第一种方式：

-(UIImage *)watermarkImage:(UIImage *)img withName:(NSString *)name

{

NSString* mark = name;

intw = img.size.width;

inth = img.size.height;

UIGraphicsBeginImageContext(img.size);

[img drawInRect:CGRectMake(, , w, h)];

NSDictionary *attr = @{

NSFontAttributeName: [UIFont boldSystemFontOfSize:],//设置字体

NSForegroundColorAttributeName : [UIColor redColor]//设置字体颜色

};

[mark drawInRect:CGRectMake(, , , ) withAttributes:attr];//左上角

[mark drawInRect:CGRectMake(w - , , , ) withAttributes:attr];//右上角

[mark drawInRect:CGRectMake(w - , h - - , , ) withAttributes:attr];//右下角

[mark drawInRect:CGRectMake(, h - - , , ) withAttributes:attr];//左下角

UIImage *aimg = UIGraphicsGetImageFromCurrentImageContext();

UIGraphicsEndImageContext();

returnaimg;

}

第二种方式：

// 画水印

- (UIImage *) imageWithWaterMask:(UIImage*)mask inRect:(CGRect)rect

{

#if __IPHONE_OS_VERSION_MAX_ALLOWED >= 40000

if([[[UIDevice currentDevice] systemVersion] floatValue] >= 4.0)

{

UIGraphicsBeginImageContextWithOptions([self size], NO, 0.0);// 0.0 for scale means "scale for device's main screen".

}

#else

if([[[UIDevice currentDevice] systemVersion] floatValue] < 4.0)

{

UIGraphicsBeginImageContext([self size]);

}

#endif

//原图

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

//水印图

[mask drawInRect:rect];

UIImage *newPic = UIGraphicsGetImageFromCurrentImageContext();

UIGraphicsEndImageContext();

returnnewPic;

}