iOS图片上加标签或者水印

直接贴代码吧

UIImage+Text.h

#import <UIKit/UIKit.h>

@interface UIImage (Text)

- (UIImage*)addText:(NSString*)text1
               XPos:(int)xpos
               YPos:(int)ypos
           fontName:(NSString*)fontName
           fontSize:(CGFloat)fontSize
          fontColor:(UIColor*)fontColor;

@end

　　UIImage+Text.m

#import "UIImage+Text.h"

@implementation UIImage (Text)

- (UIImage*)addText:(NSString*)text1
               XPos:(int)xpos
               YPos:(int)ypos
           fontName:(NSString*)fontName
           fontSize:(CGFloat)fontSize
          fontColor:(UIColor*)fontColor {

    int w = self.size.width;
    int h = self.size.height;

    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
    CGContextRef context = CGBitmapContextCreate(NULL, w, h, 8, 4 * w, colorSpace, kCGImageAlphaPremultipliedFirst);

    CGContextDrawImage(context, CGRectMake(0, 0, w, h), self.CGImage);
    CGContextSetRGBFillColor(context, 0.0, 0.0, 1.0, 1);

    char *txt = (char*)[text1 cStringUsingEncoding:NSUTF8StringEncoding];
    char *font = (char*)[fontName cStringUsingEncoding:NSUTF8StringEncoding];

    CGContextSelectFont(context, font, fontSize, kCGEncodingMacRoman);
    CGContextSetTextDrawingMode(context, kCGTextFill);
    CGContextSetFillColorWithColor(context, fontColor.CGColor);
    CGContextShowTextAtPoint(context, xpos, ypos, txt, strlen(txt));

	CGImageRef imageRef = CGBitmapContextCreateImage(context);
	CGContextSetAllowsAntialiasing(context, YES);

	UIImage *result = [UIImage imageWithCGImage:imageRef];

	CGImageRelease(imageRef);
    CGContextRelease(context);
    CGColorSpaceRelease(colorSpace);

    return result;
}

@end

　调用举例

 UIImage *img = [UIImage imageNamed:@"image.jpg"];
    image.image = [img addText:text.text
                          XPos:80
                          YPos:300
                      fontName:@"Georgia-Bold"
                      fontSize:46.0
                     fontColor:[UIColor whiteColor]];