问显示进度对话框并允许更改屏幕方向的登录屏幕

EN

<application
        android:allowBackup="true"
        android:configChanges="orientation|keyboardHidden|screenSize"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme">
        <activity
            android:name=".activities.MainActivity"
            android:configChanges="orientation|keyboardHidden|screenSize"
            android:label="@string/app_name"/>

    @Override
    public void onConfigurationChanged(Configuration newConfig) {
        super.onConfigurationChanged(newConfig);
        Log.v(this.getClass().getName(), "onConfigurationChanged()");
    }

private ProgressDialog pDialog;

private class MyAsync extends AsyncTask<String, Void, String> {
    Activity context;

    public MyAsync (Activity context) {
        this.context = context;
    }

    @Override
    protected void onPreExecute(){ 
        super.onPreExecute();
        pdia = new ProgressDialog(context);
        pdia.setMessage("Loading...");
        pdia.show();    
    }
    @Override
    protected String doInBackground(String... urls) {
        ...
        //do your login scheme
        ...
        //context.methods()
        return "ok";
    }
    @Override
    protected void onPostExecute(String result) {
        pDialog.dismiss();
        if(result!=null && result.equals("ok")){
            //login was successfully done
        } else {
            //login has failed
        }
    }
}

new MyAsync(this).execute(null, null , null);