如何在Android中向微调器添加项目？

如何将项目添加到微调器？

XML档案：

<Spinner
    android:id="@+id/Spinner01"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"/>

Java文件：

public class SpinnerExample extends Activity {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        String[] arraySpinner = new String[] {
            "1", "2", "3", "4", "5", "6", "7"
        };
        Spinner s = (Spinner) findViewById(R.id.Spinner01);
        ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
                android.R.layout.simple_spinner_item, arraySpinner);
        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        s.setAdapter(adapter);
    }
}

请参阅微调器示例。

我找到了另一个选择：布局文件中的微调器定义

<Spinner android:id="@+id/spinner"
    android:layout_width="fill_parent"
    android:drawSelectorOnTop="true"
    android:prompt="@string/spin"
    android:entries="@array/spinnerItems"
/>

文件array.xml中的项目定义：

<resources>
    <string-array name="spinnerItems">
        <item>item1</item>
        <item>item2</item>
        <item>item3</item>
        <item>item4</item>
    </string-array>
</resources>

链接到完整的代码源

试试这个代码：

final List<String> list = new ArrayList<String>();
list.add("Item 1");
list.add("Item 2");
list.add("Item 3");
list.add("Item 4");
list.add("Item 5");

final String[] str = {"Report 1", "Report 2", "Report 3", "Report 4", "Report 5"};

final Spinner sp1 = (Spinner) findViewById(R.id.spinner1);
final Spinner sp2 = (Spinner) findViewById(R.id.spinner2);

ArrayAdapter<String> adp1 = new ArrayAdapter<String>(this,
                              android.R.layout.simple_list_item_1, list);
adp1.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
sp1.setAdapter(adp1);

ArrayAdapter<String> adp2 = new ArrayAdapter<String>(this,
                                  android.R.layout.simple_spinner_item, str);
adp2.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
sp2.setAdapter(adp2);

sp1.setOnItemSelectedListener(new OnItemSelectedListener()
    {
        @Override
        public void onItemSelected(AdapterView<?> arg0, View arg1, int position, long id) {
            // TODO Auto-generated method stub
            Toast.makeText(getBaseContext(), list.get(position), Toast.LENGTH_SHORT).show();
        }

        @Override
        public void onNothingSelected(AdapterView<?> arg0) {
            // TODO Auto-generated method stub
        }
    });

sp2.setOnItemSelectedListener(new OnItemSelectedListener()
    {
        @Override
        public void onItemSelected(AdapterView<?> arg0, View arg1, int position, long id) {
            // TODO Auto-generated method stub
            Toast.makeText(getBaseContext(), str[position], Toast.LENGTH_SHORT).show();
        }

        @Override
        public void onNothingSelected(AdapterView<?> arg0) {
            // TODO Auto-generated method stub
        }
    });

您还可以通过String数组xml文件添加微调项值。

<resources>
    <string name="app_name">Spinner_ex5</string>
    <string name="hello_world">Hello world!</string>
    <string name="menu_settings">Settings</string>
    <string name="title_activity_main">MainActivity</string>
    <string-array name="str2">
        <item>Data 1</item>
        <item>Data 2</item>
        <item>Data 3</item>
        <item>Data 4</item>
        <item>Data 5</item>
    </string-array>
</resources>

在mainActivity.java中：

final Spinner sp3 = (Spinner) findViewById(R.id.spinner3);
ArrayAdapter<CharSequence> adp3 = ArrayAdapter.createFromResource(this,
                                    R.array.str2, android.R.layout.simple_list_item_1);

adp3.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
sp3.setAdapter(adp3);
sp3.setOnItemSelectedListener(new OnItemSelectedListener()
    {
        @Override
        public void onItemSelected(AdapterView<?> arg0, View arg1, int position, long id) {
            // TODO Auto-generated method stub
            String ss = sp3.getSelectedItem().toString();
            Toast.makeText(getBaseContext(), ss, Toast.LENGTH_SHORT).show();
        }

        @Override
        public void onNothingSelected(AdapterView<?> arg0) {
            // TODO Auto-generated method stub
        }
    });

要在Spinner中添加项目，您可以做一件事，尝试创建适配器，然后将项目添加/删除到适配器中，然后可以使用setAdapter()方法轻松地将该适配器绑定到Spinner 。

这是一个例子：

spinner.setAdapter(adapter);
adapter.add(item1);
adapter.add(item2);
adapter.add(item3);
adapter.add(item4);
adapter.add(item5);
adapter.notifyDataSetChanged();
spinner.setAdapter(adapter);

<string-array name="array_name">
<item>Array Item One</item>
<item>Array Item Two</item>
<item>Array Item Three</item>
</string-array>

在您的布局中：

<Spinner 
        android:id="@+id/spinner"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:drawSelectorOnTop="true"
        android:entries="@array/array_name"
    />

这段代码基本上读取JSON数组对象，并将每一行转换为微调器中作为参数传递的选项：

public ArrayAdapter<String> getArrayAdapterFromArrayListForSpinner(ArrayList<JSONObject> aArrayList, String aField)
{
    ArrayAdapter<String> aArrayAdapter = new ArrayAdapter<String>(context, android.R.layout.simple_spinner_item);
    aArrayAdapter.setDropDownViewResource(R.layout.multiline_spinner_dropdown_item); //android.R.layout.simple_spinner_dropdown_item
    try {
        for (int i = 0; i < aArrayList.size(); i++)
        {
            aArrayAdapter.add(aArrayList.get(i).getString(aField)); 
        }
    } catch (JSONException e) {
        e.printStackTrace();
        ShowMessage("Error while reading the JSON list");
    }
    return aArrayAdapter;       
}

将微调器添加到XML布局，然后将此代码添加到Java文件：

Spinner spinner;
spinner = (Spinner) findViewById(R.id.spinner1) ;
java.util.ArrayList<String> strings = new java.util.ArrayList<>();
strings.add("Mobile") ;
strings.add("Home");
strings.add("Work");
SpinnerAdapter spinnerAdapter = new SpinnerAdapter(AddMember.this, R.layout.support_simple_spinner_dropdown_item, strings);
spinner.setAdapter(spinnerAdapter);

更新列表后添加此代码

假设：

ArrayAdapter <String>变量名是dataAdapter，而List变量名是keys。

• dataAdapter.addAll（keys）;
• dataAdapter.notifyDataSetChanged（）;

要将其他项目添加到Spinner中，您可以：

ArrayAdapter myAdapter = 
  ((ArrayAdapter) mySpinner.getAdapter());

myAdapter.add(myValue);

myAdapter.notifyDataSetChanged();

只是清除适配器，添加所有itens并通知更改，如下所示：

  public void show(List<Object> objLIst) {
    adapter.clear();
    adapter.addAll(objLIst);
    adapter.notifyDataSetChanged(); }

一种更简单的方法是使用材料微调器库：https : //github.com/jaredrummler/MaterialSpinner

首先添加到您的项目：

compile 'com.jaredrummler:material-spinner:1.2.4'

并像这样使用：

<com.jaredrummler.materialspinner.MaterialSpinner
    android:id="@+id/spinner"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"/>

和Java代码，您可以轻松地在Java中添加项目：

MaterialSpinner spinner = (MaterialSpinner) findViewById(R.id.spinner);
spinner.setItems("item 1", "item 2", "item 3", "item 4", "item 5");
spinner.setOnItemSelectedListener(new MaterialSpinner.OnItemSelectedListener<String>() {

  @Override public void onItemSelected(MaterialSpinner view, int position, long id, String item) {
    Snackbar.make(view, "Clicked " + item, Snackbar.LENGTH_LONG).show();
  }
});