ManipulationDeltaEventArgs.IsInertial Property

Gets a value that indicates whether the ManipulationDelta event occurs during inertia.

Namespace:  System.Windows.Input
Assembly:  PresentationCore (in PresentationCore.dll)

public bool IsInertial { get; private set; }

Property Value

Type: System.Boolean
true if the ManipulationDelta event occurs during inertia; false if the event occurs while the user has contact with the UIElement.

You can use this method to determine whether the ManipulationDelta event occurs during inertia or while the user has contact with the element that receives the ManipulationDelta event.

The following example shows an event handler for the ManipulationDelta event. The example checks whether the ManipulationDelta event occurred during inertia and whether the rectangle is touching the edge of a window. If those cases are true, the application stops the manipulation to prevent the rectangle from leaving the visible area of the application. This example is part of a larger example in Walkthrough: Creating Your First Touch Application.

void Window_ManipulationDelta(object sender, ManipulationDeltaEventArgs e)
{

    // Get the Rectangle and its RenderTransform matrix.
    Rectangle rectToMove = e.OriginalSource as Rectangle;
    Matrix rectsMatrix = ((MatrixTransform)rectToMove.RenderTransform).Matrix;

    // Rotate the Rectangle.
    rectsMatrix.RotateAt(e.DeltaManipulation.Rotation, 
                         e.ManipulationOrigin.X, 
                         e.ManipulationOrigin.Y);

    // Resize the Rectangle.  Keep it square 
    // so use only the X value of Scale.
    rectsMatrix.ScaleAt(e.DeltaManipulation.Scale.X, 
                        e.DeltaManipulation.Scale.X, 
                        e.ManipulationOrigin.X,
                        e.ManipulationOrigin.Y);

    // Move the Rectangle.
    rectsMatrix.Translate(e.DeltaManipulation.Translation.X,
                          e.DeltaManipulation.Translation.Y);

    // Apply the changes to the Rectangle.
    rectToMove.RenderTransform = new MatrixTransform(rectsMatrix);

    Rect containingRect =
        new Rect(((FrameworkElement)e.ManipulationContainer).RenderSize);

    Rect shapeBounds =
        rectToMove.RenderTransform.TransformBounds(
            new Rect(rectToMove.RenderSize));

    // Check if the rectangle is completely in the window.
    // If it is not and intertia is occuring, stop the manipulation.
    if (e.IsInertial && !containingRect.Contains(shapeBounds))
    {
        e.Complete();
    }


    e.Handled = true;
}

.NET Framework

Supported in: 4.5.3, 4

.NET Framework Client Profile

Supported in: 4

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

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

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