iPhone: Create a screenshot programmatically and then add it as a subview - iphone

Question

I would like to call a method which takes a screenshot and then load this screenshot as a subview. I am using Apples sample code on how to take a screen shot (see below) and was trying to use the result (an image) in my code. However, I don't really know how to get the image from the method into my code. This is what I tried; it's obviously wrong, but it's all I could come up with:
// Test Screenshot:
screenShot = [UIImage screenshot]; // THIS DOESN'T WORK
screenShotView = [[UIImageView alloc] initWithImage:screenShot];
[screenShotView setFrame:CGRectMake(0, 0, 320, 480)];
[self.view addSubview:screenShotView];
And this is Apple's sample code for the method:
- (UIImage*)screenshot
{
NSLog(#"Shot");
// Create a graphics context with the target size
// On iOS 4 and later, use UIGraphicsBeginImageContextWithOptions to take the scale into consideration
// On iOS prior to 4, fall back to use UIGraphicsBeginImageContext
CGSize imageSize = [[UIScreen mainScreen] bounds].size;
if (NULL != UIGraphicsBeginImageContextWithOptions)
UIGraphicsBeginImageContextWithOptions(imageSize, NO, 0);
else
UIGraphicsBeginImageContext(imageSize);
CGContextRef context = UIGraphicsGetCurrentContext();
// Iterate over every window from back to front
for (UIWindow *window in [[UIApplication sharedApplication] windows])
{
if (![window respondsToSelector:#selector(screen)] || [window screen] == [UIScreen mainScreen])
{
// -renderInContext: renders in the coordinate space of the layer,
// so we must first apply the layer's geometry to the graphics context
CGContextSaveGState(context);
// Center the context around the window's anchor point
CGContextTranslateCTM(context, [window center].x, [window center].y);
// Apply the window's transform about the anchor point
CGContextConcatCTM(context, [window transform]);
// Offset by the portion of the bounds left of and above the anchor point
CGContextTranslateCTM(context,
-[window bounds].size.width * [[window layer] anchorPoint].x,
-[window bounds].size.height * [[window layer] anchorPoint].y);
// Render the layer hierarchy to the current context
[[window layer] renderInContext:context];
// Restore the context
CGContextRestoreGState(context);
}
}
// Retrieve the screenshot image
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return image;
}
Any help would be very much appreciated! Thanks.
EDIT: This is the viewDidLoad method in which I create a TextView and then try to capture a screen shot of it:
- (void)viewDidLoad {
// Setup TextView:
NSString* someText = #"Some Text";
CGRect frameText = CGRectMake(0, 0, 320, 480);
aTextView = [[UITextView alloc] initWithFrame:frameText];
aTextView.text = someText;
[self.view addSubview:aTextView];
// Test Screenshot:
screenShotView = [[UIImageView alloc] initWithImage:[self screenshot]];
[screenShotView setFrame:CGRectMake(10, 10, 200, 200)];
[self.view addSubview:screenShotView];
[self.view bringSubviewToFront:screenShotView];
[super viewDidLoad];
}

Answer 1

To use the image just change this line
screenShot = [UIImage screenshot];
To
screenShot = [self screenshot];
Edit: Check to see if the [self screenshot] returns a valid image or nil.
- (void)viewDidLoad {
// Setup TextView:
NSString* someText = #"Some Text";
CGRect frameText = CGRectMake(0, 0, 320, 480);
aTextView = [[UITextView alloc] initWithFrame:frameText];
aTextView.text = someText;
[self.view addSubview:aTextView];
// Test Screenshot:
UIImage *screenShotImage = [self screenShot];
if(screenShot){
screenShotView = [[UIImageView alloc] initWithImage:screenShotImage];
[screenShotView setFrame:CGRectMake(10, 10, 200, 200)];
[self.view addSubview:screenShotView];
[self.view bringSubviewToFront:screenShotView];
}else
NSLog(#"Something went wrong in screenShot method, the image is nil");
[super viewDidLoad];
}