Add watermark text on IOS images (watermark text on images on Weibo)

Add watermark text on IOS images (watermark text on Weibo)

 

Create a category (you can go to Baidu if you don't know how to create it ).

Class Object. h file name: UIImage + watermark

 

# Import

 

@ Interface UIImage (watermark)

// Define a method

-(UIImage *) watermarkImage :( NSString *) text;

@ End

. M file implementation

 

# Import "UIImage + watermark. h"

 

@ Implementation UIImage (watermark)

-(UIImage *) watermarkImage :( NSString *) text {

 

// 1. Obtain the context

UIGraphicsBeginImageContext (self. size );

 

// 2. Draw an image

[Self drawInRect: CGRectMake (0, 0, self. size. width, self. size. height)];

 

// 3. Draw watermark text

CGRect rect = CGRectMake (0, self. size. height-20, self. size. width, 20 );

 

NSMutableParagraphStyle * style = [[NSMutableParagraphStyle defaultParagraphStyle] mutableCopy];

Style. alignment = NSTextAlignmentCenter;

// Text attributes

NSDictionary * dic = @{

NSFontAttributeName: [UIFont systemFontOfSize: 13],

NSParagraphStyleAttributeName: style,

NSForegroundColorAttributeName: [UIColor whiteColor]

};

// Draw the text

[Text drawInRect: rect withAttributes: dic];

 

// 4. Obtain the drawn Image

UIImage * watermarkImage = UIGraphicsGetImageFromCurrentImageContext ();

 

// 5. Draw the ending Image

UIGraphicsEndImageContext ();

 

Return watermarkImage;

}

@ End

Then add a UIImageView import category (UIImage + watermark) file to the viewController view.

 

# Import "ViewController. h"

# Import "UIImage + watermark. h"

@ Interface ViewController ()

 

@ End

 

@ Implementation ViewController

 

-(Void) viewDidLoad {

[Super viewDidLoad];

 

 

UIImage * image = [UIImage imageNamed: @ "baymax.jpg"];

 

// Call the objective method implementation function

UIImage * img = [image watermarkImage: @ "@ "];

 

UIImageView * imageView = [[UIImageView alloc] initWithImage: img];

// ImageView. frame = self. view. bounds;

 

[Self. view addSubview: imageView];

}

 

-(Void) didReceiveMemoryWarning {

[Super didReceiveMemoryWarning];

// Dispose of any resources that can be recreated.

}

 

@ End