Formatting via Events

• Aug 01, 2019
• 4 minutes to read

ASPxGridView has three events that enable you to provide custom display text for individual group rows, data and summary cells. These are:

• ASPxGridView.CustomColumnDisplayText - enables you to provide custom display text for any cell.

  Example 1

  This example demonstrates how to display the “empty” string within the Units On Order column’s cells if they contain zero values.

  The image below shows the result:

  

  C#

  protected void ASPxGridView2_CustomColumnDisplayText(object sender,
      DevExpress.Web.ASPxGridViewColumnDisplayTextEventArgs e) {
      if (e.Column.FieldName != "UnitsOnOrder") return;
      if (Convert.ToInt32(e.Value) == 0)
          e.DisplayText = "empty";
  }
  

  VB.NET

  Protected Sub ASPxGridView1_CustomColumnDisplayText(ByVal sender As Object,_
      ByVal e As DevExpress.Web.ASPxGridViewColumnDisplayTextEventArgs)_
      Handles ASPxGridView1.CustomColumnDisplayText
      If e.Column.FieldName = "UnitsOnOrder" Then
          If Convert.ToInt32(e.Value) = 0 Then
              e.DisplayText = "empty"
          End If
      End If
  End Sub
  

• ASPxGridView.CustomGroupDisplayText - allows you to provide custom content for individual group rows.

  Example 2

  This example demonstrates how to implement custom grouping. The data is grouped by the ‘Unit Price’ column, and the column’s rows that have values between 0 and 10 are combined into a single group. Rows whose values fall between 10 and 20 are combined into another group, etc.

  The ‘Unit Price’ column’s GridDataColumnSettings.SortMode property is set to ‘Custom’, and the ASPxGridView.CustomColumnGroup and ASPxGridView.CustomColumnSort events are handled identically.

  Additionally, the ASPxGridView.CustomGroupDisplayText event is handled to replace the default text displayed within group rows.

  The image below shows the result.

  

  Note

  Refer to the How to implement custom grouping logic for ASPxGridView columns online example to review how it works.

  C#

  protected void ASPxGridView1_CustomColumnSort(object sender, DevExpress.Web.ASPxGridView.CustomColumnSortEventArgs e){
      CompareColumnValues(e);
  }
  
  protected void ASPxGridView1_CustomColumnGroup(object sender, DevExpress.Web.ASPxGridView.CustomColumnSortEventArgs e){
      CompareColumnValues(e);
  }
  
  private void CompareColumnValues(DevExpress.Web.ASPxGridView.CustomColumnSortEventArgs e) {
      if (e.Column.FieldName == "UnitPrice"){
          int res = 0;
  
          double x = Math.Floor(Convert.ToDouble(e.Value1) / 10);
          double y = Math.Floor(Convert.ToDouble(e.Value2) / 10);
          res = Comparer.Default.Compare(x, y);
          if (res < 0) res = -1;
          else if (res > 0) res = 1;
          if (res == 0 || (x > 9 && y > 9)) res = 0;
  
          e.Result = res;
          e.Handled = true;
      }
  }
  
  protected void ASPxGridView1_CustomGroupDisplayText(object sender, DevExpress.Web.ASPxGridView.ASPxGridViewColumnDisplayTextEventArgs e){
      if (e.Column.FieldName == "UnitPrice"){
          double d = Math.Floor(Convert.ToDouble(e.Value) / 10);
          string displayText = string.Format("{0:c} - {1:c} ", d * 10, (d + 1) * 10);
          if (d > 9) displayText = string.Format(">= {0:c} ", 100);
          e.DisplayText = displayText;
      }
  }
  

  VB.NET

  Class SurroundingClass
      Protected Sub ASPxGridView1_CustomColumnSort(ByVal sender As Object, ByVal e As DevExpress.Web.ASPxGridView.CustomColumnSortEventArgs)
          CompareColumnValues(e)
      End Sub
  
      Protected Sub ASPxGridView1_CustomColumnGroup(ByVal sender As Object, ByVal e As DevExpress.Web.ASPxGridView.CustomColumnSortEventArgs)
          CompareColumnValues(e)
      End Sub
  
      Private Sub CompareColumnValues(ByVal e As DevExpress.Web.ASPxGridView.CustomColumnSortEventArgs)
          If e.Column.FieldName = "UnitPrice" Then
              Dim res As Integer = 0
              Dim x As Double = Math.Floor(Convert.ToDouble(e.Value1) / 10)
              Dim y As Double = Math.Floor(Convert.ToDouble(e.Value2) / 10)
              res = Comparer.[Default].Compare(x, y)
  
