Android Web视图显示白屏

Android webview显示白屏而不是在Android 4.1.2上加载网站.当我从网页浏览器打开它时,网站完全打开,我使用下面的代码

public class MainActivity extends AppCompatActivity {
WebView web;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    web = (WebView) findViewById(R.id.webview);
    web.setWebViewClient(new myWebClient());
    web.getSettings().setJavaScriptEnabled(true);
    web.loadUrl("www.Example.com");
}

public class myWebClient extends WebViewClient
{
    @Override
    public void onPageStarted(WebView view, String url, Bitmap favicon) {
        // TODO Auto-generated method stub
        super.onPageStarted(view, url, favicon);
    }

    @Override
    public boolean shouldOverrideUrlLoading(WebView view, String url) {
        // TODO Auto-generated method stub

        view.loadUrl(url);
        return true;

    }
}

// To handle "Back" key press event for WebView to go back to previous screen.
@Override
public boolean onKeyDown(int keyCode, KeyEvent event)
{
    if ((keyCode == KeyEvent.KEYCODE_BACK) && web.canGoBack()) {
        web.goBack();
        return true;
    }
    return super.onKeyDown(keyCode, event);
}

}

记得设置协议"http:"

 web.loadUrl("http://www.Example.com");

非常重要的是,请确保url在此时具有值:

  @Override
    public boolean shouldOverrideUrlLoading(WebView view, String url) {
        view.loadUrl(url);
        return true;

    }