根据旋转的文本框旋转光标 [英] Rotating Cursor According to Rotated TextBox

问题描述

我有一个 TextBox 允许我的用户旋转.但我希望我的用户能够让他们的 Cursor 旋转到与 TextBox 旋转相同的角度.例如，如果他们将 TextBox 旋转到 28°，那么当 Cursor 进入该 TextBox 时，Cursor 应该也将自身旋转到 28°.

I have a TextBox that I allow my users to rotate. But what I would LOVE for my users is to have their Cursor rotate to the same angle that the TextBox was rotated at. For example, if they rotated the TextBox to 28°, then when the Cursor enters that TextBox the Cursor should also rotate itself to 28°.

推荐答案

您可以使用 WinForms 中的 System.Drawing.Icon 类结合 WPF 的位图旋转功能来旋转光标.

You can rotate your cursor using the System.Drawing.Icon class from WinForms in combination with WPF's bitmap rotation ability.

这样做的方法是加载图标，将其转换为 BitmapSource，使用 Image 和 RenderTargetBitmap 对其进行旋转，将其转换回 Icon，保存，最后更新字节 2、10 和 11它是 .cur 而不是 .ico.

The way to do this is to load the icon, convert it to a BitmapSource, use Image and RenderTargetBitmap to rotate it, convert it back to an Icon, save it, and finally update bytes 2, 10, and 11 that make it a .cur instead of a .ico.

代码如下:

public Cursor GetRotatedCursor(byte[] curFileBytes, double rotationAngle)
{
  // Load as Bitmap, convert to BitmapSource
  var origStream = new MemoryStream(curFileBytes);
  var origBitmap = new System.Drawing.Icon(origStream).ToBitmap();
  var origSource = System.Windows.Interop.Imaging.CreateBitmapSourceFromHBitmap(origBitmap.GetHBitmap());

  // Construct rotated image
  var image = new Image
  {
    BitmapSource = origSource,
    RenderTransform = new RotateTransform(rotationAngle)
  };

  // Render rotated image to RenderTargetBitmap
  var width = origBitmap.Width;
  var height = origBitmap.Height;
  var resultSource = new RenderTargetBitmap(width, height, 96, 96, PixelFormats.Pbgra32);
  resultSource.Render(image);

  // Convert to System.Drawing.Bitmap
  var pixels = new int[width*height];
  resultSource.CopyPixels(pixels, width, 0);
  var resultBitmap = new System.Drawing.Bitmap(width, height, System.Drawing.Imaging.PixelFormat.Format32bppPargb);
  for(int y=0; y<height; y++)
    for(int x=0; x<width; x++)
      resultBitmap.SetPixel(x, y, Color.FromArgb(pixels[y*width+x]));

  // Save to .ico format
  var resultStream = new MemoryStream();
  new System.Drawing.Icon(resultBitmap.GetHIcon()).Save(resultStream);

  // Convert saved file into .cur format
  resultStream.Seek(2); resultStream.WriteByte(curFileBytes, 2, 1);
  resultStream.Seek(10); resultStream.WriteByte(curFileBytes, 10, 2);
  resultStream.Seek(0);

  // Construct Cursor
  return new Cursor(resultStream);
}

如果你想避免循环，你可以用一小段usafe代码替换它来调用接受初始化数据的System.Drawing.Bitmap构造函数:

If you want to avoid the loop, you can replace it with a small bit of usafe code to call the System.Drawing.Bitmap constructor that takes initialization data:

  fixed(int* bits = pixels)
  {
    resultBitmap = new System.Drawing.Bitmap(width, height, width, System.Drawing.Imaging.PixelFormat.Format32bppPargb, new IntPtr(bits));
  }

每次您的 TextBox 旋转发生变化时，您都需要调用它.这可以通过旋转 TextBox 的代码来完成，也可以通过绑定到 TextBox 旋转的值上的 PropertyChangedCallback 来完成.

You'll need to call this every time your TextBox rotation changes. This can be done either from the code that rotates your TextBox, or from a PropertyChangedCallback on a value that is bound to the TextBox's rotation.

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