圖像旋轉的C#示例

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

            //裝入圖片
            Bitmap image=new Bitmap("nemo.bmp");

            //獲取當前窗口的中心點
            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;
            //構造圖片顯示區域:讓圖片的中心點與窗口的中心點一致
            RectangleF picRect=new RectangleF(offsetX,offsetY,image.Width,image.Height);
            PointF Pcenter=new PointF(picRect.X+picRect.Width/2,
                picRect.Y+picRect.Height/2);
    
            //讓圖片繞中心旋轉一週
            for(int i=0;i<361;i+=10)
            ...{
                // 繪圖平面以圖片的中心點旋轉
                graphics.TranslateTransform(Pcenter.X, Pcenter.Y);
                graphics.RotateTransform(i);
                //恢復繪圖平面在水平和垂直方向的平移
                graphics.TranslateTransform(-Pcenter.X, -Pcenter.Y);
                //繪製圖片並延時
                graphics.DrawImage(image,picRect);    
                Thread.Sleep(100);
                //重置繪圖平面的所有變換
                graphics.ResetTransform();
            }
        }