- (void)webViewDidFinishLoad:(UIWebView *)webView
{
    //字体大小
    [webView stringByEvaluatingJavaScriptFromString:@"document.getElementsByTagName('body')[0].style.webkitTextSizeAdjust= '200%'"];
    //字体颜色
    [webView stringByEvaluatingJavaScriptFromString:@"document.getElementsByTagName('body')[0].style.webkitTextFillColor= 'green'"];
    //页面背景色
    [webView stringByEvaluatingJavaScriptFromString:@"document.getElementsByTagName('body')[0].style.background='#ffffff'"];
}