Question

Dim states As Collection = New Collection()

Sub Output(Value As String)

    txtOutput.Text += Value + vbCrLf

End Sub

Sub ClearOutput(sender As Object, e As RoutedEventArgs) Handles btnClear.Click
    txtOutput.Text = ""
    txtInput.Text = ""
    states.Clear()
End Sub

Sub btnAdd_Click(sender As Object, e As RoutedEventArgs) Handles btnAdd.Click

    Dim input As String = txtInput.Text

    states.Add(input)
    Output("You added: " + input)

End Sub

Private Sub btnGet_Click(sender As Object, e As RoutedEventArgs) Handles btnGet.Click

    Dim counter As Integer = 1
    Dim stateID As String = txtInput.Text.ToString

    If CStr(states.Count) = 0 Then
        Output("Not found")
    End If

    For Each state As String In states
        If states(counter).Contains(stateID) Then
            If Not states(counter).Contains(",") Then
                Output("Add a valid state entry e.g. California, CA")
                Exit For
            End If
            Dim stateOnly = states(counter).Substring(0, state.IndexOf(","))
            Output("You requested: " + states(counter))
            Exit For

        End If

        counter = counter + 1
        If counter > CStr(states.Count) Then
            Output("Not found")
        End If
    Next

End Sub

Private Sub btnRemove_Click(sender As Object, e As RoutedEventArgs) Handles btnRemove.Click

    Dim counter As Integer = 1
    Dim stateID As String = txtInput.Text.ToString
    Dim firstCount As Integer = CStr(states.Count)

    If CStr(states.Count) = 0 Then
        Output("Not found")
    End If
    For Each state As String In states
        If states(counter).Contains(stateID) Then
            If Not states(counter).Contains(",") Then
                Output("Add a valid state entry e.g. California, CA")
                Exit For
            End If
            states.Remove(counter)
            txtOutput.Text = ""

            Dim secondCount As Integer = CStr(states.Count)

            If secondCount < firstCount And secondCount > 0 Then
                counter = 0
                Output(stateID + " removed; here's what's left:")
                OutputStates()
                Exit For
            End If
            If secondCount = 0 Then
                Output("Nothing left.")

            End If
        End If

        counter = counter + 1
        If counter > CStr(states.Count) Then
            Output("Not found")
        End If
    Next

End Sub

Sub btnShow_Click(sender As Object, e As RoutedEventArgs) Handles btnShow.Click
    If CStr(states.Count) = 0 Then
        Output("No entries yet")
    End If
    OutputStates()
End Sub

Sub OutputStates()
    For Each state As String In states
        Output(state)
    Next
End Sub

我已经尝试过以下代码，但它不起作用。我在Sub OutputStates（）上有一个错误，当使用字典时，输出（状态）不再起作用。我想我需要修改输入，进入stateID和stateName，但我不知道如何

Dim states As Dictionary(Of String, String) _
    = New Dictionary(Of String, String)

Sub Output(Value As String)

    txtOutput.Text += Value + vbCrLf

End Sub

Sub ClearOutput(sender As Object, e As RoutedEventArgs) Handles btnClear.Click
    txtOutput.Text = ""
    txtInput.Text = ""
    states.Clear()
End Sub

Sub btnAdd_Click(sender As Object, e As RoutedEventArgs) Handles btnAdd.Click

    Dim input As String = txtInput.Text
    Dim length As Integer = input.Length - 1
    Dim stateID As String = input.Substring(0, 1)
    Dim stateName As String = input.Substring(2, length)

    states.Add(stateID, stateName)
    Output("You added: " + input)

End Sub

Private Sub btnGet_Click(sender As Object, e As RoutedEventArgs) Handles btnGet.Click

    Dim counter As Integer = 1
    Dim stateID As String = txtInput.Text.ToString

    If CStr(states.Count) = 0 Then
        Output("Not found")
    End If

    For Each state In states
        If states(counter).Contains(stateID) Then
            If Not states(counter).Contains(",") Then
                Output("Add a valid state entry e.g. California, CA")
                Exit For
            End If
            Dim stateOnly = states(counter).Substring(0, states(counter).IndexOf(","))
            Output("You requested: " + states(counter))
            Exit For

        End If

        counter = counter + 1
        If counter > CStr(states.Count) Then
            Output("Not found")
        End If
    Next

End Sub

Private Sub btnRemove_Click(sender As Object, e As RoutedEventArgs) Handles btnRemove.Click

    Dim counter As Integer = 1
    Dim stateID As String = txtInput.Text.ToString
    Dim firstCount As Integer = CStr(states.Count)

    If CStr(states.Count) = 0 Then
        Output("Not found")
    End If
    For Each state In states
        If states(counter).Contains(stateID) Then
            If Not states(counter).Contains(",") Then
                Output("Add a valid state entry e.g. California, CA")
                Exit For
            End If
            states.Remove(counter)
            txtOutput.Text = ""

            Dim secondCount As Integer = CStr(states.Count)

            If secondCount < firstCount And secondCount > 0 Then
                counter = 0
                Output(stateID + " removed; here's what's left:")
                OutputStates()
                Exit For
            End If
            If secondCount = 0 Then
                Output("Nothing left.")

            End If
        End If

        counter = counter + 1
        If counter > CStr(states.Count) Then
            Output("Not found")
        End If
    Next

End Sub

Sub btnShow_Click(sender As Object, e As RoutedEventArgs) Handles btnShow.Click
    If CStr(states.Count) = 0 Then
        Output("No entries yet")
    End If
    OutputStates()
End Sub

Sub OutputStates()
    For Each state In states
        Output(states)
    Next
End Sub

Answer 1

在您的Sub outputStates中，您尝试遍历您的状态，但现在这是一个字典而不是普通的集合。

对于循环字典，您可以使用键值对：

Sub OutputStates()
For Each state As KeyValuePair(Of String, String) In states
    Output(state.key)
    Output(state.value)
Next

End Sub

关于分割CA, California：

的其他问题

如果您假设键和值之间的分割是逗号：

Dim splitString as String = "CA, California"
Dim key As String = splitString.Split(",")(0).trim()
Dim value As String = splitString.Split(",")(1).trim()

VB.net如何将此状态集合输入转换为字典键值输入表单

1 个答案: