计算 webView 显示内容后实际高度

两种方法，方法1可以得到内容的实际高度，方法2得到了将内容显示完整后的 webView 的尺寸（包含 UIEdgeInsets）

- (void)webViewDidFinishLoad:(UIWebView *)wb{//方法1CGFloat documentWidth = [[wb stringByEvaluatingJavaScriptFromString:@"document.getElementById('content').offsetWidth"] floatValue];CGFloat documentHeight = [[wb stringByEvaluatingJavaScriptFromString:@"document.getElementById("content").offsetHeight;"] floatValue];NSLog(@"documentSize = {%f, %f}", documentWidth, documentHeight);//方法2CGRect frame = wb.frame;frame.size.width = 768;frame.size.height = 1;//    wb.scrollView.scrollEnabled = NO;wb.frame = frame;frame.size.height = wb.scrollView.contentSize.height;NSLog(@"frame = %@", [NSValue valueWithCGRect:frame]);wb.frame = frame;}