如何在android中运行时更新列表视图数据

Question

我有列表视图与从数据库加载数据的复选框。而且我也有一个按钮，当我按下按钮时，微调器弹出2条消息“编辑”和“删除”。删除工作正常。如果我选择编辑选项，然后按确定，然后编辑文本进入警报窗口与两个按钮确定和取消。

现在我想，无论我在编辑文本中输入什么，然后按确定按钮，选择的列表视图数据（选中）应该用新文本更新，无论我在编辑文本中输入了什么内容。那么如何实现这一点。请帮帮我。任何帮助，将不胜感激。提前致谢。

我创建的数据库代码：

public class DataManipulatorClass { 

public static final String KEY_ROWID = "id"; 
private static final String DATABASE_NAME = "mydatabaseclass.db"; 
private static final int DATABASE_VERSION = 1; 
static final String TABLE_NAME = "newtableclass"; 
private static Context context; 
static SQLiteDatabase db; 
OpenHelper openHelper = null; 

private SQLiteStatement insertStmt; 

private static final String INSERT = "insert into " + TABLE_NAME 
     + "(classname) values (?)"; 

public DataManipulatorClass(Context context) { 
    DataManipulatorClass.context = context; 
    OpenHelper openHelper = new OpenHelper(DataManipulatorClass.context); 
    DataManipulatorClass.db = openHelper.getWritableDatabase(); 
    this.insertStmt = DataManipulatorClass.db.compileStatement(INSERT); 
    //this.db = openHelper.getWritableDatabase(); 
} 

public long insert(String classname) { 
    this.insertStmt.bindString(1, classname); 
    return this.insertStmt.executeInsert(); 
} 

public void close() { 
    if (openHelper != null) { 
     openHelper.close(); 
    } 
} 

public void deleteAll() { 
    db.delete(TABLE_NAME, null, null); 
} 

public List<String[]> selectAll() { 
    List<String[]> list = new ArrayList<String[]>(); 
    Cursor cursor = db.query(TABLE_NAME, 
      new String[] { "id", "classname" }, null, null, null, null, 
      "classname asc"); 
    int x = 0; 
    if (cursor.moveToFirst()) { 
     do { 
      String[] b1 = new String[] { cursor.getString(0), 
        cursor.getString(1) }; 
      list.add(b1); 
      x = x + 1; 
     } while (cursor.moveToNext()); 
    } 
    if (cursor != null && !cursor.isClosed()) { 
     cursor.close(); 
    } 
    cursor.close(); 
    return list; 
} 

public boolean delete(long rowId) { 
    /** this method deletes by id, the first column in your database */ 
    return db.delete(TABLE_NAME, KEY_ROWID + "=" + rowId, null) > 0; 
} 

private static class OpenHelper extends SQLiteOpenHelper { 
    OpenHelper(Context context) { 
     super(context, DATABASE_NAME, null, DATABASE_VERSION); 
    } 

    @Override 
    public void onCreate(SQLiteDatabase db) { 
     db.execSQL("CREATE TABLE " + TABLE_NAME 
       + " (id INTEGER PRIMARY KEY, classname TEXT)"); 
    } 

    @Override 
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { 
     db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME); 
     onCreate(db); 
    } 
} 
} 

我的动态类：

public class Classes extends Activity implements OnClickListener { 

ImageView imageViewNewClass, imageViewDelete; 
ListView mListView; 
String[] stg1; 
List<String[]> names2 = null; 
DataManipulatorClass dataManipulator; 
ArrayAdapter<CharSequence> adapterSpinner; 
ArrayAdapter<String> adapter; 

/** Sliding Menu */ 
boolean alreadyShowing = false; 
private int windowWidth; 
private Animation animationClasses; 
private RelativeLayout classesSlider; 
LayoutInflater layoutInflaterClasses; 

@SuppressWarnings("deprecation") 
@Override 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.classes); 

    imageViewNewClass = (ImageView) findViewById(R.id.newclass); 
    imageViewDelete = (ImageView) findViewById(R.id.deletemenu); 
    mListView = (ListView) findViewById(R.id.displaydata); 

    Display display = getWindowManager().getDefaultDisplay(); 
    windowWidth = display.getWidth(); 
    display.getHeight(); 
    layoutInflaterClasses = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE); 

    imageViewDelete.setOnClickListener(new OnClickListener() { 
     @Override 
     public void onClick(View v) { 
      deleteMenuSpinner(); 
     } 

     private void deleteMenuSpinner() { 
      AlertDialog.Builder alertDialog = new AlertDialog.Builder(
        Classes.this); 

      final Spinner spinnerDelete = new Spinner(Classes.this); 
      alertDialog.setView(spinnerDelete); 

      adapterSpinner = ArrayAdapter.createFromResource(Classes.this, 
        R.array.delete_menu, 
        android.R.layout.simple_spinner_item); 
      adapterSpinner 
        .setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item); 
      spinnerDelete.setAdapter(adapterSpinner); 

      alertDialog.setPositiveButton("Ok", 
        new DialogInterface.OnClickListener() { 
         public void onClick(DialogInterface dialog, 
           int which) { 

