WinForm Picture Rotation

01.//可以实现任意角度的旋转，旋转出现的角落空白可以选择填充的颜色。

02.  03.  04. using  System; 05.  06. using  System.Drawing; 07. using  System.Drawing.Drawing2D; 08. using  System.Drawing.Imaging; 09. using  System.Text; 10. using  System.Windows.Forms; 11.  12. namespace  bitmaprerote 13. { 14. public  partial  class  Form1 : Form 15. { 16. public  Form1() 17. { 18. InitializeComponent(); 19. } 20. public  static  Bitmap KiRotate(Bitmap bmp,  float  angle, Color bkColor) 21. { 22. int  w = bmp.Width + 2; 23. int  h = bmp.Height + 2; 24.  25. PixelFormat pf; 26.  27. if  (bkColor == Color.Transparent) 28. { 29. pf = PixelFormat.Format32bppArgb; 30. } 31. else 32. { 33. pf = bmp.PixelFormat; 34. } 35.  36. Bitmap tmp =  new  Bitmap(w, h, pf); 37. Graphics g = Graphics.FromImage(tmp); 38. g.Clear(bkColor); 39. g.DrawImageUnscaled(bmp, 1, 1); 40. g.Dispose(); 41.  42. GraphicsPath path =  new  GraphicsPath(); 43. path.AddRectangle( new  RectangleF(0f, 0f, w, h)); 44. Matrix mtrx =  new  Matrix(); 45. mtrx.Rotate(angle); 46. RectangleF rct = path.GetBounds(mtrx); 47.  48. Bitmap dst =  new  Bitmap(( int )rct.Width, ( int )rct.Height, pf); 49. g = Graphics.FromImage(dst); 50. g.Clear(bkColor); 51. g.TranslateTransform(-rct.X, -rct.Y); 52. g.RotateTransform(angle); 53. g.InterpolationMode = InterpolationMode.HighQualityBilinear; 54. g.DrawImageUnscaled(tmp, 0, 0); 55. g.Dispose(); 56. tmp.Dispose(); 57. return  dst; 58. } 59. private  void  button2_Click( object  sender, EventArgs e) 60. { 61. Bitmap map =  new  Bitmap( "F:\\hj.jpg" ); 62. this .pictureBox1.SizeMode = PictureBoxSizeMode.StretchImage; 63. map = KiRotate(map, 30, Color.Pink); 64. pictureBox1.Image = map; 65. } 66. } 67. }

WinForm Picture Rotation