你需要一个旋转器。下面是一个例子:

spinner_1 = (Spinner) findViewById(R.id.spinner1);
spinner_1.setOnItemSelectedListener(this);
List<String> list = new ArrayList<String>(); 
list.add("RANJITH");
list.add("ARUN");
list.add("JEESMON");
list.add("NISAM");
list.add("SREEJITH");
list.add("SANJAY");
list.add("AKSHY");
list.add("FIROZ");
list.add("RAHUL");
list.add("ARJUN");
list.add("SAVIYO");
list.add("VISHNU");

ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, list);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner_1.setAdapter(adapter);


spinner_2 = (Spinner) findViewById(R.id.spinner_two);
spinner_2.setOnItemSelectedListener(this);
List<String> city = new ArrayList<String>();
city.add("KASARGOD");
city.add("KANNUR");
city.add("THRISSUR");
city.add("KOZHIKODE");
city.add("TRIVANDRUM");
city.add("ERNAMKULLAM");
city.add("WAYANAD");
city.add("PALAKKAD");
city.add("ALAPUZHA");
city.add("IDUKKI");
city.add("KOTTAYAM");
city.add("PATHANAMTHITTA");
city.add("KOLLAM");
city.add("MALAPPURAM");
ArrayAdapter<String> adapter2 = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, city);
adapter2.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner_2.setAdapter(adapter2);

@Override
public void onItemSelected(AdapterView<?> parent, View view, int position,
        long id) {
    // TODO Auto-generated method stub
    Toast.makeText(this, "YOUR SELECTION IS : " + parent.getItemAtPosition(position).toString(), Toast.LENGTH_SHORT).show();


}

@Override
public void onNothingSelected(AdapterView<?> parent) {
    // TODO Auto-generated method stub

}

下面是它的代码。

activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >

<Spinner
    android:id="@+id/static_spinner"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:layout_marginBottom="20dp"
    android:layout_marginTop="20dp" />

<Spinner
    android:id="@+id/dynamic_spinner"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content" />

strings.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
<string name="app_name">Ahotbrew.com - Dropdown</string> 
<string-array name="brew_array">
    <item>Cappuccino</item>
    <item>Espresso</item>
    <item>Mocha</item>
    <item>Caffè Americano</item>
    <item>Cafe Zorro</item>
</string-array> 

MainActivity

Spinner staticSpinner = (Spinner) findViewById(R.id.static_spinner);

    // Create an ArrayAdapter using the string array and a default spinner
    ArrayAdapter<CharSequence> staticAdapter = ArrayAdapter
            .createFromResource(this, R.array.brew_array,
                    android.R.layout.simple_spinner_item);

    // Specify the layout to use when the list of choices appears
    staticAdapter
            .setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);

    // Apply the adapter to the spinner
    staticSpinner.setAdapter(staticAdapter);

    Spinner dynamicSpinner = (Spinner) findViewById(R.id.dynamic_spinner);

    String[] items = new String[] { "Chai Latte", "Green Tea", "Black Tea" };

    ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
            android.R.layout.simple_spinner_item, items);

    dynamicSpinner.setAdapter(adapter);

    dynamicSpinner.setOnItemSelectedListener(new OnItemSelectedListener() {
        @Override
        public void onItemSelected(AdapterView<?> parent, View view,
                int position, long id) {
            Log.v("item", (String) parent.getItemAtPosition(position));
        }

        @Override
        public void onNothingSelected(AdapterView<?> parent) {
            // TODO Auto-generated method stub
        }
    });

这个例子来自 http://www.ahotbrew.com/android-dropdown-spinner-example/

这个代码对我来说很好，希望它也能帮助到你。

。

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical"
    android:padding="1dip" >
    <TextView
        android:id="@+id/spinnerItem"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:padding="2dp"
        android:textSize="12sp" >
    </TextView>
</RelativeLayout>

details.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical"
        android:layout_marginBottom="20dp"
        android:background="#FF00FF">   
    <Spinner
            android:id="@+id/dropStatus"
            android:layout_width="250dp"
            android:layout_height="30dp"
            android:layout_marginBottom="7dp"
            android:drawSelectorOnTop="true"/> 
</LinearLayout>

适配器类:

import java.util.ArrayList;

import android.content.Context;
import android.content.res.Resources;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.TextView;

public class StatusAdapter extends ArrayAdapter<StatusBean> {

    private Context context;
    private ArrayList<StatusBean> statuses;
    public Resources res;
    StatusBean currRowVal = null;
    LayoutInflater inflater;

    public StatusAdapter(Context context,
            int textViewResourceId, ArrayList<StatusBean> statuses,
            Resources resLocal) {
        super(context, textViewResourceId, statuses);
        this.context = context;
        this.statuses = statuses;
        this.res = resLocal;        
        inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    }

    @Override
    public View getDropDownView(int position, View convertView, ViewGroup parent) {
        return getCustomView(position, convertView, parent);
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        return getCustomView(position, convertView, parent);
    }

    public View getCustomView(int position, View convertView, ViewGroup parent) {
        View row = inflater.inflate(R.layout.status_item, parent, false);
        currRowVal = null;
        currRowVal = (StatusBean) statuses.get(position);
        TextView label = (TextView) row.findViewById(R.id.spinnerItem);
        if (position == 0) {
            label.setText("Please select status");
        } else {
            label.setText(currRowVal.getStatus());
        }

        return row;
    }
}

StatusBean class:

public class StatusBean {

    private String status;
    private String statusCode;

    public StatusBean() {
    }

    public StatusBean(String status,
            String statusCode) {
        this.status = status;
        this.statusCode = statusCode;
    }

    public String getStatus() {
        return status;
    }

    public void setStatus(String status) {
        this.status =  status;
    }

    public String getStatusCode() {
        return statusCode;
    }

    public void setStatusCode(String statusCode) {
        this.statusCode = statusCode;
    }
}

活动班级:

在onCreate方法内部:

static ArrayList<StatusBean> STATUS_LIST = new ArrayList<StatusBean>();

for(int i=0;i<=10;i++) {
STATUS_LIST.add(new StatusBean(“Status ”+i, “Stattus ”+i));
}

final Spinner  dropStatus = (Spinner)findViewById(R.id.dropStatus);
            Resources res = getResources(); 
            StatusAdapter adapter = new StatusAdapter(this, R.layout.item, SessionData. STATUS_LIST, res);
            dropStatus.setAdapter(adapter);

在Kotlin中，您可以这样做:

首先，将这些代码放入布局中

   <Spinner
            android:id="@+id/spinner"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"/>

然后你可以在onCreate()在活动作为->

   val spinner = findViewById<Spinner>(R.id.spinner)
    val items = arrayOf("500g", "1kg", "2kg")
    val adapter = ArrayAdapter<String>(
        this,
        android.R.layout.simple_spinner_dropdown_item,
        items
    )
    spinner.setAdapter(adapter)

你可以从下拉菜单中获取listener:

 spinner.onItemSelectedListener = object : OnItemSelectedListener {
        override fun onItemSelected(
            arg0: AdapterView<*>?,
            arg1: View?,
            arg2: Int,
            arg3: Long
        ) {
            // Do what you want
            val items = spinner.selectedItem.toString()
            
        }

        override fun onNothingSelected(arg0: AdapterView<*>?) {}
    }

要将你的列表动态添加到旋转器中，就像从webservice中添加数组列表中的项目，并将其加载到旋转器中

<androidx.appcompat.widget.AppCompatSpinner
    android:id="@+id/catNameSpinner"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:spinnerMode="dropdown"       
    />

    spinner = findViewById(R.id.catNameSpinner);
    ArrayList<String> cat = new ArrayList<>();
    cat.add("Choose");

    ArrayAdapter<String> spinnerAdapter = new ArrayAdapter<String> 
    (this,android.R.layout.simple_dropdown_item_1line,cat);
    spinner.setAdapter(spinnerAdapter);

简单的/优雅的/我怎么做的:

预览:

XML:

<Spinner
    android:id="@+id/spinner1"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="@android:drawable/btn_dropdown"
    android:spinnerMode="dropdown"/>

spinnerMode设置为dropdown是android的下拉方式。(https://developer.android.com/reference/android/widget/Spinner attr_android: spinnerMode)

Java:

//get the spinner from the xml.
Spinner dropdown = findViewById(R.id.spinner1);
//create a list of items for the spinner.
String[] items = new String[]{"1", "2", "three"};
//create an adapter to describe how the items are displayed, adapters are used in several places in android.
//There are multiple variations of this, but this is the basic variant.
ArrayAdapter<String> adapter = new ArrayAdapter<>(this, android.R.layout.simple_spinner_dropdown_item, items);
//set the spinners adapter to the previously created one.
dropdown.setAdapter(adapter);

文档:

这是基础知识，但还有更多的东西可以通过实验自学。 https://developer.android.com/guide/topics/ui/controls/spinner.html

你可以使用setOnItemSelectedListener。(https://developer.android.com/guide/topics/ui/controls/spinner.html # SelectListener) 您可以从xml中添加字符串列表。(https://developer.android.com/guide/topics/ui/controls/spinner.html #填充) 这个视图有一个appCompat版本。(https://developer.android.com/reference/androidx/appcompat/widget/AppCompatSpinner)