Android - 获取 ListView 项目的 id [特殊情况]

发布于 2024-11-19 19:44:09 字数 1658 浏览 3 评论 0原文

在我的数据库类中有一个返回游标的方法。光标将包含来自不同表的数据：

public Cursor fetchFavTitles() {
    return myDataBase.rawQuery("SELECT rowid as _id, title, fav FROM table1 " +
                                "WHERE fav = 1 UNION ALL " +
            "SELECT rowid as _id, title, fav FROM table2 WHERE fav = 1 UNION ALL " +
            "SELECT rowid as _id, title, fav FROM table3 WHERE fav = 1 UNION ALL " +
            "SELECT rowid as _id, title, fav FROM table4 WHERE fav = 1 UNION ALL " +
            "SELECT rowid as _id, title, fav FROM table5 WHERE fav = 1 UNION ALL " +
            "SELECT rowid as _id, title, fav FROM table6 WHERE fav = 1", null);

}

然后，我使用 SimpleCursorAdapter ca 将 Cursor 附加到 ListView lv ：

Cursor cursor = myDbHelper.fetchTitles(c);
String[] columns = {cursor.getColumnName(1)}; 
int[] columnsLayouts = {R.id.item_title};
ca = new SimpleCursorAdapter(this.getBaseContext(), R.layout.items_layout, cursor,columns , columnsLayouts);
lv = getListView();
lv.setAdapter(ca);

现在，如果我选择 ListView 中的任何项目，我想要引用该项目 id。 我希望 id 从该项目所属的表中检索其他信息。并在其他活动 MsgView 中检索它

我尝试了以下操作：

有一个对单击项目时传递的 id 的引用

传递该值与意图，以便其他活动将使用此传递的值检索所需的数据。

lv.setOnItemClickListener(new OnItemClickListener() {
    public void onItemClick(AdapterViewparent, View view,
        int 位置，长 id) {
        Intent i = new Intent(view.getContext(), MsgView.class);
            i.putExtra("id", (int) id); //
            开始活动（一）；
    }
    });

然而，这并没有奏效。看来我使用的 id 不是该项目的 id ！有什么解决方案或想法吗？

原文

In my DB class have a method that returns a Cursor. the cursor will contain data from different tables:

public Cursor fetchFavTitles() {
    return myDataBase.rawQuery("SELECT rowid as _id, title, fav FROM table1 " +
                                "WHERE fav = 1 UNION ALL " +
            "SELECT rowid as _id, title, fav FROM table2 WHERE fav = 1 UNION ALL " +
            "SELECT rowid as _id, title, fav FROM table3 WHERE fav = 1 UNION ALL " +
            "SELECT rowid as _id, title, fav FROM table4 WHERE fav = 1 UNION ALL " +
            "SELECT rowid as _id, title, fav FROM table5 WHERE fav = 1 UNION ALL " +
            "SELECT rowid as _id, title, fav FROM table6 WHERE fav = 1", null);

}

Then, I use a SimpleCursorAdapter ca to attach the Cursor to a ListView lv :

Cursor cursor = myDbHelper.fetchTitles(c);
String[] columns = {cursor.getColumnName(1)}; 
int[] columnsLayouts = {R.id.item_title};
ca = new SimpleCursorAdapter(this.getBaseContext(), R.layout.items_layout, cursor,columns , columnsLayouts);
lv = getListView();
lv.setAdapter(ca);

Now, if I select any item in the ListView, I want to have a reference to that item id.
I want the id to retrieve other information from the table the item belong to. And retrieve it in other activity MsgView

I tried this:

have a reference to the id passed when an item clicked

pass that value with the intent, so that the other activity will retrieve the needed data using this passed value.

lv.setOnItemClickListener(new OnItemClickListener() {
    public void onItemClick(AdapterView<?> parent, View view,
        int position, long id) {
        Intent i = new Intent(view.getContext(), MsgView.class);
            i.putExtra("id", (int) id); //
            startActivity(i);
    }
    });

However, this didn't work. It seems that the id I'm using is not the item's id !
Any solution or ideas ?

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╰◇生如夏花灿烂 2024-11-26 19:44:09

在 onItemClick 方法中尝试这个...

final SimpleCursorAdapter simpleCursorAdapter = (SimpleCursorAdapter) parent.getAdapter();
final Cursor cursor = simpleCursorAdapter .getCursor();

final int idColIndex = cursor.getColumnIndex(KEY_ROWID); //_id column of your table
final int rowId = cursor.getInt(idColIndex);

在我的一个项目中使用的是链接引用第 41 行。希望有所帮助。

编辑：

已解决。见评论。

In onItemClick method try this...

final SimpleCursorAdapter simpleCursorAdapter = (SimpleCursorAdapter) parent.getAdapter();
final Cursor cursor = simpleCursorAdapter .getCursor();

final int idColIndex = cursor.getColumnIndex(KEY_ROWID); //_id column of your table
final int rowId = cursor.getInt(idColIndex);

Used in one of my project here is link refer line number 41. Hope this help.

Edit:

Solved. See comments.

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初吻给了烟 2024-11-26 19:44:09

您想要位置参数而不是 id

请参阅 onItemClick 的文档：

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

自：API 级别 1 单击此 AdapterView 中的项目时将调用回调方法。

如果实施者需要访问与所选项目关联的数据，则可以调用 getItemAtPosition(position)。

参数

parent：单击发生的 AdapterView。
view：被单击的 AdapterView 中的视图（这将是适配器提供的视图）
位置：视图在适配器中的位置。
id：被单击的项目的行 ID。

You want the position parameter not the id

See the documentation of onItemClick:

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

Since: API Level 1 Callback method to be invoked when an item in this AdapterView has been clicked.

Implementers can call getItemAtPosition(position) if they need to access the data associated with the selected item.

Parameters

parent: The AdapterView where the click happened.
view: The view within the AdapterView that was clicked (this will be a view provided by the adapter)
position: The position of the view in the adapter.
id: The row id of the item that was clicked.

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