下拉列表(Spinner)

上一篇文章闡釋了適配器(Adapter), 列表適配器(ListAdapter)和數組適配器(ArrayAdapter), 來看看一個例子.




修改main.xml添加一個Spinner和一個Button.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
<TextView  
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="@string/hello"
    />
<Spinner
    android:id="@+id/spinner"
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    />
<Button
    android:id="@+id/button"
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="Read Day of Week"
    />
</LinearLayout>

然後修改主程序:

public class AndroidSpinner extends Activity {
 
 private static final String[] dayOfWeek =
 {"Sunday", "Monday", "Tuesday", "Wednesday", 
  "Thursday", "Friday", "Saturday"};
 private ArrayAdapter<String> adapter;
 
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        final Spinner mySpinner = (Spinner)findViewById(R.id.spinner);
        Button myButton = (Button)findViewById(R.id.button);
        
        adapter = new ArrayAdapter<String>(this,
          android.R.layout.simple_spinner_item, dayOfWeek);
        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        mySpinner.setAdapter(adapter);
        
        myButton.setOnClickListener(
          new Button.OnClickListener(){

     @Override
     public void onClick(View v) {
      // TODO Auto-generated method stub
      Toast
      .makeText(AndroidSpinner.this, 
      (CharSequence) mySpinner.getSelectedItem(), 
        Toast.LENGTH_LONG)
      .show();
     } 
          });
    }
}

除此之外, 數組適配器(ArrayAdapter)的內容亦可以使用ArrayAdapter.createFromResource(), 通過XML定義.