  
  gridView1.MasterRowGetRelationName += (s, e) => {
      switch (e.RelationIndex) {
          case 0:
              e.RelationName = "Order Detail";
              break;
          case 1:
              e.RelationName = "Customer Details";
              break;
          case 2:
              e.RelationName = "Employee Details";
              break;
      }
  };
  

  VB.NET

  
  AddHandler gridView1.MasterRowGetRelationName, Sub(s, e)
      Select Case e.RelationIndex
          Case 0
              e.RelationName = "Order Detail"
          Case 1
              e.RelationName = "Customer Details"
          Case 2
              e.RelationName = "Employee Details"
      End Select
  End Sub
  

• GridView.MasterRowGetChildList

  When the required pattern View is obtained, the Data Grid creates its clone View to display detail data. Set the event’s ChildList parameter to provide data to these clones.

  C#

  
  gridView.MasterRowGetChildList += (s, e) => {
      // details with even indexes receive data from one sample source
      if (e.RelationIndex%2 != 0) e.ChildList = SampleData1.GetData().ToList();
      // details with odd indexes receive data from another one
      else e.ChildList = SampleData2.GetData().ToList();
  };
  

  VB.NET

  
  AddHandler gridView.MasterRowGetChildList, Sub(s, e)
      ' details with even indexes receive data from one sample source
      If e.RelationIndex Mod 2 <> 0 Then
        e.ChildList = SampleData1.GetData().ToList()
      ' details with odd indexes receive data from another one
      Else
        e.ChildList = SampleData2.GetData().ToList()
      End If
  End Sub
  

Optional Events

• GridView.MasterRowGetRelationDisplayCaption

  Handle this event if you want detail tabs to have different captions than detail names, set on the GridView.MasterRowGetRelationName event.

• GridView.MasterRowGetLevelDefaultView

  This event allows you to explicitly provide a pattern View for a specific detail. Generally, this is required only when the View does not belong to the GridControl.LevelTree tree. Otherwise, pattern Views are provided indirectly on the GridView.MasterRowGetRelationName event.

• GridView.MasterRowExpanding

  Handle this event to prevent specific master rows from expanding.

Demo: Master-detail mode using events

Load Details Dynamically by Implementing the IRelationList/IRelationListEx Interfaces

As an alternative to handling View events, you can also implement the IRelationList/IRelationListEx interface for your runtime created data or a .NET data structure (e.g., a System.Data.DataView object). The IRelationList interface provides the following members.

• IRelationList.RelationCount

  Returns the number of master-detail relationships for master rows. If set to zero, the master-detail mode is disabled.

• IRelationList.IsMasterRowEmpty

  Specifies whether or not a specific detail has data.

• IRelationList.GetRelationName

  Specifies a relation name, with which the required pattern View is retrieved from the GridControl.LevelTree tree. This same name is displayed by a detail tab at runtime.

• IRelationList.GetDetailList

  Must return data for a specific clone View.

The IRelationListEx interface extends the IRelationList with two additional methods. These allow you to provide different numbers of master-detail relationships for master rows and customize captions for relationships.

• IRelationListEx.GetRelationCount

  Returns the number of relationships for this specific master row.

• IRelationListEx.GetRelationDisplayName

  Returns the relationship caption, displayed in a detail tab.

The code below demonstrates the IRelationList interface implemented for the NWTables class, which serves as a data source in the Master-Detail (unbound) demo.

C#

public class NWTables : ArrayList, DevExpress.Data.IRelationList {
    private DataSet dataSet;
    public NWTables(DataSet ds) {
        Add(new NWTable(Properties.Resources.SuppliersTable, "Suppliers"));
        Add(new NWTable(Properties.Resources.CategoriesTable, "Categories"));
        Add(new NWTable(Properties.Resources.EmployeesTable, "Employees"));
        Add(new NWTable(Properties.Resources.ShippersTable, "Shippers"));
        Add(new NWTable(Properties.Resources.CustomersTable, "Customers"));
        Add(new NWTable(Properties.Resources.OrdersTable, "Orders500"));
        dataSet = ds;
    }
    //IRelationList
    string IRelationList.GetRelationName(int index, int relationIndex) {
        if(index >= 0 && index < this.Count)
            return this[index].RelationName;
        return "";
    }

    int IRelationList.RelationCount {
        get { return dataSet.Tables.Count > 0 ? 1 : 0; }
    }

    IList IRelationList.GetDetailList(int index, int relationIndex) {
        if(dataSet.Tables.Count > 0) 
            return dataSet.Tables[((NWTable)this[index]).TableName()].DefaultView;
        return null;
    }

    bool IRelationList.IsMasterRowEmpty(int index, int relationIndex) {
        return false;
    }
    //IRelationList

    public virtual new NWTable this[int index] {
        get {return (NWTable)(base[index]);}
    }
}

