捕獲屏幕

Question

我試圖捕捉（截屏）的景色。爲此，我使用下面顯示的一段代碼將其保存到我的文檔目錄中作爲PNG圖像。

UIGraphicsBeginImageContextWithOptions(highlightViewController.fhView.centerView.frame.size, YES, 1.0); 
[self.view.layer renderInContext:UIGraphicsGetCurrentContext()]; 
UIImage *screenshot = UIGraphicsGetImageFromCurrentImageContext(); 
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); 
NSString *documentsDirectory = [paths objectAtIndex:0]; 
NSString *appFile = [documentsDirectory stringByAppendingPathComponent:@"1.png"]; 
NSData *imageData = UIImagePNGRepresentation(screenshot); 
[imageData writeToFile:appFile atomically:YES]; 
UIGraphicsEndImageContext(); 

問題：我可以捕獲部分視圖嗎？因爲在上面的代碼中，我無法更改原點（框架）。如果任何人有其他方法來捕捉視圖的特定部分，請分享它。

Answer 1

你可以裁切圖像： http://iosdevelopertips.com/graphics/how-to-crop-an-image.html

CGRect rect = CGRectMake(0,0,10,10); 
CGImageRef imageRef = CGImageCreateWithImageInRect([screenshot CGImage], rect); 
UIImage *croppedScreenshot = [UIImage imageWithCGImage:imageRef]; 
CGImageRelease(imageRef); 

Answer 2

看看你是否可以指定這樣的矩形，然後採取截圖。

CGRect requiredRect = CGRectMake(urView.frame.origin.x, urView.frame.origin.y, urView.bounds.size.width, urView.bounds.size.height); 
UIGraphicsBeginImageContext(requiredRect.size); 

您可以更改原點並查看它是否有效。 如果這個不奏效，你可以嘗試裁剪圖像由@mcb

Answer 3

試試這個代碼中提到。這肯定工作，因爲我已經在我的許多項目中實施它：

- (UIImage *)image 
{ 
    if (cachedImage == nil) { 
     //YOU CAN CHANGE THE FRAME HERE TO WHATEVER YOU WANT TO CAPTURE 
     CGRect imageFrame = CGRectMake(0, 0, 400, 300); 
     UIView *imageView = [[UIView alloc] initWithFrame:imageFrame]; 
     [imageView setOpaque:YES]; 
     [imageView setUserInteractionEnabled:NO]; 

     [self renderInView:imageView withTheme:nil];   

     UIGraphicsBeginImageContext(imageView.bounds.size); 
      CGContextRef c = UIGraphicsGetCurrentContext(); 
      CGContextGetCTM(c); 
      CGContextScaleCTM(c, 1, -1); 
      CGContextTranslateCTM(c, 0, -imageView.bounds.size.height); 
      [imageView.layer renderInContext:c]; 
      cachedImage = [UIGraphicsGetImageFromCurrentImageContext() retain]; 

      // rescale graph 
      UIImage* bigImage = UIGraphicsGetImageFromCurrentImageContext(); 
      CGImageRef scaledImage = [self newCGImageFromImage:[bigImage CGImage] scaledToSize:CGSizeMake(100.0f, 75.0f)]; 
      cachedImage = [[UIImage imageWithCGImage:scaledImage] retain]; 
      CGImageRelease(scaledImage); 
     UIGraphicsEndImageContext(); 

     [imageView release]; 
    } 

    return cachedImage; 
} 

我希望這會幫助你。

Answer 4

您可以使用此代碼

UIGraphicsBeginImageContext(self.view.bounds.size); 

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

UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext(); 
UIGraphicsEndImageContext(); 
CGRect rect; 
rect = CGRectMake(250,61 ,410, 255); 
CGImageRef imageRef = CGImageCreateWithImageInRect([viewImage CGImage], rect); 

UIImage *img = [UIImage imageWithCGImage:imageRef]; 

UIImageWriteToSavedPhotosAlbum(img, nil, nil, nil); 
CGImageRelease(imageRef);