Android EditText setError() 无法按预期工作

我有问题setError() on EditText。当活动打开时，它会检查某些字段是否为空，如果为空，则在其上设置错误消息。但是，只有当我在字段中写入一些文本然后将其删除时，才会显示感叹号图标。如果我失去对该字段的关注，该图标将再次消失。两个领域Naam and Telefonnumer有这个验证。

我使用 Android 2.2.2 SDK，该应用程序在具有最新更新的 Nexus 7 上运行。

我有 Util 类：

public class Util {

    private static String TAG = "Util Class";

    public static boolean editTextIsEmpty(EditText edittext) {
        if (edittext.getText().toString().trim().length() < 1)
            return true;
        else
            return false;
    }

    public void editTextListener(final EditText editText) {
        editText.addTextChangedListener(new TextWatcher() {

            @Override
            public void afterTextChanged(Editable s) {
                // TODO Auto-generated method stub
            }

            @Override
            public void beforeTextChanged(CharSequence s, int start, int count, int after) {
                if (editTextIsEmpty(editText) && editText.isEnabled())
                    editText.setError("Nodig");
                else
                    editText.setError(null);
            }

            @Override
            public void onTextChanged(CharSequence s, int start, int before, int count) {
                if (editTextIsEmpty(editText) && editText.isEnabled())
                    editText.setError("Nodig");
                else
                    editText.setError(null);
            }
        });
    }
}

然后我有方法validateInput()在我的活动中：

public class DeliveryActivity extends BaseActivity {

    private ImageButton btnSetDate;

    private Button btnToSummary;
    private Button btnSearchAddress;

    private EditText txtPostcode;
    private EditText txtHouseNumber;
    private EditText txtHouseNumberSuffix;
    private EditText txtStreet;
    private EditText txtCity;
    private EditText txtDeliveryDate;
    private EditText txtName;
    private EditText txtPhone;
    private EditText txtEmail;
    private EditText txtRemark;

    private TextView lblExtraDeliveryInfo;

    private Spinner spinnerDelivery;
    private Spinner spinnerDeliveryPeriod;
    private Spinner spinnerContact;
    private Spinner spinnerDeliveryAddress;
    private Spinner spinnerExtraDeliveryInfo;

    private RelativeLayout rlDeliveryAddressDetails;

    private DevRestHelper additionalDeliveryInfo;
    private DevRestHelper searchClientAddress;

    private Util util = new Util();

    private int year;
    private int month;
    private int day;

    public static final int DIALOG_DATEPICKER = 0;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_delivery);

        initControls();

        validateInput();
    }

    private void initControls() {
        btnSetDate = (ImageButton) findViewById(R.id.activity_delivery_btnCalendar);

        btnToSummary = (Button) findViewById(R.id.activity_delivery_btnSummary);
        btnSearchAddress = (Button) findViewById(R.id.activity_delivery_btnSearchAddress);

        spinnerDelivery = (Spinner) findViewById(R.id.activity_delivery_spinnerDeliveryMethod);
        spinnerDeliveryPeriod = (Spinner) findViewById(R.id.activity_delivery_spinnerDeliveryPeriod);
        spinnerContact = (Spinner) findViewById(R.id.activity_delivery_spinnerContactperson);
        spinnerDeliveryAddress = (Spinner) findViewById(R.id.activity_delivery_spinnerDeliveryAddress);
        spinnerExtraDeliveryInfo = (Spinner) findViewById(R.id.activity_delivery_spinnerExtraDeliveryInformation);

        txtPostcode = (EditText) findViewById(R.id.activity_delivery_txtPostcode);
        txtHouseNumber = (EditText) findViewById(R.id.activity_delivery_txtHousenumber);
        txtHouseNumberSuffix = (EditText) findViewById(R.id.activity_delivery_txtHousenumberSuffix);
        txtStreet = (EditText) findViewById(R.id.activity_delivery_txtStreet);
        txtCity = (EditText) findViewById(R.id.activity_delivery_txtCity);
        txtDeliveryDate = (EditText) findViewById(R.id.activity_delivery_txtDeliveryDate);
        txtName = (EditText) findViewById(R.id.activity_delivery_txtName);
        txtPhone = (EditText) findViewById(R.id.activity_delivery_txtPhone);
        txtEmail = (EditText) findViewById(R.id.activity_delivery_txtEmail);
        txtRemark = (EditText) findViewById(R.id.activity_delivery_txtRemark);

        lblExtraDeliveryInfo = (TextView) findViewById(R.id.activity_delivery_lblExtraDetailInformation);

        rlDeliveryAddressDetails = (RelativeLayout) findViewById(R.id.activity_delivery_rlDeliveryAddressDetails);
    }

    private void validateInput() {
        util.editTextListener(txtPostcode);
        util.editTextListener(txtHouseNumber);
        util.editTextListener(txtDeliveryDate);
    }
}

我只想说代码可以在 BlueStacks 模拟器上运行。

Jelly Bean_MR1（4.2 和 4.2.1）上的 setError 存在一个已知错误。不过，我假设您正在测试的 Nexus 7 正在运行这些 Android 版本之一。看这里：http://code.google.com/p/android/issues/detail?id=40417

当您将焦点放在该 EditText 字段上时，将会显示该错误，但是当您失去焦点时，错误图标将不可见，无法通知用户该问题。