How to Draw Text in Center to Uiimage

how to draw text in center to uiimage?

Try this:

func textToImage(drawText text: NSString, inImage image: UIImage) -> UIImage? {
    //draw image first
    UIGraphicsBeginImageContext(image.size)
    image.draw(in: CGRect(x: 0, y: 0, width: image.size.width, height: image.size.height))
    
    //text attributes
    let font=UIFont(name: "Helvetica-Bold", size: 32)!
    let text_style=NSMutableParagraphStyle()
    text_style.alignment=NSTextAlignment.center
    let text_color=UIColor.white
    let attributes=[NSFontAttributeName:font, NSParagraphStyleAttributeName:text_style, NSForegroundColorAttributeName:text_color]

    //vertically center (depending on font)
    let text_h=font.lineHeight
    let text_y=(image.size.height-text_h)/2
    let text_rect=CGRect(x: 0, y: text_y, width: image.size.width, height: text_h)
    text.draw(in: text_rect.integral, withAttributes: attributes)
    let result=UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()
    return result
}

How to make text appear in centre of the image?

Added to @osteven answer. Below code works as I expected. Hope it helps others.

 func textToImage(drawText: NSString, inImage: UIImage, atPoint:CGPoint)->UIImage{

// Setup the font specific variables
var textColor: UIColor = UIColor.redColor()
var textFont: UIFont =  UIFont(name: "AmericanTypewriter", size: 75)!
let textStyle  = NSTextEffectLetterpressStyle

//Setup the image context using the passed image.
UIGraphicsBeginImageContext(inImage.size)

let textFontAttributes = [
    NSFontAttributeName: textFont,
    NSForegroundColorAttributeName: textColor,
    NSTextEffectAttributeName : textStyle
]

inImage.drawInRect(CGRectMake(0, 0, inImage.size.width, inImage.size.height))

 let textSize = drawText.sizeWithAttributes(textFontAttributes)
    if textSize.width < inImage.size.width {
        println("lesser")
        let textRect = CGRectMake(inImage.size.width / 2 - textSize.width / 2, 0,
        inImage.size.width / 2 + textSize.width / 2, inImage.size.height - textSize.height)
        drawText.drawInRect(textRect, withAttributes: textFontAttributes)
    }
    else {
        println("greater")
        let textRect = CGRectMake(0 , 0,
            inImage.size.width, inImage.size.height)
        drawText.drawInRect(textRect, withAttributes: textFontAttributes)

    }

var newImage: UIImage = UIGraphicsGetImageFromCurrentImageContext()

UIGraphicsEndImageContext()
return newImage

How to set text on uiimage center?

Try this:

UIGraphicsBeginImageContext(targetSize);
NSString *txt = @"my String";
UIColor *txtColor = [UIColor whiteColor];
UIFont *txtFont = [UIFont systemFontOfSize:30];
NSDictionary *attributes = @{NSFontAttributeName:txtFont, NSForegroundColorAttributeName:txtColor};

CGRect txtRect = [txt boundingRectWithSize:CGSizeZero
                                   options:NSStringDrawingUsesLineFragmentOrigin
                                attributes:attributes
                                   context:nil];

[txt drawAtPoint:CGPointMake(targetSize.width/2 - txtRect.size.width/2, targetSize.height/2 - txtRect.size.height/2) withAttributes:attributes];
UIImage *resultImg = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

How do I use the NSString draw functionality to create a UIImage from text

You can try this: (updated for iOS 4)

-(UIImage *)imageFromText:(NSString *)text
{
    // set the font type and size
    UIFont *font = [UIFont systemFontOfSize:20.0];  
    CGSize size  = [text sizeWithFont:font];

    // check if UIGraphicsBeginImageContextWithOptions is available (iOS is 4.0+)
    if (UIGraphicsBeginImageContextWithOptions != NULL)
        UIGraphicsBeginImageContextWithOptions(size,NO,0.0);
    else
        // iOS is < 4.0 
        UIGraphicsBeginImageContext(size);

    // optional: add a shadow, to avoid clipping the shadow you should make the context size bigger 
    //
    // CGContextRef ctx = UIGraphicsGetCurrentContext();
    // CGContextSetShadowWithColor(ctx, CGSizeMake(1.0, 1.0), 5.0, [[UIColor grayColor] CGColor]);

    // draw in context, you can use also drawInRect:withFont:
    [text drawAtPoint:CGPointMake(0.0, 0.0) withFont:font];

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

    return image;
}

To call it:

UIImage *image = [self imageFromText:@"This is a text"];

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

Draw text inside an image and return the resulting image:

+(UIImage*) drawText:(NSString*) text 
             inImage:(UIImage*)  image 
             atPoint:(CGPoint)   point 
{

    UIFont *font = [UIFont boldSystemFontOfSize:12];
    UIGraphicsBeginImageContext(image.size);
    [image drawInRect:CGRectMake(0,0,image.size.width,image.size.height)];
    CGRect rect = CGRectMake(point.x, point.y, image.size.width, image.size.height);
    [[UIColor whiteColor] set];
    [text drawInRect:CGRectIntegral(rect) withFont:font]; 
    UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    return newImage;
}

Usage:

// note: replace "ImageUtils" with the class where you pasted the method above
UIImage *img = [ImageUtils drawText:@"Some text"
                            inImage:img 
                            atPoint:CGPointMake(0, 0)];

Change the origin of the text inside the image from 0,0 to whatever point you like.

To paint a rectangle of solid color behind the text, add the following before the line [[UIColor whiteColor] set];:

[[UIColor brownColor] set];
CGContextFillRect(UIGraphicsGetCurrentContext(), 
                  CGRectMake(0, (image.size.height-[text sizeWithFont:font].height), 
                                  image.size.width, image.size.height));

I'm using the text size to calculate the origin for the solid color rectangle, but you can replace it with any number.

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