How to take a screenshot programmatically in iOS? - iphone

Question

I have a UIView that uses both UIKit control and OpenGL. I'd like to get a screenshot of that view programatically.
If I use UIGraphicsGetImageFromCurrentImageContext(), the OpenGL content is blank;
If I use the glReadPixels(...) method, the UIKit content is blank;
I'm confused as how to take a complete screenshot.
Thank you!

Answer 1

use following code to take screen shot
-(UIImage *) screenshot
{
CGRect rect;
rect=CGRectMake(0, 0, 320, 480);
UIGraphicsBeginImageContext(rect.size);
CGContextRef context=UIGraphicsGetCurrentContext();
[self.view.layer renderInContext:context];
UIImage *image=UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return image;
}

Answer 2

-(UIImage *) screenshot
{
CGImageRef UIGetScreenImage(void);
CGImageRef screen = UIGetScreenImage();
UIImage* screenImage = [UIImage imageWithCGImage:screen];
CGImageRelease(screen); // you need to call this.
return screenImage;
}

Answer 3

Well, there are few ways of capturing the iPhone screen programmatically
Using UIKIT http://developer.apple.com/library/ios/#qa/qa1703/_index.html
Using AVFoundation framework http://developer.apple.com/library/ios/#qa/qa1702/_index.html
Using OpenGL ES
http://developer.apple.com/library/ios/#qa/qa1704/_index.html
Starting from iOS 7 you can also use Why does my programmatically created screenshot look so bad on iOS 7?
Using UIWindow
CGRect screenRect = [[UIScreen mainScreen] bounds];
UIGraphicsBeginImageContext(screenRect.size);
CGContextRef ctx = UIGraphicsGetCurrentContext();
[[UIColor blackColor] set];
CGContextFillRect(ctx, screenRect);
[self.window.layer renderInContext:ctx];
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
Using UIView
UIGraphicsBeginImageContext(self.view.frame.size);
[self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *viImage=UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
Out of these 6 options, I found the first option very convenient for copy-pasting and for applying level of compression as 1st method gives the image with true pixel data. I also like option 4, as the API comes with SDK.

Answer 4

You get result Uiimage without lose quality of image
- (UIImage *)captureView:(UIView *)view {
UIGraphicsBeginImageContextWithOptions(view.bounds.size, view.opaque, 0.0);
[view.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage * img = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return img;
}

Answer 5

UIGraphicsBeginImageContext(self.view.bounds.size);
[self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
NSData *data = [UIImagePNGRepresentation(image) retain];
UImage *screenShot = [UIImage imageWithData:data];

Answer 6

You know where the OpenGL content is located in your view. So it should be easy to copy the result of glReadPixels into the snapshot of the UIKit.

Answer 7

maybe.. can you use something from here
- https://stackoverflow.com/questions/12413460/cocos2d-2-0-screenshots-on-ios-6
and here...
Why is glReadPixels() failing in this code in iOS 6.0?

Answer 8

Here is how you can take a simple screenshot programmatically of a UIImage. If you want it for any other object substitute the UIImage with it.
In the .h file add NSData *Data; then in your .m file add this to your code
UIGraphicsBeginImageContext(self.view.frame.size);
[self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *attachimage = [[UIImage alloc]initWithData:Data];
UIImage *viImage=UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
attachimage = viImage;
UIImageWriteToSavedPhotosAlbum(viImage, nil, nil, nil);