InkCanvas橡皮擦 [英] InkCanvas Eraser

问题描述

我的画板为InkCanvas；我想更改橡皮擦的大小，所以写了:

I have sketchpad as InkCanvas; I want to change size of eraser so I've written:

Private Sub Sketchpad_KeyDown(sender As System.Object, e As System.Windows.Input.KeyEventArgs) Handles Sketchpad.KeyDown

If e.Key = Key.OemMinus Then

' Decrease size of Eraser to 5*5 

Sketchpad.EraserShape = New RectangleStylusShape(5, 5)

End If

If e.Key = Key.OemPlus Then

' Increase size of Eraser to 50*50 

Sketchpad.EraserShape = New RectangleStylusShape(50, 50)

End If

If e.Key = Key.I Then
' Change editing mode to Ink
Sketchpad.EditingMode = InkCanvasEditingMode.Ink

End If

If e.Key = Key.E Then
' Change editing mode to Eraser
Sketchpad.EditingMode = InkCanvasEditingMode.EraseByPoint

End If

End Sub

尝试一下:

1. 通过按e选择橡皮擦，橡皮擦笔尖将显示为矩形
2. 按+号增加大小，您将看不到任何更改.为什么?
3. 现在按i更改编辑模式，将出现墨水笔尖.
4. 再次按e切换到橡皮擦.您将看到橡皮擦形状已更改.

为什么不按+号呢?

推荐答案

来自如果更改EraserShape，则在下一次EditingMode更改之前，不会更新InkCanvas上呈现的光标."

"If you change the EraserShape, the cursor rendered on the InkCanvas is not updated until the next EditingMode change."

我测试了以下代码，它可以正常工作:

I tested the following code and it works fine:

if (e.Key == Key.OemMinus)
{
    ink.EraserShape = new RectangleStylusShape(5, 5);
    var editMode = ink.EditingMode;
    ink.EditingMode = InkCanvasEditingMode.None;
    ink.EditingMode = editMode;
}
if (e.Key == Key.OemPlus)
{
    ink.EraserShape = new RectangleStylusShape(50, 50);
    var editMode = ink.EditingMode;
    ink.EditingMode = InkCanvasEditingMode.None;
    ink.EditingMode = editMode;
}

这篇关于InkCanvas橡皮擦的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！