捕捉屏幕的射門從0,0

Question

開始我使用下面的代碼，使屏幕快照

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，但它返回的全屏幕，和我想要一個特定幀的屏幕截圖像
(100,100,200,200)，我試圖讓在

UIGraphicsBeginImageContext(self.view.frame.size); 

的變化，但沒有成功

請幫助。

Answer 1

試試這個：

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(); 

Answer 2

只使用三個行代碼。

UIGraphicsBeginImageContext(CGSizeMake(320, 480)); 
    [self.window.layer renderInContext:UIGraphicsGetCurrentContext()]; 
    UIImage *frame= UIGraphicsGetImageFromCurrentImageContext();