iOS截图功能

-(UIImage *)captureScreenWithRect:(CGRect)rect{

UIGraphicsBeginImageContextWithOptions(self.view.bounds.size, YES, 1);

[self.view.layer renderInContext:UIGraphicsGetCurrentContext()];

UIImage *img = UIGraphicsGetImageFromCurrentImageContext();

UIImage *resultImg = [UIImage imageWithCGImage:CGImageCreateWithImageInRect(img.CGImage, rect)];

UIGraphicsEndImageContext();

return resultImg;

}