Android Studio 的ListView 的用法

<?xmlversion="1.0"encoding="utf-8"?><LinearLayoutxmlns:android="http://schemas.android.com/apk/res/android"android:id="@+id/activity_main"android:layout_width="match_parent"android:layout_height="match_parent"><ListViewandroid:layout_width="match_parent"android:layout_height="match_parent"android:id="@+id/lv"/></LinearLayout>

<?xmlversion="1.0"encoding="utf-8"?><LinearLayoutxmlns:android="http://schemas.android.com/apk/res/android"android:layout_width="match_parent"android:layout_height="match_parent"android:orientation="vertical"><TextViewandroid:id="@+id/tv"android:textSize="30sp"android:textColor="@color/black"android:layout_width="wrap_content"android:layout_height="wrap_content"/></LinearLayout>

packagecom.example.listviewtext;
publicclassBean {
Stringname;
publicStringgetName() {
returnname;
    }
publicvoidsetName(Stringname) {
this.name=name;
    }
}

packagecom.example.listviewtext;
importandroid.content.Context;
importandroid.view.LayoutInflater;
importandroid.view.View;
importandroid.view.ViewGroup;
importandroid.widget.BaseAdapter;
importandroid.widget.TextView;
importjava.util.List;
publicclassMyAdapterextendsBaseAdapter {
privateList<Bean>data;//创建私有的Bean类的dataprivateContextcontext;
publicMyAdapter(List<Bean>data, Contextcontext) {
this.data=data;
this.context=context;
    }
@OverridepublicintgetCount() {
returndata.size();//获取data的长度    }
@OverridepublicObjectgetItem(inti) {
returnnull;
    }
@OverridepubliclonggetItemId(inti) {//获取idreturni;
    }
@OverridepublicViewgetView(inti, Viewview, ViewGroupviewGroup) {
if (view==null){//防止view不停的新建，view=LayoutInflater.from(context).inflate(R.layout.list_item,viewGroup,false);
        }
TextViewtextView=view.findViewById(R.id.tv);
textView.setText(data.get(i).getName());//系统会去R文件里面找type类型的值匹配String值returnview;
    }
}

packagecom.example.listviewtext;
importandroidx.appcompat.app.AppCompatActivity;
importandroid.os.Bundle;
importandroid.view.View;
importandroid.widget.ListView;
importjava.util.ArrayList;
importjava.util.List;
publicclassMainActivityextendsAppCompatActivity {
privateList<Bean>data=newArrayList<>();//ArrayList 类是一个可以动态修改的数组，与普通数组的区别就是它是没有固定大小的限制，我们可以添加或删除元素@OverrideprotectedvoidonCreate(BundlesavedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
for (inti=1; i<=100; i++) {
Beanbean=newBean();
bean.setName("第"+i+"个");
data.add(bean);//通过add把数据加入到data里面        }
ListViewlistView=findViewById(R.id.lv);//获取id，就是上面讲的屏幕里面的列表的idlistView.setAdapter(newMyAdapter(data,this));//Adapter作用将各种数据以合适的形式显示在View中给用户看    }
}

packagecom.example.listviewtext;
importandroidx.appcompat.app.AppCompatActivity;
importandroid.os.Bundle;
importandroid.view.View;
importandroid.widget.ListView;
importjava.util.ArrayList;
importjava.util.List;
publicclassMainActivityextendsAppCompatActivity {
privateList<Bean>data=newArrayList<>();
@OverrideprotectedvoidonCreate(BundlesavedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Beanbean=newBean();
bean.setName("a");
data.add(bean);
Beanbean1=newBean();
bean1.setName("b");
data.add(bean1);
ListViewlistView=findViewById(R.id.lv);
listView.setAdapter(newMyAdapter(data,this));
    }
}

<?xmlversion="1.0"encoding="utf-8"?><LinearLayoutxmlns:android="http://schemas.android.com/apk/res/android"android:layout_width="match_parent"android:layout_height="match_parent"><ListViewandroid:id="@+id/listView"android:layout_width="match_parent"android:layout_height="match_parent"/></LinearLayout>

packagecom.example.listview2importandroidx.appcompat.app.AppCompatActivityimportandroid.os.Bundleimportandroid.widget.ArrayAdapterimportkotlinx.android.synthetic.main.activity_main.*classMainActivity : AppCompatActivity() {
privatevaldata=listOf("1","2","3","4","5","6","7","8","9","10","11","12","13","14","15")
overridefunonCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
valadapter=ArrayAdapter(this,android.R.layout.simple_list_item_1,data)
listView.adapter=adapter    }
}