CheckForIllegalCrossThreadCalls Property
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Control.CheckForIllegalCrossThreadCalls Property

Gets or sets a value indicating whether to catch calls on the wrong thread that access a control's Handle property when an application is being debugged.

Namespace: System.Windows.Forms
Assembly: System.Windows.Forms (in

public static bool CheckForIllegalCrossThreadCalls { get; set; }
/** @property */
public static boolean get_CheckForIllegalCrossThreadCalls ()

/** @property */
public static void set_CheckForIllegalCrossThreadCalls (boolean value)

public static function get CheckForIllegalCrossThreadCalls () : boolean

public static function set CheckForIllegalCrossThreadCalls (value : boolean)

Not applicable.

Property Value

true if calls on the wrong thread are caught; otherwise, false.

When a thread other than the creating thread of a control tries to access one of that control's methods or properties, it often leads to unpredictable results. A common invalid thread activity is a call on the wrong thread that accesses the control's Handle property. Set CheckForIllegalCrossThreadCalls to true to find and diagnose this thread activity more easily while debugging. Note that illegal cross-thread calls will always raise an exception when an application is started outside the debugger.

Windows 98, Windows Server 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0

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