autojs之RecycleView抽丝剥茧

作者: 牙叔

使用情景: 解析RecycleView常用方法

---

前置知识

1. RecyclerView 复用 Item 的工作 Google 已经封装
2. 自定义Adapter必须重写三个方法:
   • onCreateViewHolder
   • onBindViewHolder
   • getItemCount

---

了解每个方法的作用

1. onCreateViewHolder 视图创建
2. onBindViewHolder 数据绑定
3. getItemCount 数据总数

---

类比

1. 视图创建: 视图比作礼盒, 礼盒里面有一些格子, 规划成为一个一个固定的格子, 格子类型可以一样, 也可以不一样
2. 数据绑定: 把棒棒糖, 瓜子, 花生这些零食放到格子里

---

adapter

adapter中包含holder, holder处理view

---

代码分小段

1.主布局, 就一个RecyclerView

ui.layout(
  <vertical>
    <androidx.recyclerview.widget.RecyclerView id="recyclerView" h="*" w="*" />
  </vertical>
);

2. 两种礼盒布局

let redGiftBoxXml = (
  <card cardCornerRadius="10" cardElevation="10dp" margin="10">
    <horizontal bg="#88ff0000" padding="10" layout_width="wrap_content" layout_height="wrap_content">
      <img src="@drawable/ic_brightness_4_black_48dp"></img>
      <text>棒棒糖</text>
      <text id="lollipops"></text>
      <text>花生</text>
      <text id="melonSeeds"></text>
      <text>瓜子</text>
      <text id="peanut"></text>
    </horizontal>
  </card>
);
let blueGiftBoxXml = (
  <horizontal layout_width="match_parent" layout_height="wrap_content">
    <View layout_weight="1"></View>
    <card cardCornerRadius="10" cardElevation="6dp" margin="10">
      <horizontal bg="#550000ff" gravity="right" padding="10">
        <text>棒棒糖</text>
        <text id="lollipops">11111111111</text>
        <text>花生</text>
        <text id="melonSeeds"></text>
        <text>瓜子</text>
        <text id="peanut"></text>
        <img src="@drawable/ic_brightness_5_black_48dp"></img>
      </horizontal>
    </card>
  </horizontal>
);

3. adapter

function createGiftBoxAdapter(giftBoxList) {
    
    
  return RecyclerView.Adapter({
    
    
    onCreateViewHolder: function (parent, viewType) {
    
    
      // 视图创建
      let view;
      let holder;
      if (viewType === 0) {
    
    
        view = ui.inflate(redGiftBoxXml, parent, false);
        holder = JavaAdapter(RecyclerView.ViewHolder, {
    
    }, view);
      } else {
    
    
        view = ui.inflate(blueGiftBoxXml, parent, false);
        // Holder
        holder = JavaAdapter(RecyclerView.ViewHolder, {
    
    }, view);
      }
      return holder;
    },
    onBindViewHolder: function (holder, position) {
    
    
      // 数据绑定
      giftBox = giftBoxList[position];
      holder.itemView.lollipops.setText(giftBox.getLollipops());
      holder.itemView.melonSeeds.setText(giftBox.getMelonSeeds());
      holder.itemView.peanut.setText(giftBox.getPeanut());
    },
    getItemCount: function () {
    
    
      return giftBoxList.length;
    },
    getItemViewType: function (position) {
    
    
      return giftBoxList[position].getGiftType();
    },
  });
}

4. view有了, adapter也有了(holder在adapter中), 我们就可以加载数据了

5. 创建数据

let giftBoxList = [];
for (var i = 0; i < 10; i++) {
    
    
  giftBoxList.push(new GiftBox(i + "个", i * 2 + "斤", i * 3 + "袋"));
}

6. 加载数据

recycleAdapter = createGiftBoxAdapter(giftBoxList);
recyclerView.setAdapter(recycleAdapter);

