Android中使用Spinner实现下拉列表功能

spinner

　　spinner是一个列表选择框，会在用户选择后，展示一个列表供用户进行选择。spinner是viewgroup的间接子类，它和其他的android控件一样，数据需要使用adapter进行封装。

1，demo展示图片

2，布局代码

//(layout)activity_main
<linearlayout
 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"
 android:orientation="vertical"
 tools:context="com.test.spinner.mainactivity">
 <linearlayout
  android:layout_width="match_parent"
  android:layout_height="wrap_content"
  android:orientation="horizontal">
  <textview
   android:textsize="20sp"
   android:layout_margin="10dp"
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   android:text="今年的常规赛mvp："/>
  <textview
   android:id="@+id/text"
   android:textsize="20sp"
   android:layout_margintop="10dp"
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"/>
 </linearlayout>
 <spinner
  android:visibility="gone"
  android:id="@+id/spinner"
  android:layout_marginleft="10dp"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content">
 </spinner>
</linearlayout>
-------------------------------------------------------------------
//(layout)item
<linearlayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="horizontal"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:gravity="center_vertical">
 <imageview
  android:id="@+id/imageview"
  android:layout_width="80dp"
  android:layout_height="80dp"/>
 <textview
  android:id="@+id/textview"
  android:layout_marginleft="20dp"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"/>
</linearlayout>

3，activity代码

//mainactivity
import android.content.context;
import android.os.bundle;
import android.support.v7.app.appcompatactivity;
import android.view.menu;
import android.view.menuitem;
import android.view.view;
import android.widget.adapterview;
import android.widget.arrayadapter;
import android.widget.simpleadapter;
import android.widget.spinner;
import android.widget.textview;
import java.util.arraylist;
import java.util.hashmap;
import java.util.list;
import java.util.map;
import static com.test.spinner.r.id.simpleadapter;
public class mainactivity extends appcompatactivity {
 private context mcontext = mainactivity.this;
 private spinner mspinner;
 private arrayadapter<string> marrayadapter;
 private textview mtextview;
 private simpleadapter msimpleadapter;
 @override
 protected void oncreate(bundle savedinstancestate) {
  super.oncreate(savedinstancestate);
  setcontentview(r.layout.activity_main);
  initview();
  initdata();
 }
 private void initview(){
  mspinner = (spinner) findviewbyid(r.id.spinner);
  mtextview = (textview) findviewbyid(r.id.text);
 }
 private void initdata(){
  // 设置数据集
  list<string> list = new arraylist<>();
  list.add("哈登");
  list.add("莱昂纳德");
  list.add("詹姆斯");
  list.add("威斯布鲁克");
  list<map<string ,object>> maps = new arraylist<>();
  int[] icon = {r.mipmap.pic1 , r.mipmap.pic2, r.mipmap.pic3, r.mipmap.pic4};
  string[] iconname = {"哈登" , "莱昂纳德" , "詹姆斯" , "威斯布鲁克"};
  // 设置适配器
  marrayadapter = new arrayadapter<>(mcontext ,
    android.r.layout.simple_spinner_item , list);
  marrayadapter.setdropdownviewresource(android.r.layout.simple_spinner_dropdown_item);
  msimpleadapter = new simpleadapter(mcontext,
    maps , r.layout.item , new string[]{"image" , "text"} , new int[]{r.id.imageview ,r.id.textview});
  for(int i = 0 ; i < icon.length ; i++){
   map<string ,object> map = new hashmap<>();
   map.put("image", icon[i]);
   map.put("text" , iconname[i]);
   maps.add(map);
  }
 }
 @override
 public boolean oncreateoptionsmenu(menu menu) {
  getmenuinflater().inflate(r.menu.main , menu);
  return true;
 }
 @override
 public boolean onoptionsitemselected(menuitem item) {
  switch (item.getitemid()){
   case r.id.arrayadapter:
    mspinner.setvisibility(view.visible);
    mspinner.setadapter(marrayadapter);
    // 设置监听器
    mspinner.setonitemselectedlistener(new adapterview.onitemselectedlistener() {
     @override
     public void onitemselected(adapterview<?> adapterview, view view, int position, long id) {
      mtextview.settext(marrayadapter.getitem(position));
     }
     @override
     public void onnothingselected(adapterview<?> adapterview) {
     }
    });
    break;
   case simpleadapter:
    mspinner.setvisibility(view.visible);
    mspinner.setadapter(msimpleadapter);
    // 设置监听器
    mspinner.setonitemselectedlistener(new adapterview.onitemselectedlistener() {
     @override
     public void onitemselected(adapterview<?> adapterview, view view, int position, long id) {
      mtextview.settext(msimpleadapter.getitem(position)+"");
     }
     @override
     public void onnothingselected(adapterview<?> adapterview) {
     }
    });
    break;
   default:
    break;
  }
  return super.onoptionsitemselected(item);
 }
}

以上所述是小编给大家介绍的android中使用spinner实现下拉列表功能，希望对大家有所帮助