问如何在WebView中加载外部网页

EN

import android.app.Activity;
import android.os.Bundle;
import android.webkit.WebResourceError;
import android.webkit.WebResourceRequest;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.Toast;
import android.annotation.TargetApi;

public class Main extends Activity {

    private WebView mWebview ;

    @Override
    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        mWebview  = new WebView(this);

        mWebview.getSettings().setJavaScriptEnabled(true); // enable javascript

        final Activity activity = this;

        mWebview.setWebViewClient(new WebViewClient() {
            @SuppressWarnings("deprecation")
            @Override
            public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) {
                Toast.makeText(activity, description, Toast.LENGTH_SHORT).show();
            }
            @TargetApi(android.os.Build.VERSION_CODES.M)
            @Override
            public void onReceivedError(WebView view, WebResourceRequest req, WebResourceError rerr) {
                // Redirect to deprecated method, so you can use it in all SDK versions
                onReceivedError(view, rerr.getErrorCode(), rerr.getDescription().toString(), req.getUrl().toString());
            }
        });

        mWebview .loadUrl("http://www.google.com");
        setContentView(mWebview );

    }

}

public class WebViewController extends WebViewClient {
    @Override
    public boolean shouldOverrideUrlLoading(WebView view, String url) {
        view.loadUrl(url);
        return true;
    }
}
webView.setWebViewClient(new WebViewController());

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="fill_parent"
    android:layout_height="fill_parent" android:background="@drawable/background">
    <RelativeLayout android:layout_width="fill_parent"
        android:layout_height="wrap_content" android:background="@drawable/top_heading"
        android:id="@+id/rlayout1">
        <TextView android:layout_width="wrap_content"
            android:layout_centerVertical="true" android:layout_centerHorizontal="true"
            android:textColor="#ffffff" android:textSize="22dip"
            android:textStyle="bold" android:layout_height="wrap_content"
            android:text="More Information" android:id="@+id/txtviewfbdisplaytitle" />
    </RelativeLayout>
    <RelativeLayout android:layout_width="fill_parent"
        android:layout_height="fill_parent" android:layout_below="@+id/rlayout1"
        android:id="@+id/rlayout2">
        <WebView android:id="@+id/webview1" android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            android:layout_weight="1.0" />
    </RelativeLayout>
</RelativeLayout>

public class MainActivity extends Activity {
    private class MyWebViewClient extends WebViewClient {
          @Override
          public boolean shouldOverrideUrlLoading(WebView view, String url) {
              view.loadUrl(url);
              return true;
          }
    }
    Button btnBack;
    WebView webview;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        webview=(WebView)findViewById(R.id.webview1);
        webview.setWebViewClient(new MyWebViewClient());
        openURL();
    }

     /** Opens the URL in a browser */
    private void openURL() {
        webview.loadUrl("http://www.google.com");
        webview.requestFocus();
    }
}