How to Take a Screenshot Programmatically on Ios

How to take a screenshot programmatically on iOS

I'm answering this question as it's a highly viewed, and there are many answers out there plus there's Swift and Obj-C.

Disclaimer This is not my code, nor my answers, this is only to help people that land here find a quick answer. There are links to the original answers to give credit where credit is due!! Please honor the original answers with a +1 if you use their answer!

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Using QuartzCore

#import <QuartzCore/QuartzCore.h> 

if ([[UIScreen mainScreen] respondsToSelector:@selector(scale)]) {
    UIGraphicsBeginImageContextWithOptions(self.window.bounds.size, NO, [UIScreen mainScreen].scale);
} else {
    UIGraphicsBeginImageContext(self.window.bounds.size);
}

[self.window.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
NSData *imageData = UIImagePNGRepresentation(image);
if (imageData) {
    [imageData writeToFile:@"screenshot.png" atomically:YES];
} else {
    NSLog(@"error while taking screenshot");
}

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In Swift

func captureScreen() -> UIImage
{

    UIGraphicsBeginImageContextWithOptions(self.view.bounds.size, false, 0);

    self.view.drawViewHierarchyInRect(view.bounds, afterScreenUpdates: true)

    let image: UIImage = UIGraphicsGetImageFromCurrentImageContext()

    UIGraphicsEndImageContext()

    return image
}

Note: As the nature with programming, updates may need to be done so please edit or let me know! *Also if I failed to include an answer/method worth including feel free to let me know as well!

Screenshot on swift programmatically

If you have some sort of Objective-C knowledge then here is the answer that you want.

Open this Link and follow the last answer which iterates through all the view hierarchy and And have line by line comments to fully understand the code.

The Image is finally converted into both NSData and UIImage.
If you are still confuse then i can convert it into swift but first try it by your self.

Here is the Swift code of that Answer.

func screenshot() -> UIImage {
    let imageSize = UIScreen.main.bounds.size as CGSize;
    UIGraphicsBeginImageContextWithOptions(imageSize, false, 0)
    let context = UIGraphicsGetCurrentContext()
    for obj : AnyObject in UIApplication.shared.windows {
        if let window = obj as? UIWindow {
            if window.responds(to: #selector(getter: UIWindow.screen)) || window.screen == UIScreen.main {
                                // so we must first apply the layer's geometry to the graphics context
                                context!.saveGState();
                                // Center the context around the window's anchor point
                                context!.translateBy(x: window.center.x, y: window.center
                                    .y);
                                // Apply the window's transform about the anchor point
                                context!.concatenate(window.transform);
                                // Offset by the portion of the bounds left of and above the anchor point
                context!.translateBy(x: -window.bounds.size.width * window.layer.anchorPoint.x,
                                     y: -window.bounds.size.height * window.layer.anchorPoint.y);

                                // Render the layer hierarchy to the current context
                                window.layer.render(in: context!)

                                // Restore the context
                                context!.restoreGState();
            }
        }
    }
    let image = UIGraphicsGetImageFromCurrentImageContext();
    return image!
}

how to take a screenshot of the iPhone programmatically?

You need to create a bitmap context of the size of your screen and use

[self.view.layer renderInContext:c]

to copy your view in it. Once this is done, you can use

CGBitmapContextCreateImage(c)

to create a CGImage from your context.

Elaboration :

CGSize screenSize = [[UIScreen mainScreen] applicationFrame].size;
CGColorSpaceRef colorSpaceRef = CGColorSpaceCreateDeviceRGB(); 
CGContextRef ctx = CGBitmapContextCreate(nil, screenSize.width, screenSize.height, 8, 4*(int)screenSize.width, colorSpaceRef, kCGImageAlphaPremultipliedLast);
CGContextTranslateCTM(ctx, 0.0, screenSize.height);
CGContextScaleCTM(ctx, 1.0, -1.0);

[(CALayer*)self.view.layer renderInContext:ctx];

CGImageRef cgImage = CGBitmapContextCreateImage(ctx);
UIImage *image = [UIImage imageWithCGImage:cgImage];
CGImageRelease(cgImage);
CGContextRelease(ctx);  
[UIImageJPEGRepresentation(image, 1.0) writeToFile:@"screen.jpg" atomically:NO];

Note that if you run your code in response to a click on a UIButton, your image will shows that button pressed.

Take screenshot from camera view

To solve this issue, I'had to switch the video call camera from back to front camera so that user could user the back camera to take photo, once he done with taking photo I switch back the video call to back camera.

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