Question

我在视图中有一个微调器和一个列表视图。数据来自sqlite。 spinner数据来自类别表（Cid，Cname）Cname是在spinner中显示的，listview数据来自Items表（Iid，Iname，Cid）Iname是在listview中显示的。 cid是项目表中的外键。当微调器选择更改时，我想更改列表视图数据。这是我到目前为止所做的... 下面是我的微调器，其中Cname是从sqlite填充的

      spinner1.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
        @Override
        public void onItemSelected(AdapterView<?> parent, View view, final int position, long id) {                                                    dbRepo = new DBRepo(getApplicationContext());                    
            String pos = (String) parent.getSelectedItemPosition();              
            String cid =   dbRepo.getId(pos);
            Toast.makeText(getApplicationContext(), cid, Toast.LENGTH_LONG).show();
            final ArrayList<Support> list = dbRepo.getItems(cid);

                adapter = new Custom(Category.this, R.layout.view_entry, list);

                lv.setAdapter(adapter);                  
               adapter.notifyDataSetChanged();

这是获取微调器中所选项目的cid的代码

public  String getId(String selected) {
    SQLiteDatabase db = this.getReadableDatabase();
    String query = "SELECT Cid from Catogeries where Cname=\"" + selected+ "\"";
    Cursor c = db.rawQuery(query, null);
    String s = null;

    if (c.moveToFirst()) {
        while (c.moveToNext()) {
            s = c.getInt(c.getColumnIndex("Cid"));

        }
    }
    c.close();
    db.close();
    Log.e("CID", " " + s);

    return s;
}

这是从db

获取listview中数据的方法

 public ArrayList<Support> getItems(String cid){
   ArrayList<Support> list = new ArrayList<Support>();
    SQLiteDatabase db = this.getReadableDatabase();
  // Cursor c = db.query(TABLE_ITEM, new String[]{KEY_IID, KEY_INAME, KEY_CID}, KEY_CID + "=?", new String[]{cid}, null, null, null,null);
    String select = "SELECT * from items_table where Cid = "+cid;
    Cursor c = db.rawQuery(select, null);
    String res;
    int j = c.getColumnIndex(Support.KEY_INAME);
    if(c.moveToFirst()){
        do {
            Support item = new Support();
                    item.setItemID(c.getString(0));
                    item.setItemName(c.getString(1));
                    item.setCategoryID(c.getString(2));
                    list.add(item);
        }while (c.moveToNext());
    }
    c.close();
    db.close();
    return list;
}

现在cid正在吐司中显示但是在将cid传递给getitems（）以获取listview.cid中没有显示任何内容的项目在日志中的getItems（）中显示

   public ArrayList<Support> getItems(String cid) {
    ArrayList<Support> itemlist = new ArrayList<Support>();
    SQLiteDatabase db = this.getReadableDatabase();
    Log.e("CID is", cid);
    String selectQuery = "SELECT * FROM " + TABLE_ITEM;
    Cursor c = db.rawQuery(selectQuery, null);
    if (c != null) {
        while (c.moveToNext()) {
            Support item = new Support();
            item.setItemID(c.getString(0));
            item.setItemName(c.getString(1));
            item.setCategoryID(c.getString(2));
            itemlist.add(item);
        }
    }
    c.close();
    db.close();
    return itemlist;
}

上面的代码显示没有传递cid的项目，但是当我通过cid时listview显示为空并且他们在logcat中没有显示错误

终于解决了我的问题，因为cid使用trim函数后的空格，同时将从webservice获取的数据存储到sqlite已经为我做了

Answer 1

public ArrayList<Support> getItems(String cid){
   ArrayList<Support> list = new ArrayList<Support>();
   SQLiteDatabase db = this.getReadableDatabase();

  Cursor cursor = database.rawQuery(SELECT * FROM items_table WHERE Cid =? ",  new String[]  {cid}, null);

   Support item = new Support( ); 
if(cursor!=null)
{
  while(cursor.moveToNext())
{
   String ID= cursor.getString(cursor.getColumnIndexOrThrow(YOUR_DatabaseHelper.id_column));
   // same with the others
   item.add(ID);
   list.add(item);
}
}
    cursor.close();
    db.close();
    return list;
}

如何更改微调器选择的列表视图数据？

1 个答案: