DynamicRenderer.OnDraw 方法

定義

命名空間:

System.Windows.Input.StylusPlugIns

組件:

PresentationCore.dll

即時繪製筆墨，使筆墨看起來像是「順著」Tablet 畫筆或其他指向裝置出現一樣。

protected:
 virtual void OnDraw(System::Windows::Media::DrawingContext ^ drawingContext, System::Windows::Input::StylusPointCollection ^ stylusPoints, System::Windows::Media::Geometry ^ geometry, System::Windows::Media::Brush ^ fillBrush);

protected virtual void OnDraw (System.Windows.Media.DrawingContext drawingContext, System.Windows.Input.StylusPointCollection stylusPoints, System.Windows.Media.Geometry geometry, System.Windows.Media.Brush fillBrush);

abstract member OnDraw : System.Windows.Media.DrawingContext * System.Windows.Input.StylusPointCollection * System.Windows.Media.Geometry * System.Windows.Media.Brush -> unit
override this.OnDraw : System.Windows.Media.DrawingContext * System.Windows.Input.StylusPointCollection * System.Windows.Media.Geometry * System.Windows.Media.Brush -> unit

Protected Overridable Sub OnDraw (drawingContext As DrawingContext, stylusPoints As StylusPointCollection, geometry As Geometry, fillBrush As Brush)

參數

drawingContext

DrawingContext

要在其中呈現筆劃的 DrawingContext 物件。

stylusPoints

StylusPointCollection

表示要繪製之筆劃區段的 StylusPointCollection。

geometry

Geometry

表示滑鼠指標路徑的 Geometry。

fillBrush

Brush

指定目前筆劃外觀的筆刷。

範例

下列範例示範如何使用 覆寫 OnDraw 方法來動態轉譯數位筆跡 LinearGradientBrush 。

protected override void OnDraw(DrawingContext drawingContext,
                               StylusPointCollection stylusPoints,
                               Geometry geometry, Brush fillBrush)
{
    // Create a new Brush, if necessary
    if (brush == null)
    {
        Color primaryColor;

        if (fillBrush is SolidColorBrush)
        {
            primaryColor = ((SolidColorBrush)fillBrush).Color;
        }
        else
        {
            primaryColor = Colors.Red;
        }

        brush = new LinearGradientBrush(Colors.Blue, primaryColor, 20d);
    }

    drawingContext.DrawGeometry(brush, null, geometry);
}

Protected Overrides Sub OnDraw(ByVal drawingContext As DrawingContext, _
                               ByVal stylusPoints As StylusPointCollection, _
                               ByVal geometry As Geometry, _
                               ByVal fillBrush As Brush)

    ' Create a new Brush, if necessary
    If brush Is Nothing Then

        Dim primaryColor As Color

        If TypeOf fillBrush Is SolidColorBrush Then
            primaryColor = CType(fillBrush, SolidColorBrush).Color
        Else
            primaryColor = Colors.Red
        End If

        brush = New LinearGradientBrush(Colors.Blue, primaryColor, 20.0)

    End If

    drawingContext.DrawGeometry(brush, Nothing, geometry)

End Sub

給繼承者的注意事項

在 OnDraw(DrawingContext, StylusPointCollection, Geometry, Brush) 衍生類別中覆寫時，請務必呼叫基類的 OnDraw(DrawingContext, StylusPointCollection, Geometry, Brush) 方法。