Add watermark text to the iOS image (watermark text on the image on Weibo)

Build a category (do not know how to build can go to Baidu a bit) uiimage category

class purpose. h file file name is Uiimage+watermark

#import <UIKit/UIKit.h>

@interface UIImage (Watermark)

Define a method

-(UIImage *) Watermarkimage: (nsstring *) text;

@end

Implementation of the. m file

#import "Uiimage+watermark.h"

@implementation UIImage (Watermark)

-(UIImage *) Watermarkimage: (nsstring *) text{

//1. Get Context

uigraphicsbeginimagecontext(self. size );

//2. Drawing Pictures

[selfdrawinrect:cgrectmake(0,0, self. Size. width,self. size. height)];

//3. Draw Watermark Text

cgrect rect = cgrectmake(0,self. Size. height-self. size. width,a);

nsmutableparagraphstyle *style = [[nsmutableparagraphstyleDefaultparagraphstyle ]mutablecopy];

style. Alignment = Nstextalignmentcenter;

// properties of text

nsdictionary *dic = @{

nsfontattributename: [uifontsystemfontofsize:],

nsparagraphstyleattributename: Style,

nsforegroundcolorattributename: [uicolorwhitecolor]

};

// draw the text up

[Text drawinrect: Rectwithattributes:d ic];

//4. get the picture you're drawing

UIImage *watermarkimage =uigraphicsgetimagefromcurrentimagecontext();

//5. end drawing of a picture

uigraphicsendimagecontext();

return watermarkimage;

}

@end

Then add a Uiimageview import class (Uiimage+watermark) file to the Viewcontroller view

#import "ViewController.h"

#import "Uiimage+watermark.h"

@interface viewcontroller ()

@end

@implementation Viewcontroller

-(void) Viewdidload {

[superviewdidload];

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

Invoke class Intent method implementation function

UIImage *img = [Image watermarkimage:@ "@ white "];

uiimageview *imageview = [[uiimageviewalloc] initwithimage: img];

Imageview.frame = Self.view.bounds;

[Self. View addsubview: ImageView];

}

-(void) didreceivememorywarning {

[superdidreceivememorywarning];

//Dispose of any resources, can be recreated.

}

@end

Add watermark Text to iOS images (watermark text on Weibo)