webview加载不出内容

1联网权限
2mWv.loadUrl(mUrl);一定要放在最后加载

public class MainActivity extends Activity {
    private ProgressBar mPb;
    private WebView mWv;
    private WebSettings mWebSettings;
    private String mUrl = "http://3g.163.com";


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initViews();
        initDatas();
    }

    private void initDatas() {
        webSettings();
        webView();
    }

    /**
     * webView的相关设置
     */
    private void webView() {
        //为了更好的支持表单
        mWv.setFocusable(true);
        mWv.setFocusableInTouchMode(true);
        mWv.requestFocus();
        mWv.setWebViewClient(new WebViewClient() {
            //目的是要让我们应用自己来加载网页，而不是交给浏览器
            @Override
            public boolean shouldOverrideUrlLoading(WebView view, String url) {
                view.loadUrl(url);
                return true;
            }
        });

        mWv.setWebChromeClient(new WebChromeClient() {
            @Override
            public void onProgressChanged(WebView view, int newProgress) {
                super.onProgressChanged(view, newProgress);
                mPb.setProgress(newProgress);
                mPb.setVisibility(newProgress == 100 ? GONE : VISIBLE);
            }
        });
        mWv.loadUrl(mUrl);
    }

    /**
     * web的相关设置
     */
    private void webSettings() {
        mWebSettings = mWv.getSettings();
        //让webview支持js
        mWebSettings.setJavaScriptEnabled(true);
        //设置是否支持缩放模式
        mWebSettings.setSupportZoom(true);
        mWebSettings.setBuiltInZoomControls(true);
        // 是否显示+ -
        mWebSettings.setDisplayZoomControls(false);
    }

    private void initViews() {
        mPb = (ProgressBar) findViewById(R.id.pb);
        mWv = (WebView) findViewById(R.id.wv);
    }

    /**
     * back键处理
     */
    @Override
    public void onBackPressed() {
        if (mWv.canGoBack()) mWv.goBack();
        else super.onBackPressed();
    }
}