将数据加载到 DataGridViewComboBoxColumn VB.NET
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Load data into DataGridViewComboBoxColumn VB.NET
提问by slister
Hi I have been banging my head against the wall all day trying to figure this out.
嗨，我整天都在用头撞墙，试图弄清楚这一点。
I have a DataGridView that is displaying the results of an SQL Query
我有一个显示 SQL 查询结果的 DataGridView
The query returns 3 fields: GROUPNUM, GROUPNAME, COACHING
查询返回 3 个字段：GROUPNUM、GROUPNAME、COACHING
The group fields just have strings in them and they are displaying fine, but the COACHING field is a single character field that will either have a Y or an N in it. For that column I want to have a combobox with Y or N as the items. Here is what I have so far.
组字段中只有字符串并且显示正常，但 COACHING 字段是一个单字符字段，其中将包含 Y 或 N。对于该列，我想要一个带有 Y 或 N 作为项目的组合框。这是我到目前为止所拥有的。
dtGroups is a data table that was filled with an SQL data adapter.
dtGroups 是一个填充了 SQL 数据适配器的数据表。
dvGroups = dtGroups.DefaultView
'Set up datagrid view
With dgvToPopulate
.Columns.Clear()
.AutoGenerateColumns = False
.AutoSizeColumnsMode = DataGridViewAutoSizeColumnsMode.AllCells
.AutoSizeRowsMode = DataGridViewAutoSizeRowsMode.AllCells
.DataSource = dtGroups
With .Columns
Dim groupNumColumn, groupNameColumn As New DataGridViewTextBoxColumn
With groupNumColumn
.DataPropertyName = "GROUPNUM"
.HeaderText = "Group Number"
.ReadOnly = True
End With
With groupNameColumn
.DataPropertyName = "GROUPNAME"
.HeaderText = "Group Name"
.ReadOnly = True
End With
Dim coachingColumn As New DataGridViewComboBoxColumn
With coachingColumn
.HeaderText = "RN Coaching"
.Items.AddRange({"Y", "N"})
.DataPropertyName = "COACHING"
.DisplayMember = .DataPropertyName
.ValueMember = .DisplayMember
End With
.AddRange({groupNumColumn, groupNameColumn, coachingColumn})
End With
End With
The grid is set up the way I want and it is displaying the all the data except all the comboBoxes have nothing selected. How do I get the comboBox to have a Y or N in them based on what was stored in that field.
网格按照我想要的方式设置，它显示所有数据，除了所有组合框都没有选择任何内容。如何根据该字段中存储的内容让组合框在其中包含 Y 或 N。
Any help with this would be appreciated.
对此的任何帮助将不胜感激。
回答by Bj?rn-Roger Kringsj?
Both DisplayMemberand ValueMemberare linked to the DataSourceproperty. Whenever you change one of these properties, the data connection is reset. In other words: the items-collection is cleared.
双方DisplayMember并ValueMember链接到DataSource属性。无论何时更改这些属性之一，都会重置数据连接。换句话说：items-collection 被清除了。
Take your example for instance. The Stringclass do not have a member named COACHING. It has properties like Lengthand Charsetc. So you cannot create a binding. Also, the items-collection accepts all kinds of objects.
以你的例子为例。该String班没有一个名为成员COACHING。它有样特性Length和Chars等，所以您不能创建一个具有约束力。此外，items-collection 接受各种对象。
You need to create and bind a custom data source. Here's an example using a DataTable:
您需要创建和绑定自定义数据源。这是使用 a 的示例DataTable：
Dim ynTable As New DataTable()
With ynTable
.Columns.Add("Value", GetType(String))
.Rows.Add("Y")
.Rows.Add("N")
.AcceptChanges()
End With
With coachingColumn
.HeaderText = "RN Coaching"
.DataSource = ynTable
.DataPropertyName = "COACHING"
.DisplayMember = "Value"
.ValueMember = "Value"
End With
