WebView加载网页无法弹出对话框

两步解决问题:

第一:

mWebView.setWebChromeClient(new WebChromeClient());

第二:

mWebView.setWebViewClient(new WebViewClient() {
    @Override
    public boolean shouldOverrideUrlLoading(WebView view, String url) {

        mWebView.setWebChromeClient(new WebChromeClient());
        view.loadUrl(url);
        return true;
    }
});