LayoutControl.BeginUpdate() Method

Locks the LayoutControl object by preventing visual updates of the object and its elements until the EndUpdate method is called.

Namespace: DevExpress.XtraLayout

Assembly: DevExpress.XtraLayout.v19.1.dll

Declaration

C#

public void BeginUpdate()

VB.NET

Public Sub BeginUpdate

Remarks

The BeginUpdate and EndUpdate methods allow you to avoid flickering while performing batch modifications to the LayoutControl‘s settings. Once the BeginUpdate method has been called, modifying settings of the LayoutControl and its elements does not cause an immediate visual update. So, multiple modifications can be made to the object and its elements without a major impact on performance or screen flickering. After all the desired operations have been finished, call the EndUpdate method.

The BeginUpdate and EndUpdate methods use an internal counter to implement the update functionality. The counter’s initial value is 0. Visual updates are forbidden if the counter’s value is greater than 0, and the updates are enabled if the counter’s value is 0. The BeginUpdate method increments the counter. The EndUpdate method decrements the counter. If the counter’s new value is 0, an immediate visual update occurs. Each call to BeginUpdate must be paired with a call to EndUpdate. To ensure that EndUpdate is always called even if an exception occurs, use the try…finally statement.

Note

When adding multiple layout items to the layout, do not execute this code within the BeginUpdate/EndUpdate block. A newly added item’s positions and bounds must be recalculated before adding the next item. Within the BeginUpdate/EndUpdate block, all calculations are locked.

Related GitHub Examples

The following code snippets (auto-collected from DevExpress Examples) contain references to the BeginUpdate() method.

Note

The algorithm used to collect these code examples remains a work in progress. Accordingly, the links and snippets below may produce inaccurate results. If you encounter an issue with code examples below, please use the feedback form on this page to report the issue.

C#

how-to-implement-the-insert-document-field-dialog-winforms-version-t223036/CS/WindowsFormsApplication1/InsertFieldModules/InsertFieldDialog.cs#L71

InsertFieldRichEditHelper.CurrentVariableType = listBoxFieldNames.SelectedItem.ToString();
layoutControl1.BeginUpdate();
Control previousControl = layoutControlItemMainContent.Control;

XAF_how-to-highlight-the-focused-editor-in-detailview-e2106/CS/WinWebSolution.Module.Win/WinHighlightFocusedLayoutItemDetailViewController.cs#L12

if (layoutControl != null) {
    layoutControl.BeginUpdate();
    layoutControl.OptionsView.HighlightFocusedItem = true;

VB.NET

how-to-implement-the-insert-document-field-dialog-winforms-version-t223036/VB/WindowsFormsApplication1/InsertFieldModules/InsertFieldDialog.vb#L73

InsertFieldRichEditHelper.CurrentVariableType = listBoxFieldNames.SelectedItem.ToString()
layoutControl1.BeginUpdate()
Dim previousControl As Control = layoutControlItemMainContent.Control

XAF_how-to-highlight-the-focused-editor-in-detailview-e2106/VB/WinWebSolution.Module.Win/WinHighlightFocusedLayoutItemDetailViewController.vb#L14

If layoutControl IsNot Nothing Then
    layoutControl.BeginUpdate()
    layoutControl.OptionsView.HighlightFocusedItem = True