Android AccountManager和登录活动

Question

我使用AccountManager在我的应用程序中验证用户

我知道我可以调用getAuthTokenByFeatures,如果没有为我的特定accountType设置帐户,它会启动我的LoginActivity,这正是我想要的,

我有一个BaseActivity,它在onCreate方法上执行,但是在启动LoginActivity时,旧活动仍然在堆栈上,因此通过按后退按钮,用户可以返回到上一个活动是我不想要的行为,我在BaseActibity.onCreate上的代码如下

    AccountManager manager = AccountManager.get(getBaseContext());

    manager.getAuthTokenByFeatures(
            AccountGeneral.ACCOUNT_TYPE,
            AccountGeneral.AUTHTOKEN_TYPE_FULL_ACCESS,
            null,
            this,
            null,
            null,
            new AccountManagerCallback<Bundle>() {
                @Override
                public void run(AccountManagerFuture<Bundle> future) {
                    Bundle bnd = null;
                    try {
                        bnd = future.getResult();
                        final String authtoken = bnd.getString(AccountManager.KEY_AUTHTOKEN);

                        LOGV(TAG, "GetTokenForAccount Bundle is " + bnd);

                    } catch (Exception e) {
                        LOGE(TAG, "exception while getAuthTokenByFeatures", e);
                    }
                }
            }
            , null);

问题是:如何禁用该返回行为？如果是我以编程方式调用LoginActivity,我只需在BaseActivity上调用finish()

Answer 1

在您的AccountAuthenticatorActivity上,您可以覆盖后退按钮行为:

@Override
public void onBackPressed() {
    Intent result = new Intent();
    Bundle b = new Bundle();
    result.putExtras(b);

    setAccountAuthenticatorResult(null); // null means the user cancelled the authorization processs
    setResult(RESULT_OK, result);
    finish();
}

现在您可以对此取消做出反应.在你的代码中:

            @Override
            public void run(AccountManagerFuture<Bundle> future) {
                Bundle bnd = null;
                try {
                    if (future.isCancelled()) {
                        // Do whatever you want. I understand that you want to close this activity,
                        // so supposing that mActivity is your activity:
                        mActivity.finish();
                        return;
                    }
                    bnd = future.getResult();

                    final String authtoken = bnd.getString(AccountManager.KEY_AUTHTOKEN);

                    LOGV(TAG, "GetTokenForAccount Bundle is " + bnd);

                } catch (Exception e) {
                    LOGE(TAG, "exception while getAuthTokenByFeatures", e);
                }
            }