java GoogleAccountCredential getSelectedAccountName（）在设置并实现权限后返回null

Question

我正在使用联系人组的GET_ACCOUNTS权限，并在代码中进行处理。我就是不明白为什么设置后帐户名仍然为空。应用程序已经拥有权限，因为没有弹出对话框告诉用户授予权限

我在onCreate中设置凭据，如下所示：

        mCredential = GoogleAccountCredential.usingOAuth2(
                getApplicationContext(), Arrays.asList(SCOPES))
                .setBackOff(new ExponentialBackOff());

下面是我试图设置名称的地方：

/**
 * Attempts to set the account used with the API credentials. If an account
 * name was previously saved it will use that one; otherwise an account
 * picker dialog will be shown to the user. Note that the setting the
 * account to use with the credentials object requires the app to have the
 * GET_ACCOUNTS permission, which is requested here if it is not already
 * present. The AfterPermissionGranted annotation indicates that this
 * function will be rerun automatically whenever the GET_ACCOUNTS permission
 * is granted.
 */
@AfterPermissionGranted(REQUEST_PERMISSION_GET_ACCOUNTS)
    private void chooseAccount() {
        if (EasyPermissions.hasPermissions(
                this, Manifest.permission.GET_ACCOUNTS)) {

            String accountName = getPreferences(Context.MODE_PRIVATE)
                    .getString(PREF_ACCOUNT_NAME, null);
            if (accountName != null) {
                mCredential.setSelectedAccountName(accountName); // I set the account name here

                Log.d("MESSAGE", accountName); // this prints out the account name as an email
                Log.d("MESSAGE", mCredential.getSelectedAccountName()); // this throws a null pointer

                getResultsFromApi();
            } else {
                // Start a dialog from which the user can choose an account
                Log.d("MESSAGE", "Start dialogue box to select account");
                startActivityForResult(
                        mCredential.newChooseAccountIntent(),
                        REQUEST_ACCOUNT_PICKER);
            }
        } else {
            // Request the GET_ACCOUNTS permission via a user dialog
            Log.d("MESSAGE", "Creates dialogue box to request permission");
            EasyPermissions.requestPermissions(
                    this,
                    "This app needs to access your Google account (via Contacts).",
                    REQUEST_PERMISSION_GET_ACCOUNTS,
                    Manifest.permission.GET_ACCOUNTS);
        }
    }

以下是我对清单文件的权限：

    <uses-permission 安卓:name="安卓.permission.INTERNET" />
    <uses-permission 安卓:name="安卓.permission.ACCESS_NETWORK_STATE" />
    <uses-permission 安卓:name="安卓.permission.GET_ACCOUNTS" />

这是我的第一个项目，我不是很有经验。任何帮助都将不胜感激

Answer 1

我也有同样的问题。用户setSelectedAccount（）而不是setSelectedAccountName（）

 mCredential = GoogleAccountCredential.usingOAuth2(
                getApplicationContext(), Arrays.asList(SCOPES))
                .setBackOff(new ExponentialBackOff());

        // to set accountName manually instead of prompting user to select it
        mCredential.setSelectedAccount(new Account("xyz@gmail.com", "come.android.example"));

第一个参数是gmail帐户，第二个参数是包名。它应该会起作用