Jonathan Jonathan - 4 months ago 50
Objective-C Question

How to create an image from UILabel?

I'm currently developing a simple photoshop like application on iphone. When I want to flatten my layers, the labels are at the good position but with a bad font size.
Here's my code to flatten :

UIGraphicsBeginImageContext(CGSizeMake(widthDocument,widthDocument));

for (UILabel *label in arrayLabel) {
[label drawTextInRect:label.frame];
}

UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();


Anybody can help me ?

Answer

From: pulling an UIImage from a UITextView or UILabel gives white image.

// iOS

- (UIImage *)grabImage {
    // Create a "canvas" (image context) to draw in.
    UIGraphicsBeginImageContextWithOptions(self.bounds.size, self.opaque, 0.0);  // high res
    // Make the CALayer to draw in our "canvas".
    [[self layer] renderInContext: UIGraphicsGetCurrentContext()];

    // Fetch an UIImage of our "canvas".
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();

    // Stop the "canvas" from accepting any input.
    UIGraphicsEndImageContext();

    // Return the image.
    return image;
}

// Swift extension w/ usage. credit @Heberti Almeida in below comments

extension UIImage {
    class func imageWithLabel(label: UILabel) -> UIImage {
        UIGraphicsBeginImageContextWithOptions(label.bounds.size, false, 0.0)
        label.layer.renderInContext(UIGraphicsGetCurrentContext()!)
        let img = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return img
    }
}

The usage:

let label = UILabel(frame: CGRect(x: 0, y: 0, width: 30, height: 22))
label.text = bulletString
let image = UIImage.imageWithLabel(label)
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