Android(安卓)Studio Kotlin开发之ListView
16lz
2021-12-04
Android Studio Kotlin开发之ListView
- Android Studio Kotlin开发之ListView
-
- ListView的简单用法
-
- 效果图
- 知识讲解
-
- ArrayAdapter
- 源代码
-
- MainActivity.kt
- activity_main.xml
- 定制ListView界面
-
- 效果图
- 源代码
-
- MainActivity.kt
- fruitAdapter.kt
- Fruit.kt
- activity_main.xml
- fruit_item.xml
- Referecces
Android Studio Kotlin开发之ListView
ListView的简单用法
效果图
知识讲解
ArrayAdapter
在下文源代码中有这样一句
val adapter = ArrayAdapter<String>(this,android.R.layout.simple_list_item_1,data)这段代码是创建一个数组适配器的代码，里面有三个参数，第一个参数是上下文，就是当前的Activity, 第二个参数是android sdk中自己内置的一个布局，它里面只有一个TextView，这个参数是表明我们数组中每一条数据的布局是这个view，就是将每一条数据都显示在这个view上面；第三个参数就是我们要显示的数据。listView会根据这三个参数，遍历adapterData里面的每一条数据，读出一条，显示到第二个参数对应的布局中，这样就形成了我们看到的listView. 1
源代码
MainActivity.kt
package com.example.listviewtestimport androidx.appcompat.app.AppCompatActivityimport android.os.Bundleimport android.widget.ArrayAdapterimport android.widget.ListAdapterimport kotlinx.android.synthetic.main.activity_main.*class MainActivity : AppCompatActivity() { private val data = listOf("apple","pear","apricot","peach","grape","banana","pineapple","plum","watermelon","orange","lemon","mango","strawberry", "medlar","mulberry","nectarine","cherry","pomegranate","fig","persimmon") override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_main) val adapter = ArrayAdapter<String>(this,android.R.layout.simple_list_item_1,data) listView.adapter = adapter }}activity_main.xml
<?xml version="1.0" encoding="utf-8"?><LinearLayout 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=".MainActivity"> <ListView android:id="@+id/listView" android:layout_width="match_parent" android:layout_height="match_parent" />LinearLayout>定制ListView界面
效果图
源代码
MainActivity.kt
package com.example.listviewtestimport androidx.appcompat.app.AppCompatActivityimport android.os.Bundleimport android.widget.ArrayAdapterimport android.widget.ListAdapterimport kotlinx.android.synthetic.main.activity_main.*import java.util.ArrayListclass MainActivity : AppCompatActivity() { // private val data = listOf("apple","pear","apricot","peach","grape","banana","pineapple","plum","watermelon","orange","lemon","mango","strawberry",// "medlar","mulberry","nectarine","cherry","pomegranate","fig","persimmon") private val fruitList = ArrayList<Fruit>() override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_main) initFruits() val adapter = FruitAdapter(this,R.layout.fruit_item,fruitList) listView.adapter = adapter } private fun initFruits() { repeat(2){ fruitList.add(Fruit("apple",R.drawable.pricture)) fruitList.add(Fruit("banana",R.drawable.pricture)) fruitList.add(Fruit("orange",R.drawable.pricture)) fruitList.add(Fruit("watermelon",R.drawable.pricture)) fruitList.add(Fruit("pear",R.drawable.pricture)) fruitList.add(Fruit("grape",R.drawable.pricture)) fruitList.add(Fruit("pineapple",R.drawable.pricture)) fruitList.add(Fruit("strawberry",R.drawable.pricture)) fruitList.add(Fruit("cherry",R.drawable.pricture)) fruitList.add(Fruit("mango",R.drawable.pricture)) } }}fruitAdapter.kt
package com.example.listviewtestimport android.app.Activityimport android.view.LayoutInflaterimport android.view.Viewimport android.view.ViewGroupimport android.widget.ArrayAdapterimport android.widget.ImageViewimport android.widget.TextViewclass FruitAdapter(activity: Activity, val resourceId: Int, data: List<Fruit>) : ArrayAdapter<Fruit>(activity, resourceId, data) { override fun getView(position: Int, convertView: View?, parent: ViewGroup): View { val view = LayoutInflater.from(context).inflate(resourceId, parent, false) val fruitImage: ImageView = view.findViewById(R.id.fruitImage) val fruitName: TextView = view.findViewById(R.id.fruitName) val fruit = getItem(position) if (fruit!=null){ fruitImage.setImageResource(fruit.imageId) fruitName.text = fruit.name } return view }}Fruit.kt
package com.example.listviewtestclass Fruit(val name:String,val imageId:Int)activity_main.xml
<?xml version="1.0" encoding="utf-8"?><LinearLayout 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=".MainActivity"> <ListView android:id="@+id/listView" android:layout_width="match_parent" android:layout_height="match_parent" />LinearLayout>fruit_item.xml
<?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="60dp"> <ImageView android:id="@+id/fruitImage" android:layout_width="40dp" android:layout_height="40dp" android:layout_gravity="center_vertical" android:layout_marginLeft="10dp"/> <TextView android:id="@+id/fruitName" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="center_vertical" android:layout_marginLeft="10dp" />LinearLayout>Referecces
ArrayAdapter参数的理解 ↩︎
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