捕获屏幕

我正试图捕捉（屏幕截图）一个视图。 为此，我使用下面显示的一段代码将其保存到我的文档目录中作为PNG图像。

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(); 

问题：我可以捕捉部分视图吗？ 因为在上面的代码我不能改变原点（框架）。 如果有人有其他方法来捕捉某个特定的部分，请分享。

Answer 1

你可以裁剪图像： 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

试试这个代码。 这肯定工作，因为我已经在我的许多项目中实现它：

 - (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; } 

我希望这能帮到您。

Answer 3

看看你是否可以像这样指定矩形，然后截图。

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

你可以改变原点，看看它是否有效。 如果不能解决问题，您可以尝试按@mcb所述修剪图像

Answer 4

你可以使用这个代码

 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);