iOS webview注入JS

- (void)webViewDidFinishLoad:(UIWebView *)webView {
  NSString *js = @"function imgAutoFit() {      var imgs = document.getElementsByTagName(‘img‘);      for (var i = 0; i < imgs.length; ++i) {        var img = imgs[i];           img.style.maxWidth = %f;        }   }";
  js = [NSString stringWithFormat:js, [UIScreen mainScreen].bounds.size.width - 20];
 
  [webView stringByEvaluatingJavaScriptFromString:js];
  [webView stringByEvaluatingJavaScriptFromString:@"imgAutoFit()"];
}