问当有Wi-Fi连接时，在loginActivity中启动loginActivity

EN

Intent loginActivity = new Intent(this, LoginActivity.class);
startActivity(loginActivity);

 protected void onActivityResult(int requestCode, int resultCode,
             Intent data)

public class TestProjectActivity extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    // Register for Wifi state changes.
    this.registerReceiver(wifiChangedReceiver, new IntentFilter(
            WifiManager.WIFI_STATE_CHANGED_ACTION));
}

// BroadcastReceiver that will get notified when the Wifi state changes.
private BroadcastReceiver wifiChangedReceiver = new BroadcastReceiver() {
    @Override
    public void onReceive(Context arg0, Intent arg1) {
        int extraWifiState = arg1.getIntExtra(WifiManager.EXTRA_WIFI_STATE,
                WifiManager.WIFI_STATE_UNKNOWN);

        // No need to listen for all the states, but it might be interesting
        // at a later point ;)
        switch (extraWifiState) {
        case WifiManager.WIFI_STATE_DISABLED:
            showToast("Wifi disabled...");
            break;
        case WifiManager.WIFI_STATE_DISABLING:
            showToast("Wifi disabling...");
            break;
        case WifiManager.WIFI_STATE_ENABLED:
            showToast("Wifi enabled...");
            break;
        case WifiManager.WIFI_STATE_ENABLING:
            showToast("Wifi enabling...");
            break;
        default:
            break;
        }
    }
};

// Instead of showing a toast, you could launch a new activity.
private void showToast(String action) {
    Toast.makeText(this, action, Toast.LENGTH_LONG).show();
}

// When leaving the activity that has registered for a broadcast, remember
// to unregister the broadcast or you'll get an exception at some point.
@Override
protected void onStop() {
    super.onStop();
    this.unregisterReceiver(wifiChangedReceiver);
    }
}