              If res < 0 Then
                  res = -1
              ElseIf res > 0 Then
                  res = 1
              End If
  
              If res = 0 OrElse (x > 9 AndAlso y > 9) Then res = 0
              e.Result = res
              e.Handled = True
          End If
      End Sub
  
      Protected Sub ASPxGridView1_CustomGroupDisplayText(ByVal sender As Object, ByVal e As DevExpress.Web.ASPxGridView.ASPxGridViewColumnDisplayTextEventArgs)
          If e.Column.FieldName = "UnitPrice" Then
              Dim d As Double = Math.Floor(Convert.ToDouble(e.Value) / 10)
              Dim displayText As String = String.Format("{0:c} - {1:c} ", d * 10, (d + 1) * 10)
              If d > 9 Then displayText = String.Format(">= {0:c} ", 100)
              e.DisplayText = displayText
          End If
      End Sub
  End Class
  

  ASPX

  <dx:ASPxGridView ID="ASPxGridView1" runat="server" AutoGenerateColumns="False" 
      DataSourceID="AccessDataSource1" KeyFieldName="ProductID" 
      OnCustomColumnGroup="ASPxGridView1_CustomColumnGroup" 
      OnCustomColumnSort="ASPxGridView1_CustomColumnSort" 
      OnCustomGroupDisplayText="ASPxGridView1_CustomGroupDisplayText">
  
      <GroupSummary>
          <dx:ASPxSummaryItem SummaryType="Count" />
      </GroupSummary>
  
      <Columns>
          <dx:GridViewDataTextColumn FieldName="ProductID" ReadOnly="True" 
              VisibleIndex="0">
              <EditFormSettings Visible="False" />
          </dx:GridViewDataTextColumn>
          <dx:GridViewDataTextColumn FieldName="ProductName" VisibleIndex="1">
          </dx:GridViewDataTextColumn>
  
          <dx:GridViewDataTextColumn FieldName="UnitPrice" VisibleIndex="2" 
              GroupIndex="0" SortIndex="0" SortOrder="Ascending">
              <PropertiesTextEdit DisplayFormatString="c">
              </PropertiesTextEdit>
              <Settings AllowDragDrop="False" SortMode="Custom" />
          </dx:GridViewDataTextColumn>
  
          <dx:GridViewDataCheckColumn FieldName="Discontinued" VisibleIndex="3">
          </dx:GridViewDataCheckColumn>
      </Columns>
  
      <Settings ShowGroupedColumns="True" ShowGroupPanel="True" />
  </dx:ASPxGridView>
  

  C#

  protected void ASPxGridView1_CustomColumnSort(object sender, DevExpress.Web.ASPxGridView.CustomColumnSortEventArgs e){
      CompareColumnValues(e);
  }
  
  protected void ASPxGridView1_CustomColumnGroup(object sender, DevExpress.Web.ASPxGridView.CustomColumnSortEventArgs e){
      CompareColumnValues(e);
  }
  
  private void CompareColumnValues(DevExpress.Web.ASPxGridView.CustomColumnSortEventArgs e) {
      if (e.Column.FieldName == "UnitPrice"){
          int res = 0;
  
          double x = Math.Floor(Convert.ToDouble(e.Value1) / 10);
          double y = Math.Floor(Convert.ToDouble(e.Value2) / 10);
          res = Comparer.Default.Compare(x, y);
          if (res < 0) res = -1;
          else if (res > 0) res = 1;
          if (res == 0 || (x > 9 && y > 9)) res = 0;
  
          e.Result = res;
          e.Handled = true;
      }
  }
  
  protected void ASPxGridView1_CustomGroupDisplayText(object sender, DevExpress.Web.ASPxGridView.ASPxGridViewColumnDisplayTextEventArgs e){
      if (e.Column.FieldName == "UnitPrice"){
          double d = Math.Floor(Convert.ToDouble(e.Value) / 10);
          string displayText = string.Format("{0:c} - {1:c} ", d * 10, (d + 1) * 10);
          if (d > 9) displayText = string.Format(">= {0:c} ", 100);
          e.DisplayText = displayText;
      }
  }
  

• ASPxGridView.SummaryDisplayText - enables custom display text to be provided for any total or group summary value.