如何创建下拉列表?我试过ScrollView,但它不是我所需要的。


当前回答

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);

其他回答

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
        }

}

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/

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) { 

                    } 

                } 
        ); 
    }

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<*>?) {}
    }

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

}