iOS: 计算 UIWebView 的内容高度

- (void)webViewDidFinishLoad:(UIWebView *)wb
{
//方法1
CGFloat 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2
CGRect 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;
}