UIWebView 實作自适應高度

UIWebView加載本地html檔案，要做到自适應高度，以滿足視圖其他控件對它的位置的依賴，比如webView 下面還有兩個button, button的frame要根據webView的實際高度來計算，實作方法即可以調用webView代理方法， 有以下4種方法：

方法1：擷取webview中scrovllview的contentsize進行設定

#pragma mark - webView Delegate

-(void)webViewDidFinishLoad:(UIWebView*)webView{

    //capture the contentSize of WebView, and reset self.myWebView frame

    CGFloat webViewHeight = [webView.scrollView contentSize].height;

    CGRect newFrame = webView.frame;

    newFrame.size.height = webViewHeight;

    webView.frame = newFrame;

}

方法2：執行js語句 直接擷取html文檔的dom高度

-(void)webViewDidFinishLoad:(UIWebView*)webView{

    CGFloat webViewHeight=

    [[webView stringByEvaluatingJavaScriptFromString: @"document.body.offsetHeight"]floatValue];

    // CGFloat webViewHeight= [[webView stringByEvaluatingJavaScriptFromString:@"document.body.scrollHeight"]floatValue];

    CGRect newFrame = webView.frame;

    newFrame.size.height = webViewHeight;

    webView.frame = newFrame;

}

//方法3.先将UIWebView的高度設為最小，然後再使用sizeThatFits就會傳回剛好合适的大小

-(void)webViewDidFinishLoad:(UIWebView*)webView{

    CGSize actualSize =[webView sizeThatFits:CGSizeZero];

    CGRect newFrame = webView.frame;

    newFrame.size.height = actualSize.height;

    webView.frame = newFrame;

}

//方法4.周遊webview子視圖 擷取UIWebDocumentView高度即實際高度

-(void)webViewDidFinishLoad:(UIWebView*)webView{

 CGFloat webViewHeight = 0.0f;

    if([webView.subviews count] > 0){

        UIView *scrollerView = webView.subviews[0];

        if([scrollerView.subviews count]>0){

            UIView *webDocView = scrollerView.subviews.lastObject;

               if([webDocView isKindOfClass:[NSClassFromString(@"UIWebDocumentView")class]])

            {

              webViewHeight = webDocView.frame.size.height;//擷取文檔的高度

                webView.frame = webDocView.frame;

                //更新UIWebView 的高度

            }

        }

    }

}