Disabled Cell Behavior

• Nov 07, 2019
• 3 minutes to read

Overview

This Behavior allows you to disable cells in rows that meet a certain condition. Disabled cells are grayed-out according to the skin settings. Users cannot edit disabled cells. For example, you can disable rows that display orders that are older than six months.

Supported Controls

• GridControl
• VGridControl
• TreeList

How to Attach the Behavior to a Control in the Designer

To attach the Behavior to a control, use the standard approach:

• Drop the BehaviorManager component from Visual Studio’s Toolbox onto the component tray.
• Click Edit Behaviors in the component’s smart tag menu.
• In the Add drop-down menu, select Disabled Cell Behavior.

Options

When the Behavior is attached, use the editor to specify the following options:

• The Appearance property — appearance settings applied to disabled cells. The default settings depend on the current skin. This property allows you to adjust them. For example, you can change the background color, font style, and so on.

• The Expression property — a string value that specifies a condition that disabled rows should meet. For example, DateDiffMonth([Sales Date], Today()) > 6 disables rows with orders that are older than six months.

  Click the property’s ellipsis button to invoke the expression editor.

  

• The ProcessingCell event — allows you to enable/disable a cell.

  Use the FieldName and RecordId event arguments to identify the processed cell. The Disabled argument gets or sets whether the cell is disabled.

  The code below disables rows only if the user checked a dedicated option, but never disables cells in the ‘Order ID’ column.

  

  C#

  using DevExpress.Utils.Behaviors.Common;
  
  private void disabledCellEvents1_ProcessingCell(object sender, ProcessCellEventArgs e) {
      bool evaluationResult = e.Disabled;
      evaluationResult = checkEdit1.Checked ? evaluationResult : false;
      e.Disabled = e.FieldName == "OrderID" ? false : evaluationResult;
  }
  // Use the grid view's LayoutChanged method to force the Behavior
  // to recalculate disabled cells.
  private void checkEdit1_CheckedChanged(object sender, EventArgs e) {
      gridView1.LayoutChanged();
  }
  

  VB.NET

  Imports DevExpress.Utils.Behaviors.Common
  
  Private Sub disabledCellEvents1_ProcessingCell(ByVal sender As Object, ByVal e As ProcessCellEventArgs) _
      Handles disabledCellEvents1.ProcessingCell
      Dim evaluationResult As Boolean = e.Disabled
      evaluationResult = If(checkEdit1.Checked, evaluationResult, False)
      e.Disabled = If(e.FieldName = "OrderID", False, evaluationResult)
  End Sub
  ' Use the grid view's LayoutChanged method to force the Behavior
  ' to recalculate disabled cells.
  Private Sub checkEdit1_CheckedChanged(ByVal sender As Object, ByVal e As EventArgs) _
      Handles checkEdit1.CheckedChanged
      gridView1.LayoutChanged()
  End Sub
  

  Note

  See Code Examples in the XtraGrid demo for more samples.

  You can add an event handler in the editor’s events tab, or use the DisabledCellEvents component in the Properties window.

  

How to Attach the Behavior to a Control in Code

The example below shows how to attach the Behavior to a control in code, specify its settings, and add event handlers.

C#

using DevExpress.Utils.Behaviors;
using DevExpress.Utils.Behaviors.Common;

BehaviorManager bm = new BehaviorManager(this.components);
bm.Attach<DisabledCellBehavior>(gridView1, behavior => {
    behavior.Properties.Expression = "DateDiffMonth([Sales Date], Today()) > 6";
    behavior.Properties.Appearance.BackColor = System.Drawing.Color.AliceBlue;
    behavior.Properties.Appearance.FontStyleDelta = System.Drawing.FontStyle.Italic;
    behavior.ProcessingCell += (s, e) => { if (!checkEdit1.Checked) e.Disabled = false; };
});

// Use the Detach method to remove the Behavior.
bm.Detach<DisabledCellBehavior>(gridView1);

VB.NET

Imports DevExpress.Utils.Behaviors
Imports DevExpress.Utils.Behaviors.Common

Dim bm As New BehaviorManager(Me.components)
bm.Attach(Of DisabledCellBehavior)(gridView1, Sub(behavior)
    behavior.Properties.Expression = "DateDiffMonth([Sales Date], Today()) > 6"
    behavior.Properties.Appearance.BackColor = System.Drawing.Color.AliceBlue
    behavior.Properties.Appearance.FontStyleDelta = System.Drawing.FontStyle.Italic
    AddHandler behavior.ProcessingCell, Sub(s, e)
        If Not checkEdit1.Checked Then
            e.Disabled = False
        End If
    End Sub
End Sub)

' Use the Detach method to remove the Behavior.
bm.Detach(Of DisabledCellBehavior)(gridView1)