VB.NET

Public Class NWTables
  Inherits ArrayList
  Implements DevExpress.Data.IRelationList

  Private dataSet As DataSet
  Public Sub New(ByVal ds As DataSet)
    Add(New NWTable(My.Resources.SuppliersTable, "Suppliers"))
    Add(New NWTable(My.Resources.CategoriesTable, "Categories"))
    Add(New NWTable(My.Resources.EmployeesTable, "Employees"))
    Add(New NWTable(My.Resources.ShippersTable, "Shippers"))
    Add(New NWTable(My.Resources.CustomersTable, "Customers"))
        Add(New NWTable(My.Resources.OrdersTable, "Orders500"))
    dataSet = ds
  End Sub
  'IRelationList
  Private Function IRelationList_GetRelationName(ByVal index As Integer, ByVal relationIndex As Integer) As String Implements IRelationList.GetRelationName
    If index >= 0 AndAlso index < Me.Count Then
      Return Me(index).RelationName
    End If
    Return ""
  End Function

  Private ReadOnly Property IRelationList_RelationCount() As Integer Implements IRelationList.RelationCount
    Get
      Return If(dataSet.Tables.Count > 0, 1, 0)
    End Get
  End Property

  Private Function IRelationList_GetDetailList(ByVal index As Integer, ByVal relationIndex As Integer) As IList Implements IRelationList.GetDetailList
    If dataSet.Tables.Count > 0 Then
      Return dataSet.Tables(CType(Me(index), NWTable).TableName()).DefaultView
    End If
    Return Nothing
  End Function

  Private Function IRelationList_IsMasterRowEmpty(ByVal index As Integer, ByVal relationIndex As Integer) As Boolean Implements IRelationList.IsMasterRowEmpty
    Return False
  End Function
  'IRelationList

  Default Public Overridable Shadows ReadOnly Property Item(ByVal index As Integer) As NWTable
    Get
      Return DirectCast(MyBase.Item(index), NWTable)
    End Get
  End Property
End Class

Demo: Master-Detail (unbound)

Access Views

GridControl.MainView

Retrieves the top-level master View.

GridView.GetDetailView

Returns a detail clone View for a specific master row. The example below illustrates how to retrieve the focused cell value for a clone View.

C#

using DevExpress.XtraGrid.Views.Grid;

gridView1.MasterRowExpanded += GridView1_MasterRowExpanded;
gridView1.OptionsBehavior.Editable = gridView2.OptionsBehavior.Editable = false;

private void GridView1_MasterRowExpanded(object sender, DevExpress.XtraGrid.Views.Grid.CustomMasterRowEventArgs e) {
    GridView master = sender as GridView;
    GridView detail = master.GetDetailView(e.RowHandle, e.RelationIndex) as GridView;
    detail.Click += new EventHandler(detail_Click);
}

void detail_Click(object sender, EventArgs e) {
    GridView gridView = sender as GridView;
    var value = gridView.GetRowCellValue(gridView.FocusedRowHandle, gridView.FocusedColumn);
    MessageBox.Show("Cell value: " + value.ToString(), "Message");
}

VB.NET

Imports DevExpress.XtraGrid.Views.Grid

Private gridView1.MasterRowExpanded += AddressOf GridView1_MasterRowExpanded
gridView2.OptionsBehavior.Editable = False
gridView1.OptionsBehavior.Editable = gridView2.OptionsBehavior.Editable

private void GridView1_MasterRowExpanded(Object sender, DevExpress.XtraGrid.Views.Grid.CustomMasterRowEventArgs e)
    Dim master As GridView = TryCast(sender, GridView)
    Dim detail As GridView = TryCast(master.GetDetailView(e.RowHandle, e.RelationIndex), GridView)
    AddHandler detail.Click, AddressOf detail_Click

void detail_Click(Object sender, EventArgs e)
    Dim gridView As GridView = TryCast(sender, GridView)
    Dim value = gridView.GetRowCellValue(gridView.FocusedRowHandle, gridView.FocusedColumn)
    MessageBox.Show("Cell value: " & value.ToString(), "Message")

BaseView.ParentView

For clone Views, this property returns a master View. For pattern and main Views, returns null (Nothing in Visual Basic).

GridView.GetVisibleDetailView

Returns a currently visible detail clone for a specific master row.

GridControl.Views

Provides access to master and clone Views that are currently visible. Detail clones are dynamically added to or removed from this collection as details expand or collapse.

