How to write text on image in Objective-C (iOS)?

Question

I want to make an image like this programmatically:

I have the upper image and text with me. Should I write text on the image?

I want to make it a complete .png image(image + label) and set it as the background of the button.

Answer 1

Swift 3 version of @Hossam Ghareebs answer and added the missing integration of the backgroundColor parameter:

enum WaterMarkCorner{
    case TopLeft
    case TopRight
    case BottomLeft
    case BottomRight
}

extension UIImage{

    func waterMarkedImage(_ waterMarkText:String, corner:WaterMarkCorner = .TopRight, margin:CGPoint = CGPoint(x: 20, y: 20), waterMarkTextColor:UIColor = UIColor.black, waterMarkTextFont:UIFont = UIFont.systemFont(ofSize: 40), backgroundColor:UIColor = UIColor(white: 1.0, alpha: 0.5)) -> UIImage?{

        let textAttributes = [NSForegroundColorAttributeName:waterMarkTextColor, NSFontAttributeName:waterMarkTextFont, NSBackgroundColorAttributeName: backgroundColor]
        let textSize = NSString(string: waterMarkText).size(attributes: textAttributes)
        var textFrame = CGRect(x:0, y:0, width:textSize.width, height:textSize.height)

        let imageSize = self.size
        switch corner{
        case .TopLeft:
            textFrame.origin = margin
        case .TopRight:
            textFrame.origin = CGPoint(x: imageSize.width - textSize.width - margin.x, y: margin.y)
        case .BottomLeft:
            textFrame.origin = CGPoint(x: margin.x, y: imageSize.height - textSize.height - margin.y)
        case .BottomRight:
            textFrame.origin = CGPoint(x: imageSize.width - textSize.width - margin.x, y: imageSize.height - textSize.height - margin.y)
        }

        /// Start creating the image with water mark
        UIGraphicsBeginImageContext(imageSize)
        self.draw(in: CGRect(x:0, y:0, width:imageSize.width, height:imageSize.height))

        NSString(string: waterMarkText).draw(in: textFrame, withAttributes: textAttributes)

        let waterMarkedImage = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()

        return waterMarkedImage
    }
}

Answer 2

Use this method to add your textfield on image with selected font and color and size

//Method to add 
- (UIImage *) addText:(UIImage *)img text:(NSString *)text
{
    CGRect rect =  CGRectMake(0,0, img.size.width, img.size.height);

    // create a context according to image size
    UIGraphicsBeginImageContext(rect.size);

    // draw image
    [img drawInRect:rect];


    float fontSize = _txtvwEdit.font.pointSize*2;
    NSLog(@"Original %f new %f",_txtvwEdit.font.pointSize,fontSize);

    UIFont* font = [UIFont fontWithName:_txtvwEdit.font.fontName size:fontSize];

    CGRect textRect = CGRectMake((_txtvwEdit.frame.origin.x*2)-5,_txtvwEdit.frame.origin.y*2,_txtvwEdit.frame.size.width*2,_txtvwEdit.frame.size.height*2);

    if ([temparyGifframes count]>0)
    {
        font = [UIFont fontWithName:_txtvwEdit.font.fontName size:_txtvwEdit.font.pointSize];

        textRect =    CGRectMake(_txtvwEdit.frame.origin.x,_txtvwEdit.frame.origin.y ,_txtvwEdit.frame.size.width,_txtvwEdit.frame.size.height);

    }

    /// Make a copy of the default paragraph style
    NSMutableParagraphStyle* paragraphStyle = [[NSParagraphStyle defaultParagraphStyle] mutableCopy];
    paragraphStyle.lineBreakMode = NSLineBreakByCharWrapping;
    paragraphStyle.alignment = NSTextAlignmentLeft;

    NSDictionary *attributes = @{ NSFontAttributeName: font, NSForegroundColorAttributeName: _txtvwEdit.textColor,NSParagraphStyleAttributeName: paragraphStyle };

    // draw text
    [text drawInRect:textRect withAttributes:attributes];


    // get as image
    UIImage * image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    return image; 
}