ColumnView.CustomColumnDisplayText Event

Allows you to replace cell display texts (for cells with textbox-based editors), group row texts, and filter menu item captions.

Namespace: DevExpress.XtraGrid.Views.Base

Assembly: DevExpress.XtraGrid.v20.1.dll

Declaration

[DXCategory("Data")]
public event CustomColumnDisplayTextEventHandler CustomColumnDisplayText
<DXCategory("Data")>
Public Event CustomColumnDisplayText As CustomColumnDisplayTextEventHandler

Event Data

The CustomColumnDisplayText event's data class is CustomColumnDisplayTextEventArgs. The following properties provide information specific to this event:

Property Description
Column Gets the column that contains the cell currently being processed.
DisplayText Gets or sets the display text for the cell currently being processed.
GroupRowHandle Gets the handle of the currently processed group row. Returns the GridControl.InvalidRowHandle value if the CustomColumnDisplayText event is not called for a group row.
IsForGroupRow Returns whether the CustomColumnDisplayText event is called to get the display text of a column value displayed within a group row.
ListSourceRowIndex Gets the index in the data source of the row which contains the cell currently being processed.
Value Gets the edit value of the cell currently being processed.

Remarks

To modify the displayed text, change the e.DisplayText parameter value. The following code illustrates how to add the units to the "Distance" cell values. See the end of this article for more examples.

private void gridView1_CustomColumnDisplayText(object sender, CustomColumnDisplayTextEventArgs e) {
    if (e.Column.FieldName == "Distance") {
        e.DisplayText = ((int)e.Value).ToString() + " mil.";
    }
}

To obtain a currently processed row, use the e.ListSourceRowIndex property. Note that it returns the same value for both Auto Filter and New Item rows. If you need to show custom strings in these rows' cells, use the GridView.CustomDrawCell event instead.

private void Gv_CustomDrawCell(object sender, XtraGrid.Views.Base.RowCellCustomDrawEventArgs e)
{
    if (e.RowHandle == GridControl.AutoFilterRowHandle)
        e.DisplayText = "AutoFilterRow";
    if (e.RowHandle == GridControl.NewItemRowHandle)
        e.DisplayText = "NewItemRow";
}

Modify group row captions

Read the e.IsForGroupRow event parameter to identify whether the event was raised for a group row. In the code sample below, the CustomColumnDisplayText event handler adds the item counter to Kanban Board group captions.

tileView1.CustomColumnDisplayText += TileView1_CustomColumnDisplayText;

private void TileView1_CustomColumnDisplayText(object sender, CustomColumnDisplayTextEventArgs e) {
    if (e.IsForGroupRow) {
        e.DisplayText = string.Format("{0} ({1})", e.DisplayText, CalcGroupCount(e.GroupRowHandle));
    }
}

int CalcGroupCount(int groupRowHandle) {
    int groupIndex = Math.Abs(groupRowHandle) - 1;
    return tileView1.DataController.GroupInfo[groupIndex].ChildControllerRowCount;
}

Modify filter menu item captions

If the event’s ListSourceRowIndex parameter returns the value of the static GridControl.InvalidRowHandle field, the event was raised for a filter menu item. Use this to rename filter items in drop-down filter menus.

private void gridView1_CustomColumnDisplayText(object sender, DevExpress.XtraGrid.Views.Base.CustomColumnDisplayTextEventArgs e) {
    if (e.Column.FieldName == "Distance" && e.ListSourceRowIndex == GridControl.InvalidRowHandle) {
        //change the e.DisplayText here
    }
}

Note that you should only do that for classic drop-down menus (lists). For Excel-style menus (see the ColumnViewOptionsFilter.ColumnFilterPopupMode property), use the ColumnView.FilterPopupExcelData event instead.

Important notes

  • When you change cell display texts, underlying values remain unchanged. Data Grid uses these data-layer values to filter and sort records. For that reason, if you handle the CustomColumnDisplayText event, you may also want to switch the GridColumn.SortMode and GridColumn.FilterMode to DisplayText. Note that in this case, Data Grid will work with string values instead of real data source objects.

  • Instead of replacing cell display texts on the CustomColumnDisplayText event, you can create an unbound column and handle the ColumnView.CustomUnboundColumnData event to supply this column with values. Often, this is the better approach since it does not affect Grid filters, nor forces you to change SortMode and FilterMode properties.

  • The CustomColumnDisplayText event does not allow you to provide or modify text within cells that contain non-textbox-based editors (e.g., PictureEdit, ImageEdit, CheckEdit, RadioGroup, ToggleSwitch, SparklineEdit).

Example 2

The following example demonstrates how to provide custom display text for data cells via the ColumnView.CustomColumnDisplayText event. In the example empty strings are displayed within the "Discount" column's cells if they contain zero values.

The result is shown below:

ColumnView.CustomColumnDisplayText

using DevExpress.XtraGrid.Views.Base;

private void gridView1_CustomColumnDisplayText(object sender, 
CustomColumnDisplayTextEventArgs e) {
   if(e.Column.FieldName == "Discount")
      if(Convert.ToDecimal(e.Value) == 0) e.DisplayText = "";
}

Example 3

The following example shows how to dynamically customize the cell's display text by handling the ColumnView.CustomColumnDisplayText event.

The grid View in the example contains the CurrencyType and Price columns. If the currency type is equal to 0, the price is displayed in dollars; if it is equal to 1, it is displayed in euros.

CD_Formatting_EuroDollar_Ex

using DevExpress.XtraGrid.Views.Base;
using System.Globalization;

// The cultures used to format the values for the two different currencies.
CultureInfo ciUSA = new CultureInfo("en-US");
CultureInfo ciEUR = new CultureInfo("fr-FR", false);

private void gridView1_CustomColumnDisplayText(object sender, CustomColumnDisplayTextEventArgs e) {
    ColumnView view = sender as ColumnView;
    if (e.Column.FieldName == "Price" && e.ListSourceRowIndex != DevExpress.XtraGrid.GridControl.InvalidRowHandle)
    {
        int currencyType = (int)view.GetListSourceRowCellValue(e.ListSourceRowIndex, "CurrencyType");
        decimal price = Convert.ToDecimal(e.Value);
        switch (currencyType)
        {
            case 0: e.DisplayText = string.Format(ciUSA, "{0:c}", price); break;
            case 1: e.DisplayText = string.Format(ciEUR, "{0:c}", price); break;
        }
    }
}
See Also