如何在VB.net Combobox中手动插入项目？

I've created a Combobox and the list selections are being populated by a DataTable. I can populate it with no problems, but I need to add a default item for the list before the results from the DataTable appears.

我创建了一个Combobox,列表选择由DataTable填充。我可以毫无问题地填充它,但我需要在显示DataTable的结果之前为列表添加一个默认项。

The list should contain:

该清单应包含:

All Rooms and Facilities
Class Room
Laboratory
PE Facility
THE Facility
Drawing Room
Library

But I'm always getting:

但我总是得到:

I've been using this link as my resources: https://msdn.microsoft.com/en-us/library/aa983551.aspx

我一直在使用此链接作为我的资源:https://msdn.microsoft.com/en-us/library/aa983551.aspx

And here's my code:

这是我的代码:

cboByRoomType.Items.Insert(0, "All Rooms and Facilities")
With cboByRoomType
    .DataSource = tempDTRoomType
    .DisplayMember = "Description"
    .ValueMember = "Room Type ID"
    .SelectedIndex = 0
End With

Also, I already tried to add the default item using the Items in the Properties Window, still no good.

此外,我已经尝试使用属性窗口中的项目添加默认项目,仍然没有好处。

1 个解决方案

#1

Try replacing your first row with this (which probably has a more compact form):

尝试用这个替换你的第一行(可能有一个更紧凑的形式):

    tempDTRoomType.Rows.InsertAt(tempDTRoomType.NewRow(), 0)
    tempDTRoomType.Rows(0).Item("Description") = "All Rooms and Facilities"
    tempDTRoomType.Rows(0).Item("Room Type ID") = 0