GridColumn.UnboundDataType Property

Allows you to make the column unbound, and specify the type of data it stores.

Namespace: DevExpress.XtraGrid.Columns

Assembly: DevExpress.XtraGrid.v24.1.dll

NuGet Packages: DevExpress.Win.Grid, DevExpress.Win.Navigation

Declaration

C#

[DXCategory("Data")]
public Type UnboundDataType { get; set; }

VB.NET

<DXCategory("Data")>
Public Property UnboundDataType As Type

Property Value

Type	Description
Type	The type of data to store in the unbound column.

Remarks

If the UnboundDataType property is not set to a valid data type (the property’s default value is System.Void), the current column is considered bound to a data source field (GridColumn.FieldName).

To switch a column to unbound mode, do the following:

• Set the UnboundDataType property to the type of values this column should store.
• Assign a unique field name to the GridColumn.FieldName property. The field name must not match the field name of another column nor the name of a data source field.
• Use one of the following techniques to populate the unbound column with data:
  • Specify an expression (GridColumn.UnboundExpression) to calculate unbound values. Users cannot edit column cells if you specify an expression.
  • Handle the ColumnView.CustomUnboundColumnData event to specify unbound column values. Columns populated in this way remain editable.

If you set a column’s UnboundDataType property to typeof(<object>) (GetType(<object>) in Visual Basic), this column supports sort, group, and filter operations only if the <object> class implements the IComparable interface.

See the following help topic for more information: Unbound Columns.

Example

In the following example, it is assumed that the Grid Control is bound to a table that contains the “Quantity”, “UnitPrice”, and “Discount” columns. The code below adds an unbound column that calculates the total order amount according to the following expression: Quantity * UnitPrice * (1-Discount).

C#

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

private void Form1_Load(object sender, EventArgs e) {
    // ...
    gridControl1.ForceInitialize();

    // Create an unbound column.
    GridColumn unboundColumn = gridView1.Columns.AddField("Total");
    unboundColumn.VisibleIndex = gridView1.Columns.Count;
    unboundColumn.UnboundDataType = typeof(decimal);
    // Disable column edit operations.
    unboundColumn.OptionsColumn.AllowEdit = false;
    // Specify format settings.
    unboundColumn.DisplayFormat.FormatType = DevExpress.Utils.FormatType.Numeric;
    unboundColumn.DisplayFormat.FormatString = "c";
    // Customize appearance settings.
    unboundColumn.AppearanceCell.BackColor = Color.FromArgb(179, 226, 221);
}

// Return the total amount for a specific row.
decimal getTotalValue(GridView view, int listSourceRowIndex) {
    decimal unitPrice = Convert.ToDecimal(view.GetListSourceRowCellValue(listSourceRowIndex, "UnitPrice"));
    decimal quantity = Convert.ToDecimal(view.GetListSourceRowCellValue(listSourceRowIndex, "Quantity"));
    decimal discount = Convert.ToDecimal(view.GetListSourceRowCellValue(listSourceRowIndex, "Discount"));
    return unitPrice * quantity * (1 - discount);
}

// Specify data for the Total column.
private void gridView1_CustomUnboundColumnData(object sender, CustomColumnDataEventArgs e) {
   GridView view = sender as GridView;
   if (e.Column.FieldName == "Total" && e.IsGetData) e.Value = 
     getTotalValue(view, e.ListSourceRowIndex);
}

VB.NET

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

Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
    ' ...
    GridControl1.ForceInitialize()

    ' Create an unbound column.
    Dim unboundColumn As GridColumn = GridView1.Columns.AddField("Total")
    unboundColumn.VisibleIndex = GridView1.Columns.Count
    unboundColumn.UnboundDataType = GetType(Decimal)
    ' Disable column edit operations.
    unboundColumn.OptionsColumn.AllowEdit = False
    ' Specify format settings.
    unboundColumn.DisplayFormat.FormatType = DevExpress.Utils.FormatType.Numeric
    unboundColumn.DisplayFormat.FormatString = "c"
    ' Customize appearance settings.
    unboundColumn.AppearanceCell.BackColor = Color.FromArgb(179, 226, 221)

End Sub

' Return the total amount for a specific row.
Private Function getTotalValue(view As GridView, listSourceRowIndex As Integer) As Decimal
    Dim unitPrice As Decimal = Convert.ToDecimal(view.GetListSourceRowCellValue(listSourceRowIndex, "UnitPrice"))
    Dim quantity As Decimal = Convert.ToDecimal(view.GetListSourceRowCellValue(listSourceRowIndex, "Quantity"))
    Dim discount As Decimal = Convert.ToDecimal(view.GetListSourceRowCellValue(listSourceRowIndex, "Discount"))
    Return unitPrice * quantity * (1 - discount)
End Function

' Specify data for the Total column.
Private Sub GridView1_CustomUnboundColumnData(ByVal sender As Object,
ByVal e As CustomColumnDataEventArgs) Handles GridView1.CustomUnboundColumnData
    Dim view As GridView = TryCast(sender, GridView)
    If e.Column.FieldName = "Total" AndAlso e.IsGetData Then
        e.Value = getTotalValue(view, e.ListSourceRowIndex)
    End If
End Sub