保存/恢复android webview的状态

我有一个简单的webView应用程序,它从我们的网站加载一个页面,其中包含我们的现场人员应该每天访问的位置和电话号码.它提供了启动导航或拨打电话的钩子.从外部活动返回时,应用程序崩溃.点击手机的主页按钮,然后拨打手机,然后返回到应用程序工作正常.

这是代码……

更新2 – 不再崩溃,返回时webview为空

public class VSIMobile_WebView extends Activity {
private static String PROVIDER="gps";
private WebView browser;
private LocationManager myLocationManager=null;
private TelephonyManager myTeleManager = null;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    getWindow().setFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON, WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
    browser=(WebView)findViewById(R.id.webview);
    myLocationManager=(LocationManager)getSystemService(Context.LOCATION_SERVICE);
    myTeleManager=(TelephonyManager)getSystemService(Context.TELEPHONY_SERVICE);
    browser.getSettings().setJavaScriptEnabled(true);
    browser.addJavascriptInterface(new Locater(), "locater");
    browser.addJavascriptInterface(new JavaScriptInterface(this), "Android");
    if (savedInstanceState!=null){
        browser.restoreState(savedInstanceState);
    }else{ 
        browser.loadUrl("http://zzz.com");
        browser.setWebViewClient(new HelloWebViewClient());
    }
}

public void onConfigurationChanged(Configuration newConfig) {
    super.onConfigurationChanged(newConfig);
    }

@Override
public void onSaveInstanceState(Bundle outState) {
    //Toast.makeText(getBaseContext(), browser.getUrl(), Toast.LENGTH_LONG).show();
    browser.saveState(outState);
} 

@Override
protected void onRestoreInstanceState(Bundle state) {
    browser.restoreState(state);
    super.onRestoreInstanceState(state);
    //Toast.makeText(getBaseContext(), browser.getUrl(), Toast.LENGTH_LONG).show();
}


/* Did not work
public void onResume(Bundle inState){
    browser.restoreState(inState);
    super.onResume();   
}
public void onPause(Bundle outState) {
    browser.saveState(outState);
    super.onPause();
}
*/


@Override
public void onResume(){
    super.onResume();   
}


@Override
public void onPause() {
    super.onPause();
}