            Delete operation code..... 
           } 

          } else { 
           AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(
             Classes.this); 
           final EditText updateClass = new EditText(
             Classes.this); 
           LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(
             LinearLayout.LayoutParams.MATCH_PARENT, 
             LinearLayout.LayoutParams.MATCH_PARENT); 
           updateClass.setLayoutParams(lp); 
           alertDialogBuilder.setView(updateClass); 
           alertDialogBuilder 
             .setTitle("Edit Operation"); 
           alertDialogBuilder 
             .setMessage("Enter New Class Name") 
             .setCancelable(false) 
             .setPositiveButton(
               "Yes", 
               new DialogInterface.OnClickListener() { 
                public void onClick(
                  DialogInterface dialog, 
                  int id) { 
                } 
               }) 
             .setNegativeButton(
               "No", 
               new DialogInterface.OnClickListener() { 
                public void onClick(
                  DialogInterface dialog, 
                  int id) { 
                 dialog.cancel(); 
                } 
               }); 
           AlertDialog alertDialog = alertDialogBuilder 
             .create(); 
           alertDialog.show(); 
          } 
         } 
        }); 

      alertDialog.setNegativeButton("Cancel", 
        new DialogInterface.OnClickListener() { 
         public void onClick(DialogInterface dialog, 
           int which) { 
          dialog.cancel(); 
         } 
        }); 
      alertDialog.show(); 
     } 
    }); 

    findViewById(R.id.skirrmenu).setOnClickListener(new OnClickListener() { 
     @Override 
     public void onClick(View v) { 
      if (!alreadyShowing) { 
       alreadyShowing = true; 
       openSlidingMenu(); 
      } 
     } 
    }); 

    imageViewNewClass.setOnClickListener(new View.OnClickListener() { 
     public void onClick(View v) { 
      Intent intent = new Intent(Classes.this, Class_Create.class); 
      startActivity(intent); 
     } 
    }); 

    mListView.setOnItemClickListener(new AdapterView.OnItemClickListener() { 
     public void onItemClick(AdapterView<?> parent, View item, 
       int position, long id) { 
      // Toast.makeText(getApplicationContext(), 
      // "Listview item clicked", Toast.LENGTH_LONG).show(); 

      SparseBooleanArray sp = mListView.getCheckedItemPositions(); 
      StringBuffer str = new StringBuffer(); 
      for (int i = 0; i < sp.size(); i++) { 
       if (sp.valueAt(i) == true) { 
        String s = ((TextView) mListView.getChildAt(i)) 
          .getText().toString(); 
        str = str.append(" " + s); 
       } 
      } 
      Toast.makeText(Classes.this, 
        "Selected items are " + str.toString(), 
        Toast.LENGTH_LONG).show(); 

      // Intent intent = new Intent(Classes.this, PlayAudio.class); 
      // startActivity(intent); 
     } 
    }); 

    dataManipulator = new DataManipulatorClass(this); 
} 

@Override 
protected void onResume() { 
    // TODO Auto-generated method stub 
    super.onResume(); 

    names2 = dataManipulator.selectAll(); 

    stg1 = new String[names2.size()]; 
    int x = 0; 
    String stg; 

    for (String[] name : names2) { 
     stg = "Class Name : " + name[1]; 
     stg1[x] = stg; 
     x++; 
    } 

    adapter = new ArrayAdapter<String>(this, 
      R.layout.custom_list_item_multiple_choice, stg1); 
    mListView.setChoiceMode(ListView.CHOICE_MODE_SINGLE); 
    mListView.setBackgroundResource(R.drawable.assignmentheader); 
    mListView.setCacheColorHint(Color.TRANSPARENT); 
    mListView.setAdapter(adapter); 
    adapter.notifyDataSetChanged(); 
} 

@Override 
protected void onDestroy() { 
    // TODO Auto-generated method stub 
    super.onDestroy(); 
    if (dataManipulator != null) 
     dataManipulator.close(); 
} 
} 

Answer 1

你可以尝试使用adapter.notifyDataSetChanged（）时，OK按钮按下。但它会更新整个列表。如果这是你需要的，那么这就是解决方案。 要更新一个列表项目，你可以试试这个：

private void updateView(int index, String updateText){ 
    View v = yourListView.getChildAt(index - 
     yourListView.getFirstVisiblePosition()); 
    TextView someText = (TextView) v.findViewById(R.id.sometextview); 
    someText.setText(updateText); 
}