在数据绑定中找不到属性的setter

Question

我在我的应用程序中使用LiveData,DataBinding和Kotlin.

我为RecyclerView定义了一个绑定适配器,如下所示:

   class MainListBindings {

    private val TAG = "TasksListBindings"

    companion object {

        @JvmStatic
        @SuppressWarnings("unchecked")
        @BindingAdapter("main_items")
        fun setItems(recyclerView: RecyclerView, items: MutableLiveData<List<Homeitem>>? = null) {

            val adapter: RecyclerMainAdapter = recyclerView.adapter as RecyclerMainAdapter
            //prevent use of null list
            items?.let {

                adapter.swapData(items)
            }
        }

    }
}

和我的reyclerView in XML分配给这个bindingAdapter,如下所示:

  <android.support.v7.widget.RecyclerView
      android:id="@+id/main_recycler"
      app:main_items="@{viewmodel.items}"
      android:layout_width="match_parent"
      android:layout_height="match_parent"/>

在我的ViewModel中,我使用过

val items = MutableLiveData<List<Homeitem>>()

创建列表.

但我在构建应用程序时遇到此错误:

Found data binding errors.
****/ data binding error ****msg:Cannot find the setter for attribute 'app:main_items' with parameter type android.arch.lifecycle.MutableLiveData<java.util.List<project.data.pojo.Homeitem>> on android.support.v7.widget.RecyclerView. file:/home/user/Yara/bazinama_mag/bazinama/app/src/main/res/layout/fragment_main.xml loc:22:24 - 22:38 ****\ data binding error ****

Answer 1

这个错误可能有不同的原因,但在我的情况下,问题出现了,因为我没有添加apply plugin: 'kotlin-kapt'和apply plugin: 'kotlin-android-extensions'我的Gradle.

添加这些插件你有后更换您的annotationProcessors用kapt.

在那之后,每件事情都可能顺利进行.

Answer 2

绑定适配器

    @JvmStatic
    @BindingAdapter("main_items")
    fun setItems(recyclerView: RecyclerView, items: MutableLiveData<List<String>>) {

    }

模型

 class User : ViewModel(){
        lateinit var list: MutableLiveData<List<String>>
    }

绑定数据

 val items = ViewModelProviders.of(this@FragmentName)
                .get(RecyclerViewHelper.User::class.java)
    mBinding!!.user = items

布局

<layout>
     <data>
        <variable
            name="user"
            type="com.XXX.view.recylerview.RecyclerViewHelper.User" />
    </data>

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">

        <android.support.v7.widget.RecyclerView
            android:id="@+id/helper_list"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            app:layoutManager="android.support.v7.widget.LinearLayoutManager"
            app:main_items="@{user.list}" />

    </RelativeLayout>

</layout>