iOS wkwebview和 uiwebview 内容图片自适应大小

- (void)webViewDidFinishLoad:(UIWebView *)webView {
//    2、都有效果
    NSString *js=@"var script = document.createElement('script');"
    "script.type = 'text/javascript';"
    "script.text = "function ResizeImages() { "
    "var myimg,oldwidth;"
    "var maxwidth = %f;"
    "for(i=0;i <document.images.length;i++){"
    "myimg = document.images[i];"
    "if(myimg.width > maxwidth){"
    "oldwidth = myimg.width;"
    "myimg.width = %f;"
    "}"
    "}"
    "}";"
    "document.getElementsByTagName('head')[0].appendChild(script);";
    js=[NSString stringWithFormat:js,[UIScreen mainScreen].bounds.size.width,[UIScreen mainScreen].bounds.size.width-15];
    [webView stringByEvaluatingJavaScriptFromString:js];
    [webView stringByEvaluatingJavaScriptFromString:@"ResizeImages();"];

}

wkwebview:

 NSString *jScript = @"var meta = document.createElement('meta'); meta.setAttribute('name', 'viewport'); meta.setAttribute('content', 'width=device-width'); document.getElementsByTagName('head')[0].appendChild(meta);";
    WKUserScript *wkUScript = [[WKUserScript alloc] initWithSource:jScript injectionTime:WKUserScriptInjectionTimeAtDocumentEnd forMainFrameOnly:YES];
    WKUserContentController *wkUController = [[WKUserContentController alloc] init];
    [wkUController addUserScript:wkUScript];
    WKWebViewConfiguration *wkWebConfig = [[WKWebViewConfiguration alloc] init];
    wkWebConfig.userContentController = wkUController;
    _myWeb = [[WKWebView alloc]initWithFrame:CGRectMake(0, kHeight(60), kGetWidth(self.view.bounds), kGetHeigh(self.view.bounds) - kHeight(70)) configuration:wkWebConfig];