UIWebView获得内容的高－作出自适应高的UIWebView

- (void)webViewDidFinishLoad:(UIWebView *)webView{    NSString *height_str= [webView stringByEvaluatingJavaScriptFromString: @"document.body.offsetHeight"];    int height = [height_str intValue];    webView.frame = CGRectMake(0,0,320,height);    NSLog(@"height: %@", [webView stringByEvaluatingJavaScriptFromString: @"document.body.offsetHeight"]);}