AutoCompleteTextView OnItemClick位置始終爲「0」

Question

適配器工作正常，但我不明白爲什麼在OnItemClick位置始終爲「0」

String[] regions = ct.getRegions(); 
    ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, 
      android.R.layout.simple_dropdown_item_1line, regions); 
    regionT.setAdapter(adapter); 
    regionT.setOnItemClickListener(new OnItemClickListener() { 

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

      // TODO Auto-generated method stub 
       int pos=position; 
     } 
    }); 

Answer 1

不要問我爲什麼，但在方法OnItemClickListener.onItemClick參數position相對AutoCompleteTextView的下拉列表索引持有，不在你的適配器陣列中的位置（在你的案例regions）！

所以，找到該項目的實際position你得在下拉列表中選擇的字符串，找到其索引的轉接器陣列中：

String[] regions = ct.getRegions(); 
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_dropdown_item_1line, regions); 
regionT.setAdapter(adapter); 
regionT.setOnItemClickListener(new OnItemClickListener() { 
    @Override 
    public void onItemClick(AdapterView<?> parent, View view, int position, long id) { 
     String selected = (String) parent.getItemAtPosition(position); 
     int pos = Arrays.asList(regions).indexOf(selected); 
    } 
}); 

Answer 2

我把這個簡單的例子，它能夠正常工作爲了我。請看下圖：

package com.example.autocompletetv; 

import android.app.ListActivity; 
import android.os.Bundle; 
import android.util.Log; 
import android.view.Menu; 
import android.view.View; 
import android.widget.AdapterView; 
import android.widget.AdapterView.OnItemClickListener; 
import android.widget.ArrayAdapter; 

public class AutoCompleteActivity extends ListActivity { 

    public static final String TAG = AutoCompleteActivity.class.getSimpleName(); 

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

     String[] regions = {"One", "Two", "Three", "Four", "Five"}; 
     ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, 
       android.R.layout.simple_dropdown_item_1line, regions); 
     this.setListAdapter(adapter); 

     this.getListView().setOnItemClickListener(new OnItemClickListener() { 

      @Override 
      public void onItemClick(AdapterView<?> parent, View view, int position, long id) { 
       Log.i(TAG, "postion was " + position); 
      } 
     }); 
    } 

    @Override 
    public boolean onCreateOptionsMenu(Menu menu) { 
     // Inflate the menu; this adds items to the action bar if it is present. 
     getMenuInflater().inflate(R.menu.auto_complete, menu); 
     return true; 
    } 

} 

當我點擊我得到：

12-09 19:13:30.617: I/AutoCompleteActivity(1883): postion was 2 
12-09 19:13:31.997: I/AutoCompleteActivity(1883): postion was 3 
12-09 19:13:34.687: I/AutoCompleteActivity(1883): postion was 4 
12-09 19:13:37.028: I/AutoCompleteActivity(1883): postion was 0