获取ListView项ID从ListAdapter的行ID [英] Getting ListView item ID from its ListAdapter's row ID

问题描述

我想创建一个单项选择题（例如，单选按钮），这些从数据库中查询到的产品清单。与当前所选行工作，我需要使用 getCheckedItemPosition的ListView（）和 setItemChecked（）方法。

I am trying to create a single-choice (e.g., radio button) list of items that are queried from a database. To work with the currently selected row, I need to use the getCheckedItemPosition() and setItemChecked() methods of ListView.

我有一个的ListView ，有一个设置就可以了 SimpleCursorAdapter 。当我检索当前选定的项目，我有它的行ID 从数据库中，我需要使用找到合适的项目，并手动将其设置为可通过上述方法选择。换句话说，我需要行ID的状态映射到一定单调行ID（因为 setItemChecked（）方法接受一个位置ID，而不是数据库行ID ，并在我的数据库，我可以删除项目）。

I have a ListView that has a SimpleCursorAdapter set on it. When I retrieve the currently selected item, I have its row ID from the database, which I need to use to find the appropriate item and manually set it to be selected via the aforementioned methods. In other words, I need to map the status of a row ID to a necessarily monotonic row ID (because the setItemChecked() method accepts a position ID, not a database row ID, and in my database I can remove items).

那么，有没有办法可以从表行ID的位置ID？我宁愿不诉诸做的，如果可能的搜索。

So is there a way I can get a position id from a table row id? I'd rather not resort to doing a search if possible.

感谢。

推荐答案

我最终只是创造，通过所有的项目搜索（这被认为是按顺序）一个简单的方法：

I ended up just creating a simple method that searches through all the items (which are assumed to be in order):

/**
 * Since Android apparently provides no way to do this, do a simple binary
 * search for the item position based on its row id.
 * @param adapter    The adapter to use
 * @param row    The rowId to search for
 * @param left
 * @param right
 * @return    Position, or -1 if not found
 */
public int getPositionFromRowId(ListAdapter adapter, long row, int left, int right) {
    if (left > right)
        return -1;
    int middle = (left + right) / 2;
    if (adapter.getItemId(middle) == row)
        return middle;
    if (adapter.getItemId(middle) > row)
        return getPositionFromRowId(adapter, row, left, middle - 1);
    else
        return getPositionFromRowId(adapter, row, middle + 1, right);
}

编辑：做这样的事情，请使用此code：

Use this code by doing something like this:

getPositionFromRowId(myListAdapter, row, 0, myListAdapter.getCount());

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