本文整理汇总了VB.NET中System.Dynamic.DynamicObject.TrySetIndex方法的典型用法代码示例。如果您正苦于以下问题:VB.NET DynamicObject.TrySetIndex方法的具体用法?VB.NET DynamicObject.TrySetIndex怎么用?VB.NET DynamicObject.TrySetIndex使用的例子?那么, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类System.Dynamic.DynamicObject
的用法示例。
在下文中一共展示了DynamicObject.TrySetIndex方法的1个代码示例,这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞,您的评价将有助于系统推荐出更棒的VB.NET代码示例。
示例1: SampleDynamicObject
' The class derived from DynamicObject.
Public Class SampleDynamicObject
Inherits DynamicObject
' The inner dictionary to store field names and values.
Dim dictionary As New Dictionary(Of String, Object)
' Get the property value.
Public Overrides Function TryGetMember(
ByVal binder As System.Dynamic.GetMemberBinder,
ByRef result As Object) As Boolean
Return dictionary.TryGetValue(binder.Name, result)
End Function
' Set the property value.
Public Overrides Function TrySetMember(
ByVal binder As System.Dynamic.SetMemberBinder,
ByVal value As Object) As Boolean
dictionary(binder.Name) = value
Return True
End Function
' Set the property value by index.
Public Overrides Function TrySetIndex(
ByVal binder As System.Dynamic.SetIndexBinder,
ByVal indexes() As Object, ByVal value As Object) As Boolean
Dim index As Integer = CInt(indexes(0))
' If a corresponding property already exists, set the value.
If (dictionary.ContainsKey("Property" & index)) Then
dictionary("Property" & index) = value
Else
' If a property does not exist, create it.
dictionary.Add("Property" & index, value)
End If
Return True
End Function
' Get the property value by index.
Public Overrides Function TryGetIndex(
ByVal binder As System.Dynamic.GetIndexBinder,
ByVal indexes() As Object, ByRef result As Object) As Boolean
Dim index = CInt(indexes(0))
Return dictionary.TryGetValue("Property" & index, result)
End Function
End Class
Sub Test()
' Creating a dynamic object.
Dim sampleObject As Object = New SampleDynamicObject()
' Creating Property0.
' The TrySetMember method is called.
sampleObject.Property0 = "Zero"
' Getting the value by index.
' The TryGetIndex method is called.
Console.WriteLine(sampleObject(0))
' Setting the property value by index.
' The TrySetIndex method is called.
' (This method also creates Property1.)
sampleObject(1) = 1
' Getting the Property1 value.
' The TryGetMember method is called.
Console.WriteLine(sampleObject.Property1)
' The following statement produces a run-time exception
' because there is no corresponding property.
' Console.WriteLine(sampleObject(2))
End Sub
输出:
Zero 1