iOS获取webView的内容高度

- (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);
}