SimpleAdapterを使用してスピナーから選択したアイテムの位置を取得する方法

Question

私は以下のコードを使用して読み込まれたスピナーを持っていますが、スピナーからユーザーが選択したアイテムを取得します。 これにはどのような方法が最適ですか？

List<Map<String, String>> tablelist = new ArrayList<>(); 
    SQLiteDatabase db = openOrCreateDatabase("database", MODE_PRIVATE, null); 
    String query = "select * from table"; 
    Cursor ps = db.rawQuery(query, null); 
    while (ps.moveToNext()){ 
     Map<String, String> datanum = new HashMap<>(); 
     datanum.put("Id", ps.getString(ps.getColumnIndex("Id"))); 
     datanum.put("Some", ps.getString(ps.getColumnIndex("Some"))); 
     tablelist.add(datanum); 
    } 
    db.close(); 
    ps.close(); 
    SimpleAdapter spinnerAdapter = new SimpleAdapter(this, tablelist, R.layout.row_spinner, new String[] {"Id", "Some"}, new int[] {android.R.id.text1, android.R.id.text1}); 
    spinnerAdapter.notifyDataSetChanged(); 
    spinnerAdapter.setDropDownViewResource(R.layout.row_spinner_list); 
    spinner.setAdapter(spinnerAdapter); 

Answer 1

私は疑問にお答えします：「私は（setSelectionに必要なアイテムの位置を取得するための最良の方法）メソッド」私はそれはあなたが求めているものであると思います。

SimpleAdapterをArrayAdapterに変更しました。

あなたはDTBリクエストであるために、結果ごとにオブジェクトを作成し、そのオブジェクトをスピナーにマップすることを推奨します。したがって、各結果に簡単にアクセスできます。このような

：あなたの答えのためのコードの下

public class test { 
    private String TAG = "test"; 

    private Activity curAct; 
    private Spinner spinner; 
    private SpnObj[] spinnerOptions; 

    public test(Activity curAct) { 
     this.curAct = curAct; 
    } 

    public void test() { 
     this.spinner = new Spinner(this.curAct); 
     this.spinnerOptions = this.getSpnContent(); 

     final ArrayAdapter spinnerAdapter = new ArrayAdapter<>(this.curAct, android.R.layout.simple_spinner_item, spinnerOptions); 
     spinnerAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item); 
     this.spinner.setAdapter(spinnerAdapter); 

     // setSelection with item id = 1 
     this.preSelectItem(1); 

     // setSelection with item some = 'some' 
     this.preSelectItem("some"); 

     // get selectedItem 
     SpnObj selectedItem = this.getSelectedItem(); 

     Log.d(TAG, "the current selected item id is : " + selectedItem.id); 
     Log.d(TAG, "the current selected item some is : " + selectedItem.some); 
    } 

    // this method should be used when you need to access on you're selectedItem 
    public SpnObj getSelectedItem() { 
     return (SpnObj) this.spinner.getSelectedItem(); 
    } 

    // this method should be used for set the selection on a item with the id => maybe that was what you're asking for 
    public void preSelectItem(int id) { 
     boolean doWeStopTheLoop = false; 

     for (int i = 0; i < this.spinnerOptions.length && !doWeStopTheLoop; i++) { 
      if (((SpnObj) this.spinner.getItemAtPosition(i)).id == id) { 
       this.spinner.setSelection(i); 
       doWeStopTheLoop = true; //you can use break; too 
      } 
     } 
    } 

    // this method should be used for set the selection on a item with the id => maybe that was what you're asking for 
    // surcharge for 'some' column 
    public void preSelectItem(String some) { 
     boolean doWeStopTheLoop = false; 

     for (int i = 0; i < this.spinnerOptions.length && !doWeStopTheLoop; i++) { 
      if (((SpnObj) this.spinner.getItemAtPosition(i)).some.equals(some)) { 
       this.spinner.setSelection(i); 
       doWeStopTheLoop = true; //you can use break; too 
      } 
     } 
    } 

    private SpnObj[] getSpnContent() {  // this method must be call in a thread 
     SQLiteDatabase db = this.curAct.openOrCreateDatabase("database", 0, null); 
     String query = "select * from table"; 
     Cursor ps = db.rawQuery(query, null); 

     SpnObj[] spnContent = new SpnObj[ps.getColumnCount()]; 

     if (ps.getColumnCount() > 0) { 
      int iterator = 0; 
      while (ps.moveToNext()) { 
       spnContent[iterator] = new SpnObj(
         ps.getInt(ps.getColumnIndex("Id")), 
         ps.getString(ps.getColumnIndex("Some")) 
       ); 

       iterator++; 
      } 
     } else { 
      // no rows : insert code here if you want manage this 
     } 

     db.close(); 
     ps.close(); 

     return spnContent; 
    } 
} 

// this object is only encapsulate the DTB result in a java class, so we can work easily with 
class SpnObj { 
    public int id; 
    public String some; 

    public SpnObj(int id, String some) { 
     this.id = id; 
     this.some = some; 
    } 

    @Override 
    public String toString() {   // important ! this method will be used for display the value in the dropdown list from the spinner 
     return this.some; 
    } 
} 

Answer 2

チェック、あなたは以下のコードでの位置だけでなく、選択した項目を取得することができます。

SimpleAdapter spinnerAdapter = new SimpleAdapter(this, tablelist, R.layout.row_spinner, new String[] {"Id", "Some"}, new int[] {android.R.id.text1, android.R.id.text1}); 
    spinnerAdapter.notifyDataSetChanged(); 
    spinnerAdapter.setDropDownViewResource(R.layout.row_spinner_list); 
    spinner.setAdapter(spinnerAdapter); 

    spinner.setOnItemSelectedListener(new OnItemSelectedListener() 
    { 
     @Override 
     public void onItemSelected(AdapterView<?> parent, View v,int position, long id) 
     { 
      //Here position is selected item position 
      Map<String, String> datanum = tablelist.get(position); 
      // now you can use this datanum for further use 
     } 

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

     } 
    });