Disabled Cell Behavior

• Mar 28, 2023
• 4 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.

Note

The Disabled Cell Behavior does not prevent users from pasting (Ctrl+V) data into disabled Data Grid or Tree List cells, if the control’s OptionsClipboard.PasteMode property is set to Update.

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 event arguments to get the processed cell’s field name. The RecordId argument identifies the row/node/record that contains the processed cell. This argument returns the following values depending on the attached control:

  • For a GridControl — the index of the data source record that corresponds to the processed grid row. You can use the GetRowHandle(Int32) method to get the grid row’s handle. To get the processed data source record, use the GetRow(Int32) method.
  • For a VGridControl — the index of the data source record that corresponds to the processed grid record. To get the processed data source record, use the GetRecordObject(Int32) method.
  • For a TreeList — the processed node’s Id property value. To get the processed data source record, use the GetRow(Int32) method.

  Set the Disabled argument to true to disable the processed cell. The code below disables rows only if the user checked a dedicated option (a standalone CheckEdit - checkEdit1), 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
  

  Run Demo

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

  

Important

Customizations made in the ShowingEditor or RowCellStyle event handlers take priority over Disabled Cell Behavior.

How to Attach the Behavior to a Control in Code

The following example demonstrates how to attach the Behavior to a Grid control in code, specify its settings, and add event handlers:

C#

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

BehaviorManager bm;

public MyForm() {
    InitializeComponent();
    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 BehaviorManager

Public Sub MyForm()
    InitializeComponent()
    bm = 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)
End Sub

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