Java 将布尔值绑定到MVVM复选框

我试图通过viewmodel将布尔值绑定到视图，但是Android Studio抛出了一个错误，我找不到问题。viewModel.inflType是一个布尔值，android:checked也应该是一个布尔值

错误：“@{viewModel.infiltype}”与属性android:checked（attr）boolean不兼容。 消息{kind=ERROR，text=ERROR:“@{viewModel.infiltype}”与属性android:checked（attr）boolean不兼容，sources=[E:\SportveldOnderhoud\app\src\main\res\layou\list\u item\u check.xml:14]，原始消息=，工具名=可选的.of（AAPT）}”

我有以下代码（我将粘贴相关的代码片段）

Check.java（模型）

视图模型：

public class CheckViewModel extends BaseObservable {
    private Check mCheck;
    private Activity mActivity;

    public CheckViewModel(Activity activity) {
        mActivity = activity;
    }

    @Bindable
    public String getTitle() {
        return mCheck.getTitle();
    }

    @Bindable
    public String getRenderedDate() {
        return mCheck.getDate().toString();
    }

    @Bindable
    public boolean infillType() {
        return mCheck.isInfilltype();
    }

    public Check getCheck() {
        return mCheck;
    }

    public void setCheck(Check crime) {
        mCheck = crime;
        List<String> strings;
        notifyChange();
    }

    public void onCheckClicked() {
        Intent intent = CheckPagerActivity.newIntent(mActivity, mCheck.getId());
        mActivity.startActivity(intent);
    }
}

公共类CheckViewModel扩展了BaseObservable{
私人支票；
私人活动能力；
公共检查视图模型（活动）{
活动性=活动性；
}
@装订的
公共字符串getTitle（）{
返回mCheck.getTitle（）；
}
@装订的
公共字符串getRenderDate（）{
返回mCheck.getDate（）.toString（）；
}
@装订的
公共布尔内嵌类型（）{
返回mCheck.isInfilltype（）；
}
公共检查getCheck（）{
返回mCheck；
}
公共无效设置检查（检查犯罪）{
mCheck=犯罪；
列出字符串；
notifyChange（）；
}
勾选（）后的公共无效{
Intent-Intent=CheckPagerActivity.newIntent（mActivity，mCheck.getId（））；
主动性。主动性（意图）；
}
}

视图：

<?xml version="1.0" encoding="utf-8"?>
<layout>
    <data>
        <variable name="viewModel" type="nl.lekolkman.android.sportveldonderhoud.CheckViewModel" />
    </data>

    <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:tools="http://schemas.android.com/tools"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:onClick="@{() -> viewModel.onCheckClicked()}"
        >

        <CheckBox
            android:id="@+id/solved_check_box"
            android:checked="@{viewModel.infillType}"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentRight="true"/>

        <TextView
            android:id="@+id/title_text_view"
            android:text="@{viewModel.title}"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_toLeftOf="@id/solved_check_box"
            android:textStyle="bold"
            tools:text="Crime Title"/>

        <TextView
            android:id="@+id/date_text_view"
            android:text="@{`Date solved: ` + viewModel.renderedDate ?? `(not solved)`}"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_toLeftOf="@id/solved_check_box"
            android:layout_below="@id/title_text_view"
            tools:text="Check Date"/>

    </RelativeLayout>
</layout>

---

我对java不是非常熟悉，但我很确定在C#中，您的布尔值需要一个初始值（非null）才能正确绑定

试着改变

private boolean mInfilltype;

到

---

结果我不得不补充：

android { 
...
    dataBinding {
            enabled = true
        } 

内建gradle

---

然而，它仍然不起作用，但在build.gradle文件中将maven添加到存储库后，它确实起作用了

您可以使用或扩展Android复合视图绑定适配器

import androidx.databinding.BindingAdapter;
import androidx.databinding.BindingMethod;
import androidx.databinding.BindingMethods;
import androidx.databinding.InverseBindingListener;
import androidx.databinding.InverseBindingMethod;
import androidx.databinding.InverseBindingMethods;
import androidx.annotation.RestrictTo;
import android.widget.CompoundButton;
import android.widget.CompoundButton.OnCheckedChangeListener;
/**
 * @hide
 */
@RestrictTo(RestrictTo.Scope.LIBRARY)
@BindingMethods({
        @BindingMethod(type = CompoundButton.class, attribute = "android:buttonTint", method = "setButtonTintList"),
        @BindingMethod(type = CompoundButton.class, attribute = "android:onCheckedChanged", method = "setOnCheckedChangeListener"),
})
@InverseBindingMethods({
        @InverseBindingMethod(type = CompoundButton.class, attribute = "android:checked"),
})
public class CompoundButtonBindingAdapter {
    @BindingAdapter("android:checked")
    public static void setChecked(CompoundButton view, boolean checked) {
        if (view.isChecked() != checked) {
            view.setChecked(checked);
        }
    }
    @BindingAdapter(value = {"android:onCheckedChanged", "android:checkedAttrChanged"},
            requireAll = false)
    public static void setListeners(CompoundButton view, final OnCheckedChangeListener listener,
            final InverseBindingListener attrChange) {
        if (attrChange == null) {
            view.setOnCheckedChangeListener(listener);
        } else {
            view.setOnCheckedChangeListener(new OnCheckedChangeListener() {
                @Override
                public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                    if (listener != null) {
                        listener.onCheckedChanged(buttonView, isChecked);
                    }
                    attrChange.onChange();
                }
            });
        }
    }
}

---

Ref:

默认情况下，它们被初始化为false，如果您将类型声明为Boolean（object），您可以将其赋值为null，如果它是Boolean（小写b），则它是primitive，并且只能保存false/true。虽然此链接可以回答问题，但最好在此处包含答案的基本部分，并提供链接以供参考。如果链接页面发生更改，则仅链接的答案可能无效-

android { 
...
    dataBinding {
            enabled = true
        } 

import androidx.databinding.BindingAdapter;
import androidx.databinding.BindingMethod;
import androidx.databinding.BindingMethods;
import androidx.databinding.InverseBindingListener;
import androidx.databinding.InverseBindingMethod;
import androidx.databinding.InverseBindingMethods;
import androidx.annotation.RestrictTo;
import android.widget.CompoundButton;
import android.widget.CompoundButton.OnCheckedChangeListener;
/**
 * @hide
 */
@RestrictTo(RestrictTo.Scope.LIBRARY)
@BindingMethods({
        @BindingMethod(type = CompoundButton.class, attribute = "android:buttonTint", method = "setButtonTintList"),
        @BindingMethod(type = CompoundButton.class, attribute = "android:onCheckedChanged", method = "setOnCheckedChangeListener"),
})
@InverseBindingMethods({
        @InverseBindingMethod(type = CompoundButton.class, attribute = "android:checked"),
})
public class CompoundButtonBindingAdapter {
    @BindingAdapter("android:checked")
    public static void setChecked(CompoundButton view, boolean checked) {
        if (view.isChecked() != checked) {
            view.setChecked(checked);
        }
    }
    @BindingAdapter(value = {"android:onCheckedChanged", "android:checkedAttrChanged"},
            requireAll = false)
    public static void setListeners(CompoundButton view, final OnCheckedChangeListener listener,
            final InverseBindingListener attrChange) {
        if (attrChange == null) {
            view.setOnCheckedChangeListener(listener);
        } else {
            view.setOnCheckedChangeListener(new OnCheckedChangeListener() {
                @Override
                public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                    if (listener != null) {
                        listener.onCheckedChanged(buttonView, isChecked);
                    }
                    attrChange.onChange();
                }
            });
        }
    }
}