使用 Android 数据绑定在 EditText text.length() > 0 时启用按钮
Enable Button when EditText text.length() > 0 using Android Data Binding
我正在尝试在有人开始在 EditText 中书写时启用该按钮。
我将按钮的启用 属性 设置为 android:enabled="@{editText.text.length() > 0}"。 =16=]
效果很好。但是当我尝试使用两种数据绑定将 EditText 绑定到 ViewModel 时它停止工作了。
正是这条线造成了差异。
android:text="@={signUpViewModel.Phone}"
没有这个,它工作正常!可能是什么原因?
下面是完整的XML.
<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools">
<data>
<variable
name="signUpViewModel"
type="com.qenetech.africapuzzle.signup.SignUpViewModel" />
<variable
name="editText_verify_phone_number"
type="android.widget.EditText" />
</data>
<android.support.constraint.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
tools:context=".signup.verify_phone.EnterPhoneFragment">
<Spinner
android:id="@+id/spinner_country"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginStart="16dp"
android:layout_marginTop="60dp"
android:layout_marginEnd="16dp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<LinearLayout
android:id="@+id/linearLayout"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginTop="60dp"
android:gravity="center"
android:orientation="horizontal"
android:weightSum="10"
app:layout_constraintEnd_toEndOf="@+id/spinner_country"
app:layout_constraintHorizontal_bias="0.0"
app:layout_constraintStart_toStartOf="@+id/spinner_country"
app:layout_constraintTop_toBottomOf="@+id/spinner_country">
<android.support.design.widget.TextInputLayout
android:layout_width="0dp"
android:layout_weight="2"
android:layout_height="wrap_content"
android:textColorHint="@android:color/darker_gray">
<android.support.design.widget.TextInputEditText
android:id="@+id/editText_verify_phone_country_code"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:ems="10"
android:text="@={signUpViewModel.CountryCode}"
android:inputType="phone" />
</android.support.design.widget.TextInputLayout>
<android.support.design.widget.TextInputLayout
android:id="@+id/etPhoneLayout"
android:layout_width="0dp"
android:layout_weight="8"
android:layout_height="wrap_content"
android:textColorHint="@android:color/darker_gray">
<android.support.design.widget.TextInputEditText
android:id="@+id/editText_verify_phone_number"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="@={signUpViewModel.Phone}"
android:hint="@string/enter_phone_number"
android:inputType="phone"/>
</android.support.design.widget.TextInputLayout>
</LinearLayout>
<Button
style="@style/Button.Primary"
android:id="@+id/button_verify_phone"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginTop="40dp"
android:text="@string/next"
android:textSize="@dimen/text_medium"
android:enabled="@{editTextVerifyPhoneNumber.text.length() > 0}"
app:layout_constraintEnd_toEndOf="@+id/linearLayout"
app:layout_constraintHorizontal_bias="0.498"
app:layout_constraintStart_toStartOf="@+id/linearLayout"
app:layout_constraintTop_toBottomOf="@+id/linearLayout" />
</android.support.constraint.ConstraintLayout>
</layout>
下面是ViewModel
public class SignUpViewModel extends ViewModel {
public MutableLiveData<String> Phone = new MutableLiveData<>();
public MutableLiveData<String> CountryCode = new MutableLiveData<>();
}
以及我与 ViewModel 一起使用的 Fragment
public class EnterPhoneFragment extends Fragment {
private SignUpViewModel signUpViewModel;
private SignupEnterPhoneFragmentBinding binding;
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container,
@Nullable Bundle savedInstanceState) {
binding = DataBindingUtil.inflate(inflater, R.layout.signup_enter_phone_fragment, container, false);
View root = binding.getRoot();
signUpViewModel = ViewModelProviders.of(this).get(SignUpViewModel.class);
binding.setSignUpViewModel(signUpViewModel);
Spinner spinner = root.findViewById(R.id.spinner_country);
spinner.setAdapter(new CountrySpinnerAdapter(getContext()));
return root;
}
@Override
public void onActivityCreated(@Nullable Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
}
}
使用TextUtils
判断是否启用按钮。
将其添加到布局中
<data>
<variable
name="signUpViewModel"
type="com.qenetech.africapuzzle.signup.SignUpViewModel" />
<import type="android.text.TextUtils" />
</data>
然后
<Button
style="@style/Button.Primary"
android:id="@+id/button_verify_phone"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginTop="40dp"
android:text="@string/next"
android:textSize="@dimen/text_medium"
android:enabled="@{!TextUtils.isEmpty(signUpViewModel.phone)}"
app:layout_constraintEnd_toEndOf="@+id/linearLayout"
app:layout_constraintHorizontal_bias="0.498"
app:layout_constraintStart_toStartOf="@+id/linearLayout"
app:layout_constraintTop_toBottomOf="@+id/linearLayout" />
另外别忘了打电话
binding.setLifecycleOwner(this)
在 onViewCreated
.
