Disabled Cell Behavior

• Jan 03, 2024
• 4 minutes to read

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

Run Demo

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 to create the behavior.

  

• Select the Disabled Cell Behavior. Use its Target property to attach the behavior to a control.

  

Behavior Settings

• Appearance – Specifies appearance settings applied to disabled cells. You can change the background color, font style, etc. Default appearance settings depend on the active skin.

• Expression – Specifies a condition that disabled rows should meet. For example, DateDiffMonth([SalesDate], Today()) > 6 disables rows with orders that are older than six months.

  Click the property’s ellipsis button to invoke the Expression Editor:

  

• ProcessingCell – Handle this event to enable/disable cells based on a specific condition.

  Use the e.FieldName event argument to obtain the processed cell’s field name (column).

  The e.RecordId argument identifies the row/node/record that contains the processed cell. The e.RecordId argument returns the following values depending on the attached control:

  Control	e.RecordId Argument Description
  GridControl	The index of the data source record that corresponds to the processed grid row. Use the GetRowHandle(Int32) method to get the grid row’s handle. The GetRow(Int32) method returns the processed data source record.
  VGrid	The index of the data source record that corresponds to the processed record. Use the GetRecordObject(Int32) method to get the processed data source record.
  TreeList	The processed node’s Id property value. Use the GetRow(Int32) method to get the processed data source record.

  Set the e.Disabled argument to true to disable the processed cell.

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

Important

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

Example: Handle the ProcessingCell Event

The following example disables rows only if the user checked the check box displayed on the Form (the checkEdit1 control), but never disables cells in the ‘Order ID’ column.

C#

using DevExpress.Utils.Behaviors.Common;

public Form1() {
    InitializeComponent();
    disabledCellEvents1.ProcessingCell += DisabledCellEvents1_ProcessingCell;
}

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

Public Sub New()
    InitializeComponent()
    disabledCellEvents1.ProcessingCell += DisabledCellEvents1_ProcessingCell
End Sub

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

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)