GridControl.LevelTree

Provides access to a hierarchical structure that associates pattern Views with master-detail relationships. Hierarchy nodes are represented by the GridLevelNode class objects. The following sample illustrates how to replace a View for a master-detail “Orders” relationship with a new banded View.

C#

using DevExpress.XtraGrid;
using DevExpress.XtraGrid.Views.Base;
using DevExpress.XtraGrid.Views.Grid;
using DevExpress.XtraGrid.Views.BandedGrid;

// Collapse all the details opened for the master rows in the main view.
(gridControl1.MainView as GridView).CollapseAllDetails();

// Get the node at the first nesting level that stores a view for the "Orders" relation.
GridLevelNode node = gridControl1.LevelTree.Nodes["Orders"];
if(node == null) return;
// The old view which represents the "Orders" relation.
BaseView oldView = node.LevelTemplate;         
// Dispose of this view.
oldView.Dispose();

// Create a new view.
BandedGridView bandedView = new BandedGridView(gridControl1);            
// Associate this view with the "Orders" relation.
node.LevelTemplate = bandedView;

// Customize the new view.
GridBand band = bandedView.Bands.Add("Orders");
BandedGridColumn column = (BandedGridColumn)bandedView.Columns.Add("ID");
column.OwnerBand = band;
column.Visible = true;

column = (BandedGridColumn)bandedView.Columns.AddField("ProductID");
column.OwnerBand = band;
column.Visible = true;

VB.NET

Imports DevExpress.XtraGrid
Imports DevExpress.XtraGrid.Views.Base
Imports DevExpress.XtraGrid.Views.Grid
Imports DevExpress.XtraGrid.Views.BandedGrid

' Collapse all the details opened for the master rows in the main view.
CType(GridControl1.MainView, GridView).CollapseAllDetails()

' Get the node at the first nesting level that stores a view for the "Orders" relation.
Dim node As GridLevelNode = GridControl1.LevelTree.Nodes("Orders")
If node Is Nothing Then Return
' The old view which represents the "Orders" relation.
Dim oldView As BaseView = node.LevelTemplate
' Dispose of this view.
oldView.Dispose()

' Create a new view.
Dim bandedView As BandedGridView = New BandedGridView(GridControl1)
' Associate this view with the "Orders" relation.
node.LevelTemplate = bandedView

' Customize the new view.
Dim band As GridBand = bandedView.Bands.Add("Orders")
Dim column As BandedGridColumn = bandedView.Columns.Add("ID")
column.OwnerBand = band
column.Visible = True

column = bandedView.Columns.AddField("ProductID")
column.OwnerBand = band
column.Visible = True

Create Multi-Level Detail Relationships in Code

To add multi-level details, you need to create a template View for each level. Also, create a GridLevelNode object for each existing child View. The topmost detail View’s node goes into the GridControl.LevelTree collection, further nodes must be added into the GridLevelNode.Nodes collections of their parent nodes.

C#

GridControl gridControl = new GridControl();
GridView view1 = new DevExpress.XtraGrid.Views.Grid.GridView();
GridView view2 = new DevExpress.XtraGrid.Views.Grid.GridView();
GridView view3 = new DevExpress.XtraGrid.Views.Grid.GridView();

//Root master-detail relation
DevExpress.XtraGrid.GridLevelNode myGridLevelNode1 = new DevExpress.XtraGrid.GridLevelNode();
myGridLevelNode1.LevelTemplate = view2;
myGridLevelNode1.RelationName = "Relation1";

//Secondary master-detail relation
DevExpress.XtraGrid.GridLevelNode myGridLevelNode2 = new DevExpress.XtraGrid.GridLevelNode();
myGridLevelNode2.LevelTemplate = view3;
myGridLevelNode2.RelationName = "Relation2";

//add Node2 to Node1's collection of child nodes
myGridLevelNode1.Nodes.AddRange(new DevExpress.XtraGrid.GridLevelNode[] {
myGridLevelNode2});
//add Node1 to the grid's node collection
gridControl.LevelTree.Nodes.AddRange(new DevExpress.XtraGrid.GridLevelNode[] {
myGridLevelNode1});

gridControl.Dock = System.Windows.Forms.DockStyle.Right;
gridControl.MainView = view1;
gridControl.Name = "gridControl1";
gridControl.ViewCollection.AddRange(new DevExpress.XtraGrid.Views.Base.BaseView[] { view1, view2, view3 });
this.Controls.Add(gridControl);

