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WindowPattern.WaitForInputIdle Method

Causes the calling code to block for the specified time or until the associated process enters an idle state, whichever completes first.

Namespace:  System.Windows.Automation
Assembly:  UIAutomationClient (in UIAutomationClient.dll)

public bool WaitForInputIdle(
	int milliseconds


Type: System.Int32
The amount of time, in milliseconds, to wait for the associated process to become idle. The maximum is MaxValue.

Return Value

Type: System.Boolean
true if the window has entered the idle state; false if the timeout occurred.


The parameter passed in is not a valid number.

This method is typically used in conjunction with the handling of a WindowOpenedEvent.

The implementation is dependent on the underlying application framework; therefore this method may return some time after the window is ready for user input. The calling code should not rely on this method to ascertain exactly when the window has become idle.

In the following example, a WindowPattern control pattern is obtained from an AutomationElement and uses WaitForInputIdle to confirm the element is ready for user interaction within a reasonable amount of time.

/// <summary>
/// Obtains a WindowPattern control pattern from an automation element.
/// </summary>
/// <param name="targetControl">
/// The automation element of interest.
/// </param>
/// <returns>
/// A WindowPattern object.
/// </returns>
private WindowPattern GetWindowPattern(AutomationElement targetControl)
    WindowPattern windowPattern = null;

        windowPattern =
            as WindowPattern;
    catch (InvalidOperationException)
        // object doesn't support the WindowPattern control pattern
        return null;
    // Make sure the element is usable.
    if (false == windowPattern.WaitForInputIdle(10000))
        // Object not responding in a timely manner
        return null;
    return windowPattern;

.NET Framework

Supported in: 4, 3.5, 3.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.