How to take a screenshot programmatically in iOS?

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!

score 8 · Answer 1 · answered Dec 05 '12 at 12:16

8

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;
     }

answered Dec 05 '12 at 12:16

Himanshu Mahajan

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1

This code is just for take UIKit stuff...The question is more complex and well explained: he need to take also OpenGL stuff. – Matteo Gobbi May 19 '14 at 15:04

score 5 · Answer 2 · edited May 23 '17 at 12:24

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.

Thanks for this, it seems that screens with sub-view controllers don't auto-add child view controller layers. But using the window seems to work for a full-screen image. Thanks! — slycrel, Sep 18 '13 at 20:00

score 5 · Answer 3 · answered Sep 05 '13 at 08:27

5

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

answered Sep 05 '13 at 08:27

Mann

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Can someone explain how it works? Also need to fix the orientation – ZYiOS Oct 07 '13 at 15:54
definitely not the way to go [this is why](http://stackoverflow.com/questions/3767860/uigetscreenimage-the-app-is-not-getting-the-approval-due-to-this-method) – Julian Sep 29 '15 at 12:24

score 2 · Answer 4 · answered Nov 08 '12 at 07:37

2

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;
     }

answered Nov 08 '12 at 07:37

kb920

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it doesn't take effects in an OpenGL page – coodi8 Nov 08 '12 at 07:58

score 1 · Answer 5 · answered Nov 08 '12 at 07:45

1

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

answered Nov 08 '12 at 07:45

Rushi

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it only take effects in UIKit condition, for OpenGL page, only get blank image – coodi8 Nov 08 '12 at 08:00

score 0 · Answer 6 · edited May 26 '16 at 07:19

0

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);

edited May 26 '16 at 07:19

Mahendra

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answered Nov 08 '12 at 07:32

IronManGill

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it only take effects in UIKit condition, for OpenGL page, only get blank image – coodi8 Nov 08 '12 at 08:01

score 0 · Answer 7 · answered Nov 08 '12 at 08:05

0

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.

answered Nov 08 '12 at 08:05

Felix K.

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I'm developing a screenshot control, I don't know whether the view is implemented by UIKit or OpenGL, or mixed. If I can get the info that the view is implemented by what, the problem will be solved. – coodi8 Nov 08 '12 at 08:12
@coodi8 I think this could be a problem. Won't be easy because OpenGL renders directly on the graphic chip. UI-Graphics are not rendered on the graphics chip. ( AFAIK ) – Felix K. Nov 08 '12 at 08:29

score 0 · Answer 8 · edited May 23 '17 at 12:16

0

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?

edited May 23 '17 at 12:16

Community

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answered Nov 08 '12 at 14:04

TonyMkenu

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How to take a screenshot programmatically in iOS?

8 Answers8