VB.NET

Dim gridControl As New GridControl()
Dim view1 As GridView = New DevExpress.XtraGrid.Views.Grid.GridView()
Dim view2 As GridView = New DevExpress.XtraGrid.Views.Grid.GridView()
Dim view3 As GridView = New DevExpress.XtraGrid.Views.Grid.GridView()

'Root master-detail relation
Dim myGridLevelNode1 As New DevExpress.XtraGrid.GridLevelNode()
myGridLevelNode1.LevelTemplate = view2
myGridLevelNode1.RelationName = "Relation1"

'Secondary master-detail relation
Dim myGridLevelNode2 As New DevExpress.XtraGrid.GridLevelNode()
myGridLevelNode2.LevelTemplate = view3
myGridLevelNode2.RelationName = "Relation2"

'add Node2 to Node1's collection of child nodes
myGridLevelNode1.Nodes.AddRange(New DevExpress.XtraGrid.GridLevelNode() { myGridLevelNode2})
'add Node1 to the grid's node collection
gridControl.LevelTree.Nodes.AddRange(New DevExpress.XtraGrid.GridLevelNode() { myGridLevelNode1})

gridControl.Dock = System.Windows.Forms.DockStyle.Right
gridControl.MainView = view1
gridControl.Name = "gridControl1"
gridControl.ViewCollection.AddRange(New DevExpress.XtraGrid.Views.Base.BaseView() { view1, view2, view3 })
Me.Controls.Add(gridControl)

Access Rows

BaseView.SourceRow, BaseView.SourceRowHandle

Returns a row (or its handle) that owns this clone View.

Expand and Collapse Rows

GridView.ExpandMasterRow, GridView.CollapseMasterRow

Expands or collapses the specific master row.

GridView.GetMasterRowExpanded, GridView.SetMasterRowExpanded

Call these methods to identify whether or not a particular master row is collapsed and expand it manually.

GridView.GetMasterRowExpandedEx, GridView.SetMasterRowExpandedEx

Call these methods to identify whether or not a specific clone of a master row is visible, and if not, show it.

GridView.CollapseAllDetails

Collapses all master rows for a specific View.

Example 1: Process All Rows

The following example iterates through rows of all master and clone Views. To access clones, master rows must be expanded. After all rows have been processed, their original expand/collapse state is restored.

C#

using DevExpress.XtraGrid.Views.Grid;
using DevExpress.XtraGrid.Views.Base;

public void NavigateDetails(ColumnView inspectedView) {
    if(inspectedView == null) return;
    // Prevent excessive visual updates. 
    inspectedView.BeginUpdate();
    try {
        GridView gridView = inspectedView as GridView;
        // Get the number of data rows in the View. 
        int dataRowCount;
        if(gridView == null)
            dataRowCount = inspectedView.RowCount;
        else 
            dataRowCount = gridView.DataRowCount;
        // Traverse View's rows. 
        for(int rowHandle = 0; rowHandle < dataRowCount; rowHandle++) {
            // Place your code here to process the current row. 
            // ...                     
            if(gridView != null) {                        
                // Get the number of master-detail relationships for the current row. 
                int relationCount = gridView.GetRelationCount(rowHandle);                    
                // Iterate through master-detail relationships. 
                for(int relationIndex = 0; relationIndex < relationCount; relationIndex++) {
                    // Store expansion status of the corresponding detail View. 
                    bool wasExpanded = gridView.GetMasterRowExpandedEx(rowHandle, relationIndex);
                    // Expand the detail View. 
                    if(!wasExpanded)
                        gridView.SetMasterRowExpandedEx(rowHandle, relationIndex, true);
                    // Navigate the detail View. 
                    NavigateDetails((ColumnView)gridView.GetDetailView(rowHandle, relationIndex));
                    // Restore the row's expansion status. 
                    gridView.SetMasterRowExpandedEx(rowHandle, relationIndex, wasExpanded);
                }
            }
        }
    }
    finally {
        // Enable visual updates. 
        inspectedView.EndUpdate();
    }
}

VB.NET

Imports DevExpress.XtraGrid.Views.Grid
Imports DevExpress.XtraGrid.Views.Base

Public Sub NavigateDetails(ByVal inspectedView As ColumnView)
    If inspectedView Is Nothing Then Return 
    ' Prevent excessive visual updates. 
    inspectedView.BeginUpdate()
    Try 
        Dim gridView As GridView = Nothing 
        If TypeOf inspectedView Is GridView Then gridView = inspectedView
        ' Get the number of data rows in the View. 
        Dim dataRowCount As Integer 
        If gridView Is Nothing Then 
            dataRowCount = inspectedView.RowCount
        Else 
            dataRowCount = gridView.DataRowCount
        End If 
        ' Traverse View's rows. 
        Dim rowHandle As Integer 
        For rowHandle = 0 To dataRowCount - 1
            ' Place your code here to process the current row. 
            ' ... 
            Try 
                inspectedView.SetRowCellValue(rowHandle, inspectedView.Columns(0), rowHandle)
            Catch ex As Exception

