iphone开发webview 修改所有相应tag背景

[webViewstringByEvaluatingJavaScriptFromString:

@"var script = document.createElement('script');"

"script.type = 'text/javascript';"

"script.text = \"function ResetTextBgColor() { "

"var links = document.getElementsByTagName('p');"

"for (var i=0;i<links.length;i++) {"

"links[i].style.backgroundColor= 'red';"

"};"

"}\";"

"document.getElementsByTagName('head')[0].appendChild(script);"];

[webViewstringByEvaluatingJavaScriptFromString:@"ResetTextBgColor();"];