如何在Android中向微调器中添加项？

Question

如何将项目添加到微调器？

Answer 1

XML文件:

<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);
    }
}

请参见微调器示例.

Answer 2

我找到了另一个选项: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

Answer 3

试试这段代码:

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文件添加微调器项值.

<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
        }
    });

Answer 4

要在Spinner中添加项目,您可以做一件事,尝试创建一个适配器,然后在适配器中添加/删除项目,然后您可以使用setAdapter()方法轻松地将该适配器绑定到微调器.

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);

Answer 5

<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"
    />

Answer 6

此代码基本上读取JSON数组对象,并将每行转换为作为参数传递的微调器中的选项:

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;       
}