从0,0开始捕获屏幕截图

Question

我正在使用以下代码进行屏幕截图

UIGraphicsBeginImageContext(self.view.frame.size);

blendMode:kCGBlendModeClear alpha:1.0];

[self.view.window.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
UIImageWriteToSavedPhotosAlbum(viewImage, nil, nil, nil);

return viewImage;

它工作正常,但它返回全屏,我想要一个特定帧的屏幕截图,比如( 100,100,200,200),我试图进行更改:

UIGraphicsBeginImageContext(self.view.frame.size);

但没有成功.

Answer 1

试试这个:

float x = 100;
float y = 100;
CGSize size = CGSizeMake(200,200);

UIGraphicsBeginImageContext(size);
CGContextRef c = UIGraphicsGetCurrentContext();
CGContextTranslateCTM(c, -x, -y);
[view.layer renderInContext:c];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();