我正在尝试在 VB.net 中实现 IDictionary 接口，但出现错误。请帮助我。
Imports System.Collections.Generic
Public Class DataDictionary Implements IDictionary(Of String, Object)
Private _ce As CalcEngine.CalcEngine
Private _dct As Dictionary(Of String, Object)
Public Sub New(ByVal ce As CalcEngine.CalcEngine)
_ce = ce
_dct = New Dictionary(Of String, Object)()
End Sub
#Region "IDictionary<string,object> Members"
Public Sub Add(ByVal key As String, ByVal value As Object) Implements Collections.Generic.IDictionary(Of String, Object).Add
_dct.Add(key, value)
End Sub
Public Function ContainsKey(ByVal key As String) As Boolean Implements System.Collections.Generic.IDictionary(Of String, Object).ContainsKey
Return _dct.ContainsKey(key)
End Function
Public ReadOnly Property Keys() As ICollection(Of String) Implements System.Collections.Generic.IDictionary(Of String, Object).Keys
Get
Return _dct.Keys
End Get
End Property
Public Function Remove(ByVal key As String) As Boolean Implements System.Collections.Generic.IDictionary(Of String, Object).Remove
Return _dct.Remove(key)
End Function
Public ReadOnly Property Values() As ICollection(Of Object) Implements System.Collections.Generic.IDictionary(Of String, Object).Values
Get
Return _dct.Values
End Get
End Property
Public Function TryGetValue(ByVal key As String, ByRef value As Object) As Boolean Implements System.Collections.Generic.IDictionary(Of String, Object).TryGetValue
If _dct.TryGetValue(key, value) Then
Dim expr = TryCast(value, String)
If expr IsNot Nothing AndAlso expr.Length > 0 AndAlso expr(0) = "="c Then
value = _ce.Evaluate(expr.Substring(1))
End If
Return True
End If
Return False
End Function
Default Public Property Item(ByVal key As String) As Object Implements System.Collections.Generic.IDictionary(Of String, Object).Item
Get
Dim value As Object
If TryGetValue(key, value) Then
Return value
End If
Throw New Exception("invalid index")
End Get
Set(ByVal value As Object)
_dct(key) = value
End Set
End Property
#End Region
#Region "ICollection<KeyValuePair<string,object>> Members"
Public Sub Add(ByVal item As KeyValuePair(Of String, Object)) Implements System.Collections.Generic.ICollection(Of KeyValuePair(Of String, Object)).Add
Dim d = TryCast(_dct, ICollection(Of KeyValuePair(Of String, Object)))
d.Add(item)
End Sub
Public Sub Clear() Implements System.Collections.Generic.ICollection(Of KeyValuePair(Of String, Object)).Clear
_dct.Clear()
End Sub
Public Function Contains(ByVal item As KeyValuePair(Of String, Object)) As Boolean Implements System.Collections.Generic.ICollection(Of KeyValuePair(Of String, Object)).Contains
Dim d = TryCast(_dct, ICollection(Of KeyValuePair(Of String, Object)))
Return d.Contains(item)
End Function
Public Sub CopyTo(ByVal array As KeyValuePair(Of String, Object)(), ByVal arrayIndex As Integer) Implements System.Collections.Generic.ICollection(Of KeyValuePair(Of String, Object)).CopyTo
Dim d = TryCast(_dct, ICollection(Of KeyValuePair(Of String, Object)))
d.CopyTo(array, arrayIndex)
End Sub
Public ReadOnly Property Count() As Integer Implements System.Collections.Generic.ICollection(Of KeyValuePair(Of String, Object)).Count
Get
Return _dct.Count
End Get
End Property
Public ReadOnly Property IsReadOnly() As Boolean Implements System.Collections.Generic.ICollection(Of KeyValuePair(Of String, Object)).IsReadOnly
Get
Return False
End Get
End Property
Public Function Remove(ByVal item As KeyValuePair(Of String, Object)) As Boolean Implements System.Collections.Generic.ICollection(Of KeyValuePair(Of String, Object)).Remove
Dim d = TryCast(_dct, ICollection(Of KeyValuePair(Of String, Object)))
Return d.Remove(item)
End Function
#End Region
#Region "IEnumerable<KeyValuePair<string,object>> Members"
Public Function GetEnumerator() As IEnumerator(Of KeyValuePair(Of String, Object)) Implements IEnumerable(Of KeyValuePair(Of String, Object)).GetEnumerator
Return TryCast(_dct.GetEnumerator(), IEnumerator(Of KeyValuePair(Of String, Object)))
End Function
#End Region
#Region "IEnumerable Members"
Private Function GetEnumerator() As System.Collections.IEnumerator Implements System.Collections.IEnumerable.GetEnumerator
Return TryCast(_dct.GetEnumerator(), System.Collections.IEnumerator)
End Function
#End Region
End Class
当我编译得到以下错误：
错误 1 类 'DataDictionary' 必须为接口 'System.Collections.Generic.IEnumerable(Of System.Collections.Generic.KeyValuePair(Of String, Object) 实现 'Function GetEnumerator() As IEnumerator(Of KeyValuePair(Of String, Object))' ))'。H:\Test\WindowsApplication1\WindowsApplication1\ProbeDataDictionary.vb 4 16 WindowsApplication1
错误 3 'Public Function GetEnumerator() As System.Collections.Generic.IEnumerator(Of System.Collections.Generic.KeyValuePair(Of String, Object))' 和 'Private Function GetEnumerator() As System.Collections.IEnumerator' 不能重载每个其他，因为它们仅在返回类型上有所不同。H:\Test\WindowsApplication1\WindowsApplication1\ProbeDataDictionary.vb 96 21 WindowsApplication1
提前致谢。