@Override
 protected void onCreate(Bundle savedInstanceState) {
   super.onCreate(savedInstanceState);
   // 去除系统标题
   this.requestWindowFeature(Window.FEATURE_NO_TITLE);
   Log.d(TAG, "BaseActivity onCreate Invoke...");
   ManagerActivity.getInstance().addActivity(this);
 }
 @Override
 public void onBackPressed() {
   super.onBackPressed();
   Log.d(TAG, "BaseActivity onBackPressed Invoke...");
   ManagerActivity.getInstance().removeActivity(this);
 }