Andriod Spinner下拉框使用详解

来源：互联网发布：异界大巫txt吾知编辑：程序博客网时间：2024/06/10 18:05

第一步:在activity_main.xml中引用spinner

<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:id="@+id/activity_main"    android:layout_width="match_parent"    android:layout_height="match_parent"    tools:context="myself.spinner.MainActivity">    <TextView        android:id="@+id/textView"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="Hello World!"        android:layout_marginTop="10dp"/>    <Spinner        android:id="@+id/spinner"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:layout_marginTop="24dp"        android:layout_below="@+id/textView"        android:layout_alignLeft="@+id/textView"        android:layout_alignStart="@+id/textView" /></RelativeLayout>

第二步:编写java代码

package myself.spinner;import android.os.Bundle;import android.support.v7.app.AppCompatActivity;import android.view.View;import android.widget.AdapterView;import android.widget.ArrayAdapter;import android.widget.Spinner;import android.widget.TextView;import java.util.ArrayList;import java.util.List;public class MainActivity extends AppCompatActivity implements AdapterView.OnItemSelectedListener{    private TextView textView;    private Spinner spinner;    private ArrayAdapter adapter;    private List<String>list;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        textView = (TextView) findViewById(R.id.textView);        spinner = (Spinner) findViewById(R.id.spinner);        //1.准备数据源        list = new ArrayList<>();        list.add("北京");        list.add("上海");        list.add("深圳");        list.add("广州");        //默认选择的是北京        textView.setText("您选择的城市是北京");        //2.实例化数组适配器        adapter = new ArrayAdapter(this, android.R.layout.simple_spinner_item, list);        //设置spinner下拉框的样式        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);        //3.视图控件加载适配器        spinner.setAdapter(adapter);        spinner.setOnItemSelectedListener(this);    }    //spinner选择每一项的事件    @Override    public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {        //adapter.getItem(postion)得到的是一个Object对象        String name =(String) adapter.getItem(position);        //String name = list.get(postion);        textView.setText("您选择的城市是"+name);    }    @Override    public void onNothingSelected(AdapterView<?> parent) {    }}

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