parseInt(binding.inputAge.text.toString()),

新的android资源文件(dropdown_item)在R.layout。Dropdown_item，把textview放在里面。

TextView代码:

`<TextView android:id="@+id/textView"
 android:layout_width="match_parent"
 android:layout_height="wrap_content"
 android:padding="14sp"
 android:text="textView"
 android:textColor="@color/black"
 android:textSize="16sp"
 android:textStyle="bold"
 xmlns:android="http://schemas.android.com/apk/res/android"/>`

//绑定适配器并获取值 binding.ddCity.setAdapter (showCity) binding.ddCity.selectedItem.toString ()

转轮xml:

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

java:

public class MainActivity extends AppCompatActivity implements AdapterView.OnItemSelectedListener{

    private Spinner spinner;
    private static final String[] paths = {"item 1", "item 2", "item 3"};

    @Override
    protected void onCreate(Bundle savedInstanceState){
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main_layout);

        spinner = (Spinner)findViewById(R.id.spinner);
        ArrayAdapter<String>adapter = new ArrayAdapter<String>(MainActivity.this,
                android.R.layout.simple_spinner_item,paths);

        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        spinner.setAdapter(adapter);
        spinner.setOnItemSelectedListener(this);

    }

    @Override
    public void onItemSelected(AdapterView<?> parent, View v, int position, long id) {

        switch (position) {
            case 0:
                // Whatever you want to happen when the first item gets selected
                break;
            case 1:
                // Whatever you want to happen when the second item gets selected
                break;
            case 2:
                // Whatever you want to happen when the thrid item gets selected
                break;

        }
    }

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

}

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)

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<*>?) {}
    }

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);

试试这个…

<string-array name="names">

        <item></item>
        <item>By Bus</item>
        <item>By Train</item>
        <item>By Van</item>
        <item>By Bike</item>
    </string-array>


String travel_type;


ArrayAdapter<String> myAdapter = new ArrayAdapter(AddNew_Trip.this,android.R.layout.simple_list_item_1, getResources().getStringArray(R.array.names)); 
        myAdapter.setDropDownViewResource(android.R.layout.simple_dropdown_item_1line); 
        mySpinner.setAdapter(myAdapter); 

        mySpinner.setOnItemSelectedListener( 
                new AdapterView.OnItemSelectedListener() { 

                    @Override 
                    public void onItemSelected(AdapterView<?> adapterView, View view, int i, long l) { 
                        travel_type = String.valueOf(adapterView.getItemAtPosition(i)); 
                        //Toast.makeText(Plan_Trip.this, travel_type, Toast.LENGTH_SHORT).show(); 
                    } 

                    @Override 
                    public void onNothingSelected(AdapterView<?> adapterView) { 

                    } 

                } 
        ); 
    }