vb.net 如何避免在 VB 的 Combobox 中添加重复项？
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How to avoid adding duplicate items in a Combobox in VB?
提问by MattC
I have a Combobox on my form for the user to select items in a drop-down box, also they are allowed to enter their own input. I need the user to add items to a combobox withoutadding a duplicate item already displayed.
我的表单上有一个组合框，供用户在下拉框中选择项目，也允许他们输入自己的输入。我需要用户将项目添加到组合框而不添加已显示的重复项目。
For example: the combobox has a list of dog breeds such as (pug, boxer, pitbull). So how do I not allow the user to enter "pug" when they type that into the combobox?
例如：组合框有一个狗品种列表，例如（哈巴狗、拳击手、比特犬）。那么，当用户在组合框中键入“pug”时，我如何不允许他们输入“哈巴狗”呢？
I'm coding in Visual Basic, Thank You!!!!
我正在用 Visual Basic 编码，谢谢！！！！
回答by Topman
i have tried it. This works.
我试过了。这有效。
And i am only assuming that u want an exceptionwhen duplicated valueis entered. Following is the code and it is in the Combobox1.Validatingevent.
而且我只是假设您在输入重复值时想要一个例外。以下是代码，它位于Combobox1.Validating事件中。
Private Sub ComboBox1_Validating(sender As Object, e As System.ComponentModel.CancelEventArgs) Handles ComboBox1.Validating
For Each item As String In ComboBox1.Items
If item.ToLower.Contains(ComboBox1.Text.ToLower) Then
MsgBox("Duplicate value: there's already '" & item & "' in the list. Please select from the list.", MsgBoxStyle.Exclamation, "Dog Breed")
ComboBox1.Text = ""
Exit For
End If
Next
End Sub
For more information about Validatingevent, search for yourself. Thanks!
有关验证事件的更多信息，请自行搜索。谢谢！
回答by ABDUL MAJEED ALI
Use the code
使用代码
ComboBox1.items.clear()
under your code
在你的代码下
