Question

我遇到TextInputEditText选择属性的正确数据绑定问题。

这是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">

    <data>
        <variable name="inputViewModel" type="com.example.ui.TextInputViewModel"/>
    </data>

    <FrameLayout

        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <android.support.design.widget.TextInputLayout
            android:id="@+id/layoutInput"
            android:hint="@{inputViewModel.hint}"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            app:errorEnabled="@{!inputViewModel.valid}"
            app:error="@{inputViewModel.errorMessage}">

            <android.support.design.widget.TextInputEditText
                android:id="@+id/editInput"
                android:text="@={inputViewModel.value}"
                android:inputType="@{inputViewModel.inputType}"
                android:maxLines="1"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                app:selection="@{inputViewModel.selection}"
                app:setOnFocusChangeListener="@{inputViewModel.onFocusChangeListener}"
                app:addTextChangedListener="@{inputViewModel.watcher}" />
        </android.support.design.widget.TextInputLayout>
    </FrameLayout>
</layout>

MVVM类：

@Getter
@Setter
public class InputModel {
    private String value;
    private String errorMessage;
    private boolean valid;
    private String hint;
    private int inputType;
    private int selection;
}

    public abstract class BaseInputViewModel extends BaseObservable{
    protected InputModel mInputModel;

    public BaseInputViewModel(InputModel inputModel){
        this.mInputModel = inputModel;
    }
   }


public class TextInputViewModel extends BaseInputViewModel {

    public TextInputViewModel() {
        setWatcher(new TextWatcher() {

            @Override
            public void beforeTextChanged(CharSequence s, int start, int count, int after) {
                Log.d("TextInputViewModel","getSelection1: " + getSelection());

            }

            @Override
            public void onTextChanged(CharSequence value, int start, int before, int count) {
                Log.d("TextInputViewModel","getSelection2: " + getSelection());

            }

            @Override
            public void afterTextChanged(Editable s) {
                Log.d("TextInputViewModel","getSelection3: " + getSelection());

            }
        });
    }

    @Bindable
    public int getSelection() {
        return mInputModel.getSelection();
    }

    @Bindable
    public TextWatcher getWatcher() {
        return watcher;
    }

    public void setWatcher(TextWatcher watcher) {
        this.watcher = watcher;
        notifyPropertyChanged(BR.watcher);
     }
    }
}



  public class TextInputVie extends FrameLayout {

        public TextInputVie(Context context) {
            super(context);
            initView(context, null);
        }

        public TextInputVie(Context context, AttributeSet attrs) {
            super(context, attrs);
            initView(context, attrs);
        }

        void initView(@NonNull Context context, @Nullable AttributeSet attrs) {
            mViewModel = createViewModel();

            ViewDataBinding binding = DataBindingUtil.inflate(LayoutInflater.from(context), R.layout.text_input_layout, this, true);
            binding.setVariable(BR.inputViewModel, mViewModel);
        }

    }

不幸的是，只要光标位于编辑字段中，读取getSelection()始终返回0。另一方面，如果我打破分离规则并使用像view.getSelectionStart()那样的东西，我得到了正确的结果。但这更像是一种MVC / MVP方法。有没有人知道如何使用数据绑定绑定选择属性以获取当前光标位置？

Answer 1

使用Kotlin和双向数据绑定

创建一个适配器来设置光标位置，如下所述：

@BindingAdapter("app:cursorPosition")
fun setCursorSelection(view:TextInputEditText, flag:Boolean) {
    if (flag && view.text?.toString()?.length > 0) view.setSelection(view.text.toString().length)
}

通过传递您希望适配器设置光标位置或不设置光标位置的指示器天气，如下所示在xml中使用它：

 <android.support.design.widget.TextInputLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginLeft="@dimen/space_large"
            android:layout_marginRight="@dimen/space_large"
            android:layout_marginTop="@dimen/space_large"
            android:hint="@string/enter_username"
            app:errorText="@{(loginData.userNameErrorEnable &amp;&amp; loginData.name != null &amp;&amp; loginData.name.length() > 0 ) ? loginData.userNameError : null}"
            style="@style/MaterialEditText"
            app:layout_constraintTop_toBottomOf="@+id/headerImage">
            <android.support.design.widget.TextInputEditText
                android:id="@+id/usernameET"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:text="@={loginData.name}"
                app:clearTextChangeListener="@{loginData.userNameWatcher}"
                app:cursorPosition="@{loginData.name != null}" />
        </android.support.design.widget.TextInputLayout>

数据绑定＆amp;在TextInputEditText中选择

1 个答案: