onListItemClick 中的 getTag() 始终为 null
我有一个 ListView，我用一个 CursorAdapter 填充它，如下所示：
SimpleCursorAdapter.ViewBinder viewBinder = new SimpleCursorAdapter.ViewBinder() {
public boolean setViewValue(View view, Cursor cursor, int columnIndex) {
if(columnIndex == cursor.getColumnIndex(MyTableColumns._ID))
{
view.setTag(cursor.getInt(columnIndex));
}
// some other stuff
}
};
SimpleCursorAdapter adapter = new SimpleCursorAdapter(this, R.layout.my_item_renderer, cursor, from, to);
adapter.setViewBinder(viewBinder);
目的是从单击的列表项中获取 ID：
@Override
protected void onListItemClick(ListView l, View v, int position, long id) {
Object obj = v.getTag();
int myId = Integer.parseInt(obj.toString());
}
但是，这始终返回 空。我在忽略什么？现在我只是使用隐藏的文本字段，但我想知道我做错了什么。
I have a ListView that I'm populating with a CursorAdapter like this:
SimpleCursorAdapter.ViewBinder viewBinder = new SimpleCursorAdapter.ViewBinder() {
public boolean setViewValue(View view, Cursor cursor, int columnIndex) {
if(columnIndex == cursor.getColumnIndex(MyTableColumns._ID))
{
view.setTag(cursor.getInt(columnIndex));
}
// some other stuff
}
};
SimpleCursorAdapter adapter = new SimpleCursorAdapter(this, R.layout.my_item_renderer, cursor, from, to);
adapter.setViewBinder(viewBinder);
The aim is to get the ID from the list item clicked:
@Override
protected void onListItemClick(ListView l, View v, int position, long id) {
Object obj = v.getTag();
int myId = Integer.parseInt(obj.toString());
}
However this is always returning null. What am I overlooking? For now I'm just using a hidden text field but I'd like to know what I was doing wrong.
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onListItemClick()为您提供一个视图，即列表中的行。ViewBinder将值绑定到该行内的 TextView。因此，您调用setTag()的视图与您调用getTag()的视图不同。您可以扩展 SimpleCursorAdapter，以便可以在正确的视图上调用
setTag()，也可以在onListItemClick()中获取v的第一个子视图code> 并获取其标签。onListItemClick()provides you with a view that is the row in the list.ViewBinderbinds values to the TextViews inside this row. Thus the view you callsetTag()on is not the same as the view you callgetTag()on.You can either extend SimpleCursorAdapter so you can call
setTag()on the correct view, or you can get the first child view ofvinonListItemClick()and get the tag of that.您在设置标签时尝试过这个吗？
Have you tried this when setting your tag?
也许您的“if”语句只是返回 false，因此没有设置任何 Tag 值？
Maybe your "if" statement simply returns false and thus no Tag value gets set?