Bind Lookup to Dictionary

• Jul 02, 2024
• 4 minutes to read

A lookup editor can be bound to a Dictionary<TKey,TValue>. The lookup processes keys as values and values as display text. Do not specify the ValueMember and DisplayMember properties.

Note

TKey and TValue should be of the String type or a value type (for example, keys are integers, and values are strings).

C#

using System.Collections.Generic;

// Creates the dictionary.
Dictionary<int, string> products = new Dictionary<int, string>();
products.Add(0, "Product A");
products.Add(1, "Product B");
products.Add(2, "Product C");
products.Add(3, "Product D");
// Binds the lookup to the dictionary.
lookUpEdit1.Properties.DataSource = products;

VB.NET

Imports System.Collections.Generic

' Creates the dictionary.
Private products As New Dictionary(Of Integer, String)()
products.Add(0, "Product A")
products.Add(1, "Product B")
products.Add(2, "Product C")
products.Add(3, "Product D")
' Binds the lookup to the dictionary.
lookUpEdit1.Properties.DataSource = products

The animation below illustrates the result:

Customize Lookup Columns

The lookup’s dropdown displays a column with display values. The lookup hides the column with values. The following code demonstrates how to display the column with values.

C#

using System.Collections.Generic;

public Form1() {
    InitializeComponent();
    Dictionary<int, string> products = new Dictionary<int, string>();
    products.Add(0, "Product A");
    products.Add(1, "Product B");
    products.Add(2, "Product C");
    products.Add(3, "Product D");
    lookUpEdit2.Properties.DataSource = products;
    lookUpEdit2.Properties.ForceInitialize();
    lookUpEdit2.Properties.PopulateColumns();
    lookUpEdit2.Properties.Columns["Key"].Visible = true;
}

VB.NET

Imports System.Collections.Generic

Public Sub New()
    InitializeComponent()
    Dim products As New Dictionary(Of Integer, String)()
    products.Add(0, "Product A")
    products.Add(1, "Product B")
    products.Add(2, "Product C")
    products.Add(3, "Product D")
    lookUpEdit2.Properties.DataSource = products
    lookUpEdit2.Properties.ForceInitialize()
    lookUpEdit2.Properties.PopulateColumns()
    lookUpEdit2.Properties.Columns("Key").Visible = True
End Sub

Example

In this example, the Data Grid embeds a lookup editor to display and edit values in the Category ID column. The lookup is bound to a dictionary with category IDs and names.

Form1.cs

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using DevExpress.XtraEditors.Repository;

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

        private void Form1_Load(object sender, EventArgs e) {
            // Binds the data grid to a data source.
            gridControl1.DataSource = new List<Product> {
                new Product(){ ProductName="Chang", CategoryID =  0  },
                new Product(){ ProductName="Ipoh Coffee", CategoryID =  0  },
                new Product(){ ProductName="Ravioli Angelo", CategoryID = 1  },
                new Product(){ ProductName="Filo Mix", CategoryID = 1  },
                new Product(){ ProductName="Tunnbröd", CategoryID  = 1  },
                new Product(){ ProductName="Konbu", CategoryID  = 2  },
                new Product(){ ProductName="Boston Crab Meat", CategoryID  = 2  }
            };
            // Creates and initializes a dictionary with categories.
            Dictionary<int, string> Categories = new Dictionary<int, string>();
            Categories.Add(0, "Beverages");
            Categories.Add(1, "Grains");
            Categories.Add(2, "Seafood");
            // Creates and initializes a lookup inplace editor (repository item).
            RepositoryItemLookUpEdit riLookUp = new RepositoryItemLookUpEdit();
            riLookUp.DataSource = Categories;
            riLookUp.PopulateColumns();
            riLookUp.Columns["Value"].Caption = "Name";
            // Embeds the lookup editor into the data grid.
            gridControl1.RepositoryItems.Add(riLookUp);
            gridView1.Columns["CategoryID"].ColumnEdit = riLookUp;
        }
    }

    public class Product {
        public int CategoryID { get; set; }
        public string ProductName { get; set; }
    }


}

Form1.vb

Imports DevExpress.XtraEditors.Repository
Imports System
Imports System.Collections.Generic
Imports System.ComponentModel
Imports System.Data
Imports System.Drawing
Imports System.Linq
Imports System.Text
Imports System.Threading.Tasks
Imports System.Windows.Forms

Namespace LookUpEdit_Dictionary
    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

            gridControl1.DataSource = New List(Of Product) From { _
                New Product() With {.ProductName="Chang", .CategoryID = 0}, _
                New Product() With {.ProductName="Ipoh Coffee", .CategoryID = 0}, _
                New Product() With {.ProductName="Ravioli Angelo", .CategoryID = 1}, _
                New Product() With {.ProductName="Filo Mix", .CategoryID = 1}, _
                New Product() With {.ProductName="Tunnbröd", .CategoryID = 1}, _
                New Product() With {.ProductName="Konbu", .CategoryID = 2}, _
                New Product() With {.ProductName="Boston Crab Meat", .CategoryID = 2} _
            }

            Dim Categories As New Dictionary(Of Integer, String)()
            Categories.Add(0, "Beverages")
            Categories.Add(1, "Grains")
            Categories.Add(2, "Seafood")

            Dim riLookUp As New RepositoryItemLookUpEdit()
            riLookUp.DataSource = Categories
            riLookUp.PopulateColumns()
            riLookUp.Columns("Value").Caption = "Name"

            gridControl1.RepositoryItems.Add(riLookUp)
            gridView1.Columns("CategoryID").ColumnEdit = riLookUp
        End Sub
    End Class

    Public Class Product
        Public Property CategoryID() As Integer
        Public Property ProductName() As String
    End Class


End Namespace