一个坐标点围绕任意中心点旋转--C#实现分类： C#/ASP.net 重用代码之C# 2011-07-19 20:23 1668人阅读 评论(0) 收藏 举报            假设对图片上任意点(x,y)，绕一个坐标点(rx0,ry0)逆时针旋转RotaryAngle角度后的新的坐标设为(x', y')，有公式：    x'= (x - rx0)*cos(RotaryAngle) + (y - ry0)*sin(RotaryAngle) + rx0 ;    y'=-(x - rx0)*sin(RotaryAngle) + (y - ry0)*cos(RotaryAngle) + ry0 ;[csharp] view plaincopy/// 
          /// 对一个坐标点按照一个中心进行旋转          /// 
          /// 中心点          /// 要旋转的点          /// 旋转角度，笛卡尔直角坐标          /// 
               private  Point PointRotate(Point center, Point p1, double angle)          {              Point tmp = new Point();              double angleHude = angle * Math.PI / 180;/*角度变成弧度*/              double x1 = (p1.X - center.X) * Math.Cos(angleHude) + (p1.Y - center.Y ) * Math.Sin(angleHude) + center .X;              double y1 = -(p1.X - center.X) * Math.Sin(angleHude) + (p1.Y - center.Y) * Math.Cos(angleHude) + center.Y;              tmp.X = (int)x1;              tmp.Y = (int)y1;              return tmp;          }

 

 

 

1 、旋转e.Graphics.RotateTransform(30.0F, MatrixOrder.Prepend);2、平移 e.Graphics.TranslateTransform(100.0F, 0.0F);3、缩放 e.Graphics.ScaleTransform(3.0F, 1.0F, MatrixOrder.Append);4、点坐标变换            e.Graphics.TranslateTransform(40, 30);            e.Graphics.TransformPoints(CoordinateSpace.Page, CoordinateSpace.World, points);            e.Graphics.ResetTransform();     // Create array of two points.            Point[] points = { new Point(0, 0), new Point(100, 50) };            // Draw line connecting two untransformed points.            e.Graphics.DrawLine(new Pen(Color.Blue, 3), points[0], points[1]);            // Set world transformation of Graphics object to translate.            e.Graphics.TranslateTransform(40, 30);            // Transform points in array from world to page coordinates.            e.Graphics.TransformPoints(CoordinateSpace.Page, CoordinateSpace.World, points);            // Reset world transformation.            e.Graphics.ResetTransform();            // Draw line that connects transformed points.            e.Graphics.DrawLine(new Pen(Color.Red, 3), points[0], points[1]); 5、选择参数：将此变换参数放在已有的变换矩阵之后还是之前。MatrixOrder.Append//MatrixOrder.Prepend  //----------------旋转和平移的顺序不一样，得到的结果页不一样。6、辅助功能 GraphicsState transState = e.Graphics.Save();//保存当前绘图板状态e.Graphics.ResetTransform();//重置e.Graphics.Restore(transState);//置为此状态