VB.Net“掩码”组合框文本作为另一个文本

Question

所以我有一个组合框，其中包含来自 MySql 数据库的表名，它们在表单加载时使用show tables 查询自动列出。

是否无论如何要在组合框中显示其他内容，但文本值仍然是原始表名？

Answer 1

这不是不可能的。这是一个简单的例子：

Public Class Form1

  Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load

    ' This would be whatever you are pulling from the database.  For the purpose of this example, it is just mock data.
    Dim dataFromDatabase As IEnumerable(Of String) = {"1st table from db", "2nd table from db", "etc."}

    ' What you actually want to display in the combobox.  It should be in the same order as above and have the same number of items.  Items must be unique.
    Dim valuesToDisplayInComboBox As IEnumerable(Of String) = {"1st item", "2nd item", "3rd item"}


    ' This is what ties the two together.  You would probably want this to be larger in scope than this example.
    Dim dataCollection As New Dictionary(Of String, String)   
    For i As Integer = 0 To dataFromDatabase.Count - 1 Step 1
      dataCollection.Add(valuesToDisplayInComboBox(i), dataFromDatabase(i))
    Next

    ComboBox1.DataSource = valuesToDisplayInComboBox

  End Sub
End Class

现在您有一个Dictionary 将这两个链接在一起，因此每当用户在组合框中选择某些内容时，您将转到Dictionary 并查找相应的表名。

Answer 2

Class Element
    Public ItemName as String = ""
    Public ItemData As Object = Nothing     
    ' Object allows it to be reusable beyond this use

    Public Sub New(iName as String, iData As Object)
         ItemName = iName
         ItemData = iData
    End Sub

    Public overrides Function ToString As String
       Return ItemName
    End sub
End Class

....

For each s as string in listoftablesfromdatabase
  ' dont know how you are getting your list, 
  ' but here is one way to alias them
  Dim El as Element

  Select Case s
       Case "tbl_event_birthdays_september"
           El = New Element("September Birthdays", s)
       case ...
       case ...
   End Select
   ComboBox1.Items.Add(el)
 Next s

该类将自动使用您给它的友好名称。获取真正的选中项名称：

  realName = ComboBox1.SelectedItem.ItemData.Tostring

可能不需要 .ToString 这与 Douglas Barbin 的想法没有太大不同，它仍然关联 2 个字符串，只是不使用字典。或者，您可以将元素存储在 List(of Element) 或 Dictionary 中，并将其绑定到数据源，如 Douglas 所示。

如果用户一遍又一遍地回到 Combo，那么一定要使用列表或字典，但不是临时的 - 构建一次并一遍又一遍地使用它。