iOS 开发_UIImage添加水印和Logo

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1.应用场景：

Paste_Image.png

2.实现目标：

应项目要求，有些时候我们需要对图片进行打水印、加Logo的操作，在原始图片的基础上重新绘制出有文字水印和Logo之后的图片

3.代码说明：

/**  根据需要打入水印的图片和文字，重新返回绘制结束后的新的图片*/
/**  waterImage:打入水印的图片，即为 如来 */
/**  waterString:打入水印的文字，即为"致敬经典" */
- (UIImage *)yp_getNewImageWithOriginalImage:(UIImage *)originalImage  waterImage:(UIImage *)waterImage waterString:(NSString *)waterString  {

    UIGraphicsBeginImageContext(originalImage.size);
    
    // 原始图片渲染
    [originalImage drawInRect:CGRectMake(0, 0, originalImage.size.width, originalImage.size.height)];
    
    CGFloat waterX = originalImage.size.width - 200;
    CGFloat waterY = originalImage.size.height - 200;
    CGFloat waterW = 200;
    CGFloat waterH = 200;
    
    // 打入的水印图片 渲染
    [waterImage drawInRect:CGRectMake(waterX, waterY, waterW, waterH)];
    
    // 打入的水印的文字渲 染
    NSMutableParagraphStyle * paragraphStyle = [[NSMutableParagraphStyle defaultParagraphStyle] mutableCopy];
    
    paragraphStyle.lineBreakMode = NSLineBreakByCharWrapping;
    
    NSDictionary * dic = @{
                           NSFontAttributeName : [UIFont systemFontOfSize:40],
                           NSParagraphStyleAttributeName : paragraphStyle,
                           NSForegroundColorAttributeName : [UIColor redColor]
                           };
    
    [waterString drawInRect:CGRectMake(50, 50, 200, 50) withAttributes:dic];
    
    UIGraphicsEndPDFContext();
    
    // UIImage
    UIImage * imageNew = UIGraphicsGetImageFromCurrentImageContext();
    
    return imageNew;
}

//使用方式
UIImage * originalImage  = [UIImage imageNamed:@"wukong"];
UIImage * waterImage = [UIImage imageNamed:@"rulai"];
UIImage *newImage = [self yp_getNewImageWithOriginalImage:originalImage  waterImage:waterImage waterString:waterString ]
self.imageView.image = newImage;