图像旋转的C#示例
2021-08-08 13:21:24

private void RotateTransform_Click(object sender, System.EventArgs e)
        {
            Graphics graphics=this.CreateGraphics();
            graphics.Clear(Color.White);

            //装入图片
            Bitmap image=new Bitmap("nemo.bmp");

            //获取当前窗口的中心点
            Rectangle rect=new Rectangle(0,0,this.ClientSize.Width,this.ClientSize.Height);
            PointF center=new PointF(rect.Width/2,rect.Height/2);

            float offsetX=0;
            float offsetY=0;
            offsetX=center.X-image.Width/2;
            offsetY=center.Y-image.Height/2;
            //构造图片显示区域:让图片的中心点与窗口的中心点一致
            RectangleF picRect=new RectangleF(offsetX,offsetY,image.Width,image.Height);
            PointF Pcenter=new PointF(picRect.X+picRect.Width/2,
                picRect.Y+picRect.Height/2);
    
            //让图片绕中心旋转一周
            for(int i=0;i<361;i+=10)
            {
                // 绘图平面以图片的中心点旋转
                graphics.TranslateTransform(Pcenter.X, Pcenter.Y);
                graphics.RotateTransform(i);
                //恢复绘图平面在水平和垂直方向的平移
                graphics.TranslateTransform(-Pcenter.X, -Pcenter.Y);
                //绘制图片并延时
                graphics.DrawImage(image,picRect);    
                Thread.Sleep(100);
                //重置绘图平面的所有变换
                graphics.ResetTransform();
            }
       }