iOS 获取UIWebView的高度

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

CGFloat height = [[webView stringByEvaluatingJavaScriptFromString:@"document.body.offsetHeight"] floatValue];

CGRect frame = webView.frame;

webView.frame = CGRectMake(frame.origin.x, frame.origin.y, frame.size.width, height);

}