Kotlin和RecyclerView的一个demo

Kotlin和RecyclerView的一个demo

Kotlin最近比较火,我简单学了一下,写了个小demo,RecyclerView的.

1.使用到的东西

语言:Kotlin 不会配置的点这里….滑稽

RecyclerView

OkHttp3

RxJava

RxAndroid

Glide

Gson

2.需要引入的库

implementation 'com.android.support:recyclerview-v7:26.0.0'
implementation 'com.squareup.okhttp3:okhttp:3.8.1'
implementation 'io.reactivex.rxjava2:rxjava:2.1.2'
implementation 'io.reactivex.rxjava2:rxandroid:2.0.1'
implementation 'com.google.code.gson:gson:2.8.1'
implementation 'com.github.bumptech.glide:glide:4.0.0'

3.首先来看一下RecyclerView子项的布局吧

item_news.xml

就是一个ImageView和一个TextView

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="100dp"
android:background="#7dd9da"
android:gravity="center_vertical"
android:orientation="horizontal">

<ImageView
android:id="@+id/iv_news_des"
android:layout_width="80dp"
android:layout_height="80dp"
android:layout_marginStart="10dp"
android:scaleType="centerCrop"
android:src="@mipmap/ic_launcher"/>

<TextView
android:id="@+id/tv_news_title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="10dp"
android:ellipsize="end"
android:maxLines="1"
android:text="震惊...."
android:textColor="#AA000000"
android:textSize="20sp"
/>

</LinearLayout>

4.model,模型类

/**
* description：
* author feiyang
* create at 2017/8/3 17:37
*/
data class News(

@SerializedName("author_name")
var authorName: String?,
@SerializedName("category")
var category: String?,
@SerializedName("date")
var date: String?,
@SerializedName("thumbnail_pic_s")
var thumbnailPicS: String?,
@SerializedName("title")
var title: String?,
@SerializedName("uniquekey")
var uniquekey: String?,
@SerializedName("url")
var url: String?

)

5.adapter(*重要)

/**
* description：RecyclerView的adapter
* author feiyang
* create at 2017/8/3 17:41
*/
class NewsAdapter : RecyclerView.Adapter
<NewsAdapter.ViewHolder> {

private var context: Context? = null
private var newsList: ArrayList<News>? = null

//这是构造方法
constructor(context: Context, newsList: ArrayList<News>) {
this.context = context
this.newsList = newsList
}

class ViewHolder : RecyclerView.ViewHolder {

var ivDes: ImageView
var tvTitle: TextView

constructor(itemView: View) : super(itemView) {
ivDes = itemView.findViewById(R.id.iv_news_des)
tvTitle = itemView.findViewById(R.id.tv_news_title)
}
}

override fun onBindViewHolder(holder: ViewHolder?, position: Int) {
if (newsList?.size as Int > position) {
val news = newsList?.get(position)
//使用Glide加载图片
Glide.with(context).load(news?.thumbnailPicS).into(holder?.ivDes)
//设置标题
holder?.tvTitle?.text = news?.title
}
}

override fun getItemCount(): Int {
return newsList?.size as Int
}

override fun onCreateViewHolder(parent: ViewGroup?, viewType: Int): ViewHolder {
val view = LayoutInflater.from(parent?.context).inflate(R.layout.item_news, parent, false)
return ViewHolder(view)
}

/**
* 添加数据
*/
fun addData(dataList: ArrayList<News>): Unit {
//这里不用像java一样判断空了,这里肯定是非空的
if (dataList.size == 0) {
return
}
newsList?.addAll(dataList)
notifyDataSetChanged()
}

/**
* 更新数据
*/
fun updateData(dataList: ArrayList<News>): Unit {
if (dataList.size==0) {
return
}
newsList?.clear()
newsList?.addAll(dataList)
notifyDataSetChanged()
}

}

最后

核心代码就在上面了,如果想要完整代码的话,去这里下载 不要积分….