iOS WebView加载图片严重拉伸变形，解决方案很简单，让图片比例拉伸就好。

//在webView加载完毕后注入js样式修改图片宽高，网上很多人抄来抄去都只是更改了宽度，却没有去更改高度

-(void)webViewDidFinishLoad:(UIWebView *)webView{

    NSString *js = @"function changeImgWH() { \

    var imgs = document.getElementsByTagName('img'); \

    for (var i = 0; i < imgs.length; ++i) {\

    var img = imgs[i];\

    var imgW = img.width;\

    var imgH = img.height;\

    var s = imgH/imgW;\

    img.style.maxWidth = %f;\

    img.height = img.width*s; \

    } \

    }";

    js = [NSString stringWithFormat:js,  [UIScreen mainScreen].bounds.size.width - 15];

    [webView stringByEvaluatingJavaScriptFromString:js];

    [webView stringByEvaluatingJavaScriptFromString:@"changeImgWH()"];

}