UIGraphicsBeginImageContext如何設置位置？

Question

我在我的應用程序中截圖。我可以截取屏幕截圖，但現在我想通過指定x和y座標來獲取屏幕截圖。我的意思是從y = 40開始截圖。那可能嗎？

UIGraphicsBeginImageContext(screenshot.frame.size); 
[self.view.layer renderInContext:UIGraphicsGetCurrentContext()]; 
UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext(); 
UIGraphicsEndImageContext(); 

Answer 1

UIGraphicsBeginImageContext(screenshot.frame.size); 
CGImageRef imageRef = CGImageCreateWithImageInRect((CGImageRef)self.view.layer.contents, cropRect); 
UIImage *image = [UIImage imageWithCGImage:imageRef]; 
CGImageRelease(imageRef); 
[image drawInRect:CGRectMake(...)]; 
UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext(); 
UIGraphicsEndImageContext();