How to take a screenshot using code on iOS?

Question

How to take a screenshot programmatically?

Answer 1

You can use UIGraphicsBeginImageContext for this purpose.

For example :

UIGraphicsBeginImageContextWithOptions(self.view.bounds.size, self.view.opaque, 0.0);
[self.myView.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage*theImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

NSData*theImageData = UIImageJPEGRepresentation(theImage, 1.0 ); //you can use PNG too
[theImageData writeToFile:@"example.jpeg" atomically:YES];

Here

1. First i take the image context, i've given it as myView which is a webview, you can give whatever you wish for. This takes the image of webview that can be seen on the screen.

2 Using UIGraphicsGetImageFromCurrentImageContext() i convert the screenshot of my webview into an image.

3. By using UIGraphicsEndImageContext() i ask it end the context.

4. I'm saving the image into an NSData because i had to mail the screenshot. And keep it in NSData seemed a good option if it is used to send or save.

EDIT: To add it to the camera roll you need to write:

UIImageWriteToSavedPhotosAlbum(theImage,nil,NULL,NULL); after UIGraphicsEndImageContext();

Answer 2

Have a look at this answer.It also takes care of retina display.

Actually to explain the process,

• Choose a image context size (probably the layer size for which you need screen shot)
• Render the layer which you want to take screenshot in the created context
• Obtain the image from the context and you are done!