我正在尝试在有人开始在 EditText 中书写时启用该按钮。
我将按钮的启用 属性 设置为 android:enabled="@{editText.text.length() > 0}"。 =16=]
效果很好。但是当我尝试使用两种数据绑定将 EditText 绑定到 ViewModel 时它停止工作了。
正是这条线造成了差异。
android:text="@={signUpViewModel.Phone}"
没有这个,它工作正常!可能是什么原因?
下面是完整的XML.
<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools">
<data>
<variable
name="signUpViewModel"
type="com.qenetech.africapuzzle.signup.SignUpViewModel" />
<variable
name="editText_verify_phone_number"
type="android.widget.EditText" />
</data>
<android.support.constraint.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
tools:context=".signup.verify_phone.EnterPhoneFragment">
<Spinner
android:id="@+id/spinner_country"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginStart="16dp"
android:layout_marginTop="60dp"
android:layout_marginEnd="16dp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<LinearLayout
android:id="@+id/linearLayout"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginTop="60dp"
android:gravity="center"
android:orientation="horizontal"
android:weightSum="10"
app:layout_constraintEnd_toEndOf="@+id/spinner_country"
app:layout_constraintHorizontal_bias="0.0"
app:layout_constraintStart_toStartOf="@+id/spinner_country"
app:layout_constraintTop_toBottomOf="@+id/spinner_country">
<android.support.design.widget.TextInputLayout
android:layout_width="0dp"
android:layout_weight="2"
android:layout_height="wrap_content"
android:textColorHint="@android:color/darker_gray">
<android.support.design.widget.TextInputEditText
android:id="@+id/editText_verify_phone_country_code"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:ems="10"
android:text="@={signUpViewModel.CountryCode}"
android:inputType="phone" />
</android.support.design.widget.TextInputLayout>
<android.support.design.widget.TextInputLayout
android:id="@+id/etPhoneLayout"
android:layout_width="0dp"
android:layout_weight="8"
android:layout_height="wrap_content"
android:textColorHint="@android:color/darker_gray">
<android.support.design.widget.TextInputEditText
android:id="@+id/editText_verify_phone_number"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="@={signUpViewModel.Phone}"
android:hint="@string/enter_phone_number"
android:inputType="phone"/>
</android.support.design.widget.TextInputLayout>
</LinearLayout>
<Button
style="@style/Button.Primary"
android:id="@+id/button_verify_phone"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginTop="40dp"
android:text="@string/next"
android:textSize="@dimen/text_medium"
android:enabled="@{editTextVerifyPhoneNumber.text.length() > 0}"
app:layout_constraintEnd_toEndOf="@+id/linearLayout"
app:layout_constraintHorizontal_bias="0.498"
app:layout_constraintStart_toStartOf="@+id/linearLayout"
app:layout_constraintTop_toBottomOf="@+id/linearLayout" />
</android.support.constraint.ConstraintLayout>
</layout>
下面是ViewModel
public class SignUpViewModel extends ViewModel {
public MutableLiveData<String> Phone = new MutableLiveData<>();
public MutableLiveData<String> CountryCode = new MutableLiveData<>();
}
以及我与 ViewModel 一起使用的 Fragment
public class EnterPhoneFragment extends Fragment {
private SignUpViewModel signUpViewModel;
private SignupEnterPhoneFragmentBinding binding;
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container,
@Nullable Bundle savedInstanceState) {
binding = DataBindingUtil.inflate(inflater, R.layout.signup_enter_phone_fragment, container, false);
View root = binding.getRoot();
signUpViewModel = ViewModelProviders.of(this).get(SignUpViewModel.class);
binding.setSignUpViewModel(signUpViewModel);
Spinner spinner = root.findViewById(R.id.spinner_country);
spinner.setAdapter(new CountrySpinnerAdapter(getContext()));
return root;
}
@Override
public void onActivityCreated(@Nullable Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
}
}
使用TextUtils
判断是否启用按钮。
将其添加到布局中
<data>
<variable
name="signUpViewModel"
type="com.qenetech.africapuzzle.signup.SignUpViewModel" />
<import type="android.text.TextUtils" />
</data>
然后
<Button
style="@style/Button.Primary"
android:id="@+id/button_verify_phone"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginTop="40dp"
android:text="@string/next"
android:textSize="@dimen/text_medium"
android:enabled="@{!TextUtils.isEmpty(signUpViewModel.phone)}"
app:layout_constraintEnd_toEndOf="@+id/linearLayout"
app:layout_constraintHorizontal_bias="0.498"
app:layout_constraintStart_toStartOf="@+id/linearLayout"
app:layout_constraintTop_toBottomOf="@+id/linearLayout" />
另外别忘了打电话
binding.setLifecycleOwner(this)
在 onViewCreated
.