檢索在微調器中挑選的對象

Question

所以我查看了微調API，但它說我使用AdapterView事件處理，但我從來沒有創建一個適應。我在string.xml中創建了數組，然後使用 Android進行檢索：條目= @ array/arrayname

那麼，如何在沒有創建適配器的情況下檢索用戶在微調器中選擇的內容？或者我看着這個錯誤？

Answer 1

谷歌是指通過實施適配器視圖什麼是你必須實現你的活動，例如其OnItemSelectedListener接口：

public class SpinnerActivity extends Activity implements AdapterView.OnItemSelectedListener { 
    ... 

    public void onItemSelected(AdapterView<?> parent, View view, 
      int pos, long id) { 
     // An item was selected. You can retrieve the selected item using 
     // parent.getItemAtPosition(pos) 
    } 

    public void onNothingSelected(AdapterView<?> parent) { 
     // Another interface callback 
    } 
} 

，你必須設置的事件偵聽器是微調爲：

Spinner spinner = (Spinner) findViewById(R.id.spinner); 
spinner.setOnItemSelectedListener(this); 

這裏有一個完整的例子：

MainActivity

public class MainActivity extends Activity implements AdapterView.OnItemSelectedListener { 

    //Spinner 
    private Spinner spinner; 
    //The array that will store the spinner items 
    private ArrayList<String> list; 

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

     //Create the spinner and add its listener 
     spinner = (Spinner)findViewById(R.id.spinner); 
     spinner.setOnItemSelectedListener(this); 

     //Spinner items, stored as a String array 
     list = new ArrayList<>(); 
     list.add("Item 1"); 
     list.add("Item 2"); 
     list.add("Item 3"); 
     list.add("Item 4"); 

     //To populate the spinner with a list of choices, you need to specify a SpinnerAdapter in your Activity or Fragment 
     ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_dropdown_item, list); 
     //Set the adapter to the spinner 
     spinner.setAdapter(adapter); 


    } 

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

     //To Get the selected item: 
     //Since the spinner items are stored inside an array 
     //we can get the selected item text such as item.get(position) 
     Toast.makeText(this, list.get(position), Toast.LENGTH_LONG).show(); 
    } 

activity_main XML佈局

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

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

</LinearLayout>