            End Try 
            If Not gridView Is Nothing Then 
                ' Get the number of master-detail relationships for the current row. 
                Dim relationCount As Integer = gridView.GetRelationCount(rowHandle)
                ' Iterate through master-detail relationships. 
                Dim relationIndex As Integer 
                For relationIndex = 0 To relationCount - 1
                    ' Store expansion status of the corresponding detail View. 
                    Dim wasExpanded As Boolean = _
                      gridView.GetMasterRowExpandedEx(rowHandle, relationIndex)
                    ' Expand the detail View. 
                    If Not wasExpanded Then gridView.SetMasterRowExpandedEx( _
                      rowHandle, relationIndex, True)
                    ' Navigate the detail View. 
                    NavigateDetails(gridView.GetDetailView(rowHandle, relationIndex))
                    ' Restore the row's expansion status. 
                    gridView.SetMasterRowExpandedEx(rowHandle, relationIndex, wasExpanded)
                Next 
            End If 
        Next 

    Finally 
        ' Enable visual updates. 
        inspectedView.EndUpdate()
    End Try 
End Sub 

Example 2: Recursively Expand a Master Row

This method expands a row and scans for its detail Views. If there are any, they are expanded as well. The process repeats until all underlying details are expanded.

C#

using DevExpress.XtraGrid.Views.Grid;

// expand all nested details for the focused row
private void barButtonItem1_ItemClick(object sender, DevExpress.XtraBars.ItemClickEventArgs e) {
    RecursiveExpand(gridView1, gridView1.FocusedRowHandle);
}

// custom method for expanding nested details
public void RecursiveExpand(GridView masterView, int masterRowHandle) {
    try {
        var relationCount = masterView.GetRelationCount(masterRowHandle);
        for (var index = relationCount - 1; index >= 0; index--) {
            masterView.ExpandMasterRow(masterRowHandle, index);
            var childView = masterView.GetDetailView(masterRowHandle, index) as GridView;
            if (childView != null) {
                var childRowCount = childView.DataRowCount;
                for (var handle = 0; handle < childRowCount; handle++)
                    RecursiveExpand(childView, handle);
            }
        }
    }
    catch (Exception ex) { }
    finally { }
}

VB.NET

Imports DevExpress.XtraGrid.Views.Grid
Imports DevExpress.XtraGrid.Views.Base

' expand all nested details for the focused row
Private Sub barButtonItem1_ItemClick(ByVal sender As Object, ByVal e As DevExpress.XtraBars.ItemClickEventArgs)
    RecursiveExpand(gridView1, gridView1.FocusedRowHandle)
End Sub

' custom method for expanding nested details
Public Sub RecursiveExpand(ByVal masterView As GridView, ByVal masterRowHandle As Integer)
    Try
        Dim relationCount = masterView.GetRelationCount(masterRowHandle)
        For index = relationCount - 1 To 0 Step -1
            masterView.ExpandMasterRow(masterRowHandle, index)
            Dim childView = TryCast(masterView.GetDetailView(masterRowHandle, index), GridView)
            If childView IsNot Nothing Then
                Dim childRowCount = childView.DataRowCount
                For handle = 0 To childRowCount - 1
                    RecursiveExpand(childView, handle)
                Next handle
            End If
        Next index
    Catch ex As Exception
    Finally
    End Try
End Sub

Example 3: Expand All Master Rows

The Data Grid does not provide a method to expand all master rows for a single View. You can, however, implement such a method yourself.

C#

using DevExpress.XtraGrid.Views.Grid;
//... 
public void ExpandAllRows(GridView View) {
    View.BeginUpdate();
    try {
        int dataRowCount = View.DataRowCount;
        for(int rHandle = 0; rHandle < dataRowCount; rHandle ++)
            View.SetMasterRowExpanded(rHandle, true);
    }
    finally {
        View.EndUpdate();
    }
}

VB.NET

Imports DevExpress.XtraGrid.Views.Grid
'... 
Public Sub ExpandAllRows(ByVal View As GridView)
    View.BeginUpdate()
    Try 
        Dim dataRowCount As Integer = View.DataRowCount
        Dim rHandle As Integer 
        For rHandle = 0 To dataRowCount - 1
            View.SetMasterRowExpanded(rHandle, True)
        Next 
    Finally 
        View.EndUpdate()
    End Try 
End Sub