iPhone剪切技巧

iPhone中的剪切技巧:
1.获取图形上下文
2.构造剪切的路径(形状)

3.构建剪切区域 
4.贴上你的画

 

 

// 1
CGContextRef context = UIGraphicsGetCurrentContext();

// 2
CGRect bounds = CGRectMake(0.0f, 0.0f, SIDELENGTH, SIDELENGTH);
CGMutablePathRef path = CGPathCreateMutable();
CGPathAddEllipseInRect(path, NULL, bounds);

// 3
CGContextAddPath(context, path);
CGContextClip(context);

// 4
[LOGO drawInRect:bounds];