7. 效果展示

完整代码

"ui";
importClass(Packages.androidx.recyclerview.widget.RecyclerView);
importClass(Packages.androidx.recyclerview.widget.LinearLayoutManager);

ui.layout(
  <vertical>
    <androidx.recyclerview.widget.RecyclerView id="recyclerView" h="*" w="*" />
  </vertical>
);

// lollipops: // 棒棒糖
// melonSeeds: //瓜子
// peanut: //花生

// 过年买东西, 瓜子,花生,棒棒糖

function GiftBox(lollipops, melonSeeds, peanut) {
    
    
  this.lollipops = lollipops;
  this.melonSeeds = melonSeeds;
  this.peanut = peanut;
}
GiftBox.prototype.getLollipops = function () {
    
    
  return this.lollipops;
};
GiftBox.prototype.getMelonSeeds = function () {
    
    
  return this.melonSeeds;
};
GiftBox.prototype.getPeanut = function () {
    
    
  return this.peanut;
};
GiftBox.prototype.getGiftType = function () {
    
    
  return random(0, 1);
};

// 礼盒界面
let redGiftBoxXml = (
  <card cardCornerRadius="10" cardElevation="10dp" margin="10">
    <horizontal bg="#88ff0000" padding="10" layout_width="wrap_content" layout_height="wrap_content">
      <img src="@drawable/ic_brightness_4_black_48dp"></img>
      <text>棒棒糖</text>
      <text id="lollipops"></text>
      <text>花生</text>
      <text id="melonSeeds"></text>
      <text>瓜子</text>
      <text id="peanut"></text>
    </horizontal>
  </card>
);
let blueGiftBoxXml = (
  <horizontal layout_width="match_parent" layout_height="wrap_content">
    <View layout_weight="1"></View>
    <card cardCornerRadius="10" cardElevation="6dp" margin="10">
      <horizontal bg="#550000ff" gravity="right" padding="10">
        <text>棒棒糖</text>
        <text id="lollipops">11111111111</text>
        <text>花生</text>
        <text id="melonSeeds"></text>
        <text>瓜子</text>
        <text id="peanut"></text>
        <img src="@drawable/ic_brightness_5_black_48dp"></img>
      </horizontal>
    </card>
  </horizontal>
);

function createGiftBoxAdapter(giftBoxList) {
    
    
  return RecyclerView.Adapter({
    
    
    onCreateViewHolder: function (parent, viewType) {
    
    
      // 视图创建
      let view;
      let holder;
      if (viewType === 0) {
    
    
        view = ui.inflate(redGiftBoxXml, parent, false);
        holder = JavaAdapter(RecyclerView.ViewHolder, {
    
    }, view);
      } else {
    
    
        view = ui.inflate(blueGiftBoxXml, parent, false);
        // Holder
        holder = JavaAdapter(RecyclerView.ViewHolder, {
    
    }, view);
      }
      return holder;
    },
    onBindViewHolder: function (holder, position) {
    
    
      // 数据绑定
      giftBox = giftBoxList[position];
      holder.itemView.lollipops.setText(giftBox.getLollipops());
      holder.itemView.melonSeeds.setText(giftBox.getMelonSeeds());
      holder.itemView.peanut.setText(giftBox.getPeanut());
    },
    getItemCount: function () {
    
    
      return giftBoxList.length;
    },
    getItemViewType: function (position) {
    
    
      return giftBoxList[position].getGiftType();
    },
  });
}

let recyclerView = ui.recyclerView;
// //设置布局管理器
layoutManager = new LinearLayoutManager(context);
recyclerView.setLayoutManager(layoutManager);
let giftBoxList = [];
for (var i = 0; i < 10; i++) {
    
    
  giftBoxList.push(new GiftBox(i + "个", i * 2 + "斤", i * 3 + "袋"));
}
//设置Adapter
recycleAdapter = createGiftBoxAdapter(giftBoxList);
recyclerView.setAdapter(recycleAdapter);

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