重新回到LoginActivity 清空所有栈
1. 相当于重启app
Intent intent = new Intent(this, LoginActivity.class);
ComponentName cn = intent.getComponent();
Intent mainIntent = IntentCompat.makeRestartActivityTask(cn);
startActivity(mainIntent);
2.
Intent intent = new Intent();
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK |
Intent.FLAG_ACTIVITY_CLEAR_TASK);
intent.setClass(mContext, LoginActivity.class);
mContext.startActivity(intent);