Question

c# RotateTransform 为什么 扭曲

public Bitmap Rotate(Bitmap b, int angle) { angle = angle % 360; //弧度转换 double radian = angle * Math.PI / 180.0; double cos = Math.Cos(radian); double sin = Math.Sin(radian); //原图的宽和高 int w = b.Width; int h = b.Height; int W = (int)(Math.Max(Math.Abs(w * cos - h * sin), Math.Abs(w * cos + h * sin))); int H = (int)(Math.Max(Math.Abs(w * sin - h * cos), Math.Abs(w * sin + h * cos))); //目标位图 Bitmap dsImage = new Bitmap(W, H); System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(dsImage); g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.Bilinear; g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality; //计算偏移量 Point Offset = new Point((W - w) / 2, (H - h) / 2); //构造图像显示区域：让图像的中心与窗口的中心点一致 Rectangle rect = new Rectangle(Offset.X, Offset.Y, w, h); Point center = new Point(rect.X + rect.Width / 2, rect.Y + rect.Height / 2); g.TranslateTransform(center.X, center.Y); g.RotateTransform(360 - angle); //恢复图像在水平和垂直方向的平移 g.TranslateTransform(-center.X, -center.Y); g.DrawImage(b, rect); //重至绘图的所有变换 g.ResetTransform(); g.Save(); g.Dispose(); //dsImage.Save("yuancd.jpg", System.Drawing.Imaging.ImageFormat.Jpeg); return dsImage; } #endregion 图片旋转函数上图是原图和旋转30度后的图像，旋转后图像为什么不是长方形了，每个角度不是90度了

Answer 1

我测试过旋转后图形角度没变。猜测有可能是你第二个pictureBox2长宽比不对，你先试试把它拖大些，且属性SizeMode = Normal。