互联网与网站有哪些/搜索优化seo
现在有两张图片,如下:
+
如何为上面这张图片打上 CSDN 的logo图片呢?实现如下效果:
废话少说,上代码:
/* 为一张图片打上水印 */
// 参数说明
// baName : 背景图片名称
// logoName : logo图片名称
+ (instancetype)waterImageWithBg:(NSString *)bgName logo:(NSString *)logoName
{UIImage *bgImage = [UIImage imageNamed:bgName];// 创建并开启一个基于位图的上下文UIGraphicsBeginImageContextWithOptions(bgImage.size, NO, 0.0);// 画背景[bgImage drawInRect:CGRectMake(0, 0, bgImage.size.width, bgImage.size.height)];// 画左下角的水印UIImage *logoImage = [UIImage imageNamed:logoName];CGFloat scale = 0.5;CGFloat margin = 10;CGFloat logoW = logoImage.size.width * scale;CGFloat logoH = logoImage.size.height * scale;CGFloat logoX = bgImage.size.width - logoW - margin;CGFloat logoY = bgImage.size.height - logoH - margin;[logoImage drawInRect:CGRectMake(logoX, logoY, logoW, logoH)];// 从上下文中取得制作完毕的UIImage对象UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();// 结束上下文UIGraphicsEndImageContext();return newImage;
}
总结:同样的,我们可以将其分装到UIImage的category中,方便项目中的调用:-D