How to capture UIView to UIImage without loss of q

Question

My code works fine for normal devices but creates blurry images on retina devices.

Does anybody know a solution for my issue?

+ (UIImage *) imageWithView:(UIView *)view
{
    UIGraphicsBeginImageContext(view.bounds.size);
    [view.layer renderInContext:UIGraphicsGetCurrentContext()];

    UIImage * img = UIGraphicsGetImageFromCurrentImageContext();

    UIGraphicsEndImageContext();

    return img;
}

Answer 1

In this method just pass a view object and it will returns a UIImage object.

-(UIImage*)getUIImageFromView:(UIView*)yourView
{
 UIGraphicsBeginImageContext(yourView.bounds.size);
 [yourView.layer renderInContext:UIGraphicsGetCurrentContext()];
 UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
 UIGraphicsEndImageContext();
 return image;
}

Answer 2

Switch from use of UIGraphicsBeginImageContext to UIGraphicsBeginImageContextWithOptions (as documented on this page). Pass 0.0 for scale (the third argument) and you'll get a context with a scale factor equal to that of the screen.

UIGraphicsBeginImageContext uses a fixed scale factor of 1.0, so you're actually getting exactly the same image on an iPhone 4 as on the other iPhones. I'll bet either the iPhone 4 is applying a filter when you implicitly scale it up or just your brain is picking up on it being less sharp than everything around it.

So, I guess:

#import <QuartzCore/QuartzCore.h>

+ (UIImage *)imageWithView:(UIView *)view
{
    UIGraphicsBeginImageContextWithOptions(view.bounds.size, view.opaque, 0.0);
    [view.layer renderInContext:UIGraphicsGetCurrentContext()];

    UIImage * img = UIGraphicsGetImageFromCurrentImageContext();

    UIGraphicsEndImageContext();

    return img;
}

And in swift 4:

func image(with view: UIView) -> UIImage? {
    UIGraphicsBeginImageContextWithOptions(view.bounds.size, view.isOpaque, 0.0)
    defer { UIGraphicsEndImageContext() }
    if let context = UIGraphicsGetCurrentContext() {
        view.layer.render(in: context)
        let image = UIGraphicsGetImageFromCurrentImageContext()
        return image
    }
    return nil
}

Answer 3

Some times drawRect Method makes problem so I got these answers more appropriate. You too may have a look on it Capture UIImage of UIView stuck in DrawRect method

Answer 4

All Swift 3 answers did not worked for me so I have translated the most accepted answer:

extension UIImage {
    class func imageWithView(view: UIView) -> UIImage {
        UIGraphicsBeginImageContextWithOptions(view.bounds.size, view.isOpaque, 0.0)
        view.layer.render(in: UIGraphicsGetCurrentContext()!)
        let img: UIImage? = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return img!
    }
}

Answer 5

Using modern UIGraphicsImageRenderer

public extension UIView {
    @available(iOS 10.0, *)
    public func renderToImage(afterScreenUpdates: Bool = false) -> UIImage {
        let rendererFormat = UIGraphicsImageRendererFormat.default()
        rendererFormat.opaque = isOpaque
        let renderer = UIGraphicsImageRenderer(size: bounds.size, format: rendererFormat)

        let snapshotImage = renderer.image { _ in
            drawHierarchy(in: bounds, afterScreenUpdates: afterScreenUpdates)
        }
        return snapshotImage
    }
}

Answer 6

Swift 2.0:

Using extension method:

extension UIImage{

   class func renderUIViewToImage(viewToBeRendered:UIView?) -> UIImage
   {
       UIGraphicsBeginImageContextWithOptions((viewToBeRendered?.bounds.size)!, false, 0.0)
       viewToBeRendered!.drawViewHierarchyInRect(viewToBeRendered!.bounds, afterScreenUpdates: true)
       viewToBeRendered!.layer.renderInContext(UIGraphicsGetCurrentContext()!)

       let finalImage = UIGraphicsGetImageFromCurrentImageContext()
       UIGraphicsEndImageContext()

       return finalImage
   }

}

Usage:

override func viewDidLoad() {
    super.viewDidLoad()

    //Sample View To Self.view
    let sampleView = UIView(frame: CGRectMake(100,100,200,200))
    sampleView.backgroundColor =  UIColor(patternImage: UIImage(named: "ic_120x120")!)
    self.view.addSubview(sampleView)    

    //ImageView With Image
    let sampleImageView = UIImageView(frame: CGRectMake(100,400,200,200))

    //sampleView is rendered to sampleImage
    var sampleImage = UIImage.renderUIViewToImage(sampleView)

    sampleImageView.image = sampleImage
    self.view.addSubview(sampleImageView)

 }