Android实验一 ListView的简单应用

1.需求：实现图书列表，点击一个图书，可查看详细图书信息

2.编写listview_main页面（主页面）

<?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="match_parent">
    <ListView
        android:id="@+id/listview"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</LinearLayout

3.编写listview_item列表页

<?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="match_parent">
    <ImageView
        android:id="@+id/bookImage"
        android:layout_width="40dp"
        android:layout_height="100dp"
        android:layout_gravity="center_vertical"
        android:layout_marginLeft="10dp"/>
    <TextView android:id="@+id/bookName"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_vertical"
        android:layout_marginLeft="10dp"
        android:textSize="20sp"/>
</LinearLayout>

4.编写item_detail页面（item详情页）

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".BookDetailActivity">

    <ImageView
        android:id="@+id/bookimage"
        android:layout_width="200dp"
        android:layout_height="200dp"
        android:layout_gravity="center_vertical"
        android:layout_marginStart="44dp"
        android:layout_marginLeft="44dp"
        android:layout_marginTop="44dp"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <TextView
        android:id="@+id/bookname"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"

        android:layout_marginTop="80dp"

        android:textSize="50sp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.272"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/bookimage" />

</androidx.constraintlayout.widget.ConstraintLayout>

5.建立Book.kt类

class Book(val name:String,val imageId:Int)

6.创建自定义图书适配器BookAdapter.kt

class BookAdapter(activity:Activity, val resourceId:Int, data:List<Book>):
    ArrayAdapter<Book>(activity,resourceId,data) {
    override fun getView(position: Int, convertView: View?, parent: ViewGroup): View {
//使用LayoutInflater加载子布局
        val view = LayoutInflater.from(context).inflate(resourceId,parent,false)
//调用view的findByID()方法获取ImageView和TextView实例
        val bookImage:ImageView=view.findViewById(R.id.bookImage)
        val bookName:TextView=view.findViewById(R.id.bookName)
//通过getItem()方法得到当前项的Book实例，并分别调用setImageResource()和setText()方法设置图片和文字
        val book=getItem(position)
        if(book!=null){
            bookImage.setImageResource(book.imageId)
            bookName.text=book.name
        }
        return view
    }

}

7.创建MainActivity

class ListViewMainActivity: AppCompatActivity()  {
    private val fruList=ArrayList<Book>()
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.listview_main)
        this.title="listview"
        initBook()
//建建适配器对象
        val adapter = BookAdapter(this,R.layout.listview_item,fruList)
        listview.adapter=adapter
//为适配器设置点击事件
        listview.setOnItemClickListener { _, _, position, _ ->
            val book=fruList[position]
//使用intent传递数据
            val intent = Intent(this,BookDetailActivity::class.java)
            intent.putExtra("book",book.name)
            intent.putExtra("image",book.imageId)
            Log.d("imageId","img数据时$book.imageId")
            startActivity(intent)
        }


    }
//初始化数据
    private fun initBook(){
        repeat(1){
            fruList.add(Book("Java编程思想",R.drawable.book1))
            fruList.add(Book("程序员修炼之道",R.drawable.book2))
            fruList.add(Book("零基础入门学习Python",R.drawable.book3))
            fruList.add(Book("Java从入门到精通",R.drawable.book4))
            fruList.add(Book("深入理解Java虚拟机",R.drawable.book5))
            fruList.add(Book("算法导论",R.drawable.book6))
            fruList.add(Book("Android开发艺术探索",R.drawable.book7))
            fruList.add(Book("Android进阶之光",R.drawable.book8))
            fruList.add(Book("疯狂Android",R.drawable.book9))
            fruList.add(Book("Android开发从入门到精通",R.drawable.book10))
        }
    }

}

6.创建BookDetailActivity.kt

class BookDetailActivity: AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.item_detail)
//接受数据并显示数据
        val bookdetail = intent.getStringExtra("book")
        val img = intent.getIntExtra("image",0)
        val imgview:ImageView=findViewById(R.id.bookimage)
        val bootv:TextView=findViewById(R.id.bookname)
        bootv.text=bookdetail
        Log.d("img","img数据时$img")
        Log.d("book","img数据时$bookdetail")
        imgview.setImageResource(img.toInt())

    }
}

7.配置AndroidManifest.xml

<activity android:name=".ListViewMainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity android:name=".BookDetailActivity">
            <intent-filter>
                <action android:name="bookDetail"/>
                <category android:name="android.intent.category.DEFAULT"/>
            </intent-filter>

8.效果图