InkCanvas 上的重做功能

Question

我正在使用 windows 10 build 14939 中的 InkCanvas 和 InkToolBar 来捕获用户墨迹笔划。

我想用 Undo/Redo 做一个自定义按钮，但是我无法创建以下按钮：

private static InkStroke CreateStroke(List<InkPoint> redoInkPoints) {
     var strokeBuilder = new InkStrokeBuilder();
     Matrix3x2 matr = new Matrix3x2();
     return strokeBuilder.CreateStrokeFromInkPoints(redoInkPoints, matr);
}

然而 visual studio 对

的 matr 变量的抱怨

'Argment type 'System.Numerics.Matrix3x2' is not assignable to parameter type 'Windows.Foundation.Numerics.Matrix3x2'

即使我的代码中没有任何地方引用 windows.foundation.numerics.matrix3x2.

有人知道我如何使用 CreateStrokeFromInkPoints 吗？

Answer 1

根据您的代码，我认为这里的问题是您在表示单位矩阵的 InkStrokeBuilder.CreateStrokeFromInkPoints method. While using Matrix3x2 matr = new Matrix3x2();, you are creating a zero matrix. It would collapse all your points into a singularity, which is not a valid value here. To fix this issue, you may use System.Numerics.Matrix3x2.Identity 属性中使用了错误的矩阵。以下是一个简单的示例：

XAML:

<StackPanel>
    <InkCanvas x:Name="inkCanvas" Width="500" Height="200" />
    <Button Click="Button_Click">Add a stroke</Button>
</StackPanel>

代码隐藏：

private void Button_Click(object sender, RoutedEventArgs e)
{
    List<InkPoint> inkPoints = new List<InkPoint> { new InkPoint(new Point(10, 10), 0.5f), new InkPoint(new Point(100, 100), 0.5f) };

    InkStroke stroke = CreateStroke(inkPoints);

    inkCanvas.InkPresenter.StrokeContainer.AddStroke(stroke);
}

private static InkStroke CreateStroke(List<InkPoint> redoInkPoints)
{
    var strokeBuilder = new InkStrokeBuilder();
    System.Numerics.Matrix3x2 matr = System.Numerics.Matrix3x2.Identity;
    return strokeBuilder.CreateStrokeFromInkPoints(redoInkPoints, matr);
}

InkCanvas 上的重做功能

Redo functionality on InkCanvas

inkcanvas

uwp