RecyclerView用于列表的显示,大家都很熟悉了,这里主要介绍下RecyclerView在kotlin中结合Databinding的使用
1.创建项目后需要在gradle中引入:
implementation 'com.android.support:recyclerview-v7:28.0.0-alpha1'
否则当你使用RecyclerView时会发现没办法引入。
2.布局文件:
这里因为我们使用的是Databinding所以使用的是layout开头的布局:
<layout xmlns:android="http://schemas.android.com/apk/res/android"
>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<android.support.v7.widget.RecyclerView
android:id="@+id/rv_person"
android:layout_width="match_parent"
android:layout_height="wrap_content">
</android.support.v7.widget.RecyclerView>
</LinearLayout>
</layout>
2.RecyclerView的初始化:
private fun initView(){
val layoutManager = LinearLayoutManager(this)
mBinding!!.rvPerson.layoutManager = layoutManager
mAdapter = PersonAdapter()
mBinding!!.rvPerson.adapter = mAdapter
}
可以看到我们直接使用mBinding!!.rvPerson 来得到RecyclerView就相当于java的findviewbyid,
mBinding!!.rvPerson.layoutManager = layoutManager就相当于java的setLayoutManager
mBinding!!.rvPerson.adapter = mAdapter就相当于java的setAdapter
3.adapter:
(1)BaseAdapter:
abstract class BaseAdapter<T>(var data: List<T> = listOf()) : RecyclerView.Adapter<BaseViewHolder>() {
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): BaseViewHolder {
return BaseViewHolder(DataBindingUtil.inflate(LayoutInflater.from(parent?.context), viewType, parent, false))
}
override fun getItemCount(): Int {
return data.size
}
fun refreshData(newData: List<T>) {
this.data = newData
this.notifyDataSetChanged()
}
}
open class BaseViewHolder(var dataBinding: ViewDataBinding) : RecyclerView.ViewHolder(dataBinding.root) {
}
BaseAdapter:通过这句话来绑定itemview BaseViewHolder(DataBindingUtil.inflate(LayoutInflater.from(parent?.context), viewType, parent, false))
(2)adapter:
class PersonAdapter : BaseAdapter<PersonBean>(){
override fun onBindViewHolder(holder: BaseViewHolder, position: Int) {
var binding : ViewDataBinding = holder.dataBinding
binding.setVariable(BR.personBean,data.get(position))
}
override fun getItemViewType(position: Int): Int {
return R.layout.item_person
}
}
adpater中主要通过:
var binding : ViewDataBinding = holder.dataBinding
binding.setVariable(BR.personBean,data.get(position))
来设置itemview的数据显示。
(2)布局文件:
<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android"
>
<data>
<import type="com.example.linwb.childrenstudy.R"/>
<variable
name="personBean"
type="com.example.linwb.childrenstudy.bean.PersonBean"/>
</data>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical"
>
<TextView
android:id="@+id/tv_name"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@{personBean.nickname}"
/>
</LinearLayout>
</layout>
布局文件也是使用Databinding的。
项目代码地址: