如何将 System.Drawing.Image 旋转 x 度？

Question

我需要将汽车图像旋转 X 度以指示行驶方向。现在我有这个工作代码可以在 GDI+ 表面上绘制图像。

int hdc = Display.hDC;
IntPtr p = new IntPtr(hdc);
graphics = Graphics.FromHdc(p);
newImage = Image.FromFile(carImage);
System.Drawing.Point ulCorner = new System.Drawing.Point(x - 25, y -15);

//graphics.RotateTransform(45); //tried this line, when i used it, it drew nothing.
graphics.DrawImage(newImage, ulCorner);

如何旋转X度？

Answer 1

以下是旋转图像的方法

 //move rotation point to center of image
  graphics.TranslateTransform((float)newImage.Width/2,(float)newImage.Height / 2);
  //rotate
  graphics.RotateTransform(angle);
  //move image back
  graphics.TranslateTransform(-(float)newImage.Width/2,-(float)newImage.Height / 2);