组合框默认值 [英] combobox default value

问题描述

hi;

我有一个vb.net应用程序，并且有一个组合框，其中应该包含一个显示成员(文本)和一个值成员(整数).

问题是:
我想在加载表单时为该组合框设置默认值，但是在动态创建表单和组合框时没有加载事件.我已经使用了combobox.selectedvalue = 6，但是它不起作用.

注意:我不能使用selectedindex属性，因为有时该值来自数据库表主键，该键与组合框索引不同.

代码:

hi;

I have a vb.net application, and I have a combobox which should contains a display member (text) and a value member (integer).

the problem is:
I want to set a default value to that combobox when the form load but I don''t have a load event as I create the form and the combobox dynamically. i have used the combobox.selectedvalue =6 but it doesn''t work.

note: I can''t use the selectedindex property because sometimes the value comes from a DB table primary key which is not the same as the combobox index.

the code:

Private Sub fill_combo(ByRef combo As ComboBox, ByVal nodes As HashMap)
   Dim comboData = New BindingList(Of KeyValuePair(Of Integer, String))

   nodes.movefirst()
   Do While Not nodes.eof
     If check_atrbValue(nodes.key, nodes.value, "string", "other") Then
       comboData.Add(New KeyValuePair(Of Integer, String)(nodes.key, nodes.value))
     End If
     nodes.movenext()
   Loop
   combo.DataSource = comboData
   combo.ValueMember = "Key"
   combo.DisplayMember = "Value"
   combo.selectedvalue=2
End Sub

推荐答案

您需要在所选值中使用一个值，而不是键.
因此，请使用名称(来自DisplayMember)而不是键.

You need to use a value in the selected value rather than the key.
So use names (from DisplayMember) instead of keys.

在表单加载事件中尝试将此操作写为
combo.text =您的期望值"

Try This on form load event write it
combo.text="Your Desired value"

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