WebView 高度计算

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

CGRect newFrame = webView.frame;

newFrame.size.height= webViewHeight;

webView.frame= newFrame;

CGSize actualSize = [webView sizeThatFits:CGSizeZero];

CGRect newFrame = webView.frame;

newFrame.size.height = actualSize.height;

webView.frame = newFrame;


_webView.scalesPageToFit = YES;