ControlDestroying Event

Active Query Builder 2 .NET Edition reference

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Visual Basic (Declaration)
Visual Basic (Usage)
C#
Managed Extensions for C++

ActiveDatabaseSoftware.ActiveQueryBuilder Namespace > QueryBuilder Class : ControlDestroying Event

Invoked before the control is destroyed inside the component.

Syntax

Visual Basic
C#
Managed Extensions for C++

'Declaration
 
Public Event ControlDestroying As ControlDestroyingEventHandler

'Usage
 
Dim instance As QueryBuilder
Dim handler As ControlDestroyingEventHandler
 
AddHandler instance.ControlDestroying, handler

public event ControlDestroyingEventHandler ControlDestroying

public: __event ControlDestroyingEventHandler* ControlDestroying

Remarks

Use this event to free resources and unbound events created in the ControlCreated Event

Example

Removes button at the top of each sub-query DataSource control created in the ControlCreated event handler.

private void queryBuilder1_ControlDestroying(ControlOwner owner, Control control)
{
    if (owner is DataSourceQuery && control is DataSourceControl)
    {
        DataSourceControl dataSourceControl = (DataSourceControl) control;
 
        foreach (Control c in dataSourceControl.Controls)
        {
            if (c is Button)
            {
                // remove event handler to avoid memory leak
                c.Click -= customButton_Click;
                break;
            }
        }
    }
}

Reference

QueryBuilder Class
QueryBuilder Members

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