java - 如何按位置从Listview中删除项目？

Question

有什么方法可以通过仅知道位置来从 listView 中删除项目吗？它是 listview 或 adapter 的属性吗？请看下图，它演示了 ListView 的可用属性

Updat_1

问题仍然存在。我使用从 SQlite DataBase 检索的数据填充 Listview。检索到的数据以 Array 形式从 String[]retrieveMPLNames() 返回，然后我将此 Array 转换为 ArrayList > 然后将ArrayList 绑定(bind)到ArrayAdapter。当我想要删除时，首先，我从 SQlite DataBase 中删除该项目，然后再次执行相同的过程，即调用 String[]retrieveMPLNames() 这将从SQlite DataBase检索可用数据，返回的Array将转换为ArrayList，然后将其绑定(bind)到ArrayAdapter >。但是，该项目永远不会从 ListView 中删除。请参阅下面的代码。

Java_Code:

if (isDBEmpty()) {
        Log.i(TAG, "@onCreate(): The DataBase Is Empty");
    }else {
        Log.i(TAG, "@onCreate(): The DataBase Is Not Empty");

        bindArrayListToArrayAdapter(arrayToArrayList(retrieveMPLNames()));
    ....
    ....
protected void deleteItemFromDataBase(int itemClickedPos) {
    // TODO Auto-generated method stub
    Log.i(TAG, "@deleteItemFromDataBase():");
    if(! sqliteDB.isOpen()) {
        //mplOpenHelperDB = new MPLDataBase(getApplicationContext());
        sqliteDB = mplOpenHelperDB.getWritableDatabase();
        Log.i(TAG, "@deleteItemFromDataBase(): The Database was closed And Now It Is Opened");
    }
    String locName = mplOpenHelperDB.getLocationName((itemClickedPos+1));
    int []x = mplOpenHelperDB.getIDs();
    Log.i(TAG, "@deleteItemFromDataBase(): total rows in the database = "+mplOpenHelperDB.getCurrentRowNumber());
    Log.i(TAG, "@deleteItemFromDataBase(): name to delete from database = "+locName);
    Log.i(TAG, "@deleteItemFromDataBase(): ID of the item to delete from the database= "+x[itemClickedPos+1]);

    mplOpenHelperDB.deleteRow((itemClickedPos+1));
    Log.i(TAG, "@deleteItemFromDataBase(): total rows in the database after delete = "+mplOpenHelperDB.getCurrentRowNumber());

    notifyArrayAdapter();
}

private void notifyArrayAdapter() {
    // TODO Auto-generated method stub
    Log.i(TAG, "@notifyArrayAdapter(): ");
    mArrayAdapter = new ArrayAdapter<String>(getApplicationContext(), R.layout.savedlocationlist_layout, 
            R.id.savedLocationName, arrayToArrayList(retrieveMPLNames()));
    mListView.setAdapter(mArrayAdapter);
    mArrayAdapter.notifyDataSetChanged();
}
private String [] retrieveMPLNames() {
    // TODO Auto-generated method stub
    Log.d(TAG, "@retrieveMPLNames(): Retrieving MPLNames");

    if (! sqliteDB.isOpen()) { 
        Log.d(TAG, "@retrieveMPLNames(): Your DataBase Was Closed And It Will Be Opened Now");
        sqliteDB = mplOpenHelperDB.getWritableDatabase();
    }

    Log.d(TAG, "@retrieveMPLNames(): Your DataBase Is Opened");
    int []dbIDs = mplOpenHelperDB.getIDs();

    String []str = new String[dbIDs.length];
        for(int i=0; i<dbIDs.length; i++) {
            str[i] = mplOpenHelperDB.getLocationName(dbIDs[i]);
            Log.d(TAG, "@retrieveMPLNames(): "+str[i]);
            Log.d(TAG, "@retrieveMPLNames(): Total Rows Retrieved = "+str.length);
        }
        return str;
    }

Answer 1

您需要从基础数据(即数组、游标等)中删除该项目，然后更新 ListView 以反射(reflect)更改。