VB.NET InvalidCastException類代碼示例

本文整理匯總了VB.NET中System.InvalidCastException類的典型用法代碼示例。如果您正苦於以下問題：VB.NET InvalidCastException類的具體用法？VB.NET InvalidCastException怎麽用？VB.NET InvalidCastException使用的例子？那麽, 這裏精選的類代碼示例或許可以為您提供幫助。

在下文中一共展示了InvalidCastException類的3個代碼示例，這些例子默認根據受歡迎程度排序。您可以為喜歡或者感覺有用的代碼點讚，您的評價將有助於係統推薦出更棒的VB.NET代碼示例。

示例1: Example

Module Example
   Public Sub Main()
      Dim flag As Boolean = True
      Try
         Dim conv As IConvertible = flag
         Dim ch As Char = conv.ToChar(Nothing)
         Console.WriteLine("Conversion succeeded.")
      Catch e As InvalidCastException   
         Console.WriteLine("Cannot convert a Boolean to a Char.")
      End Try
      
      Try
         Dim ch As Char = Convert.ToChar(flag)
         Console.WriteLine("Conversion succeeded.")
      Catch e As InvalidCastException   
         Console.WriteLine("Cannot convert a Boolean to a Char.")
      End Try
   End Sub
End Module

開發者ID:VB.NET開發者，項目名稱:System，代碼行數:19，代碼來源:InvalidCastException

輸出：

Cannot convert a Boolean to a Char.
Cannot convert a Boolean to a Char.

示例2: Person

Public Class Person
   Dim _name As String
   
   Public Property Name As String
      Get
         Return _name
      End Get
      Set
         _name = value
      End Set
   End Property
End Class

Public Class PersonWithID : Inherits Person
   Dim _id As String
   
   Public Property Id As String
      Get
         Return _id
      End Get
      Set
         _id = value
      End Set
   End Property
End Class

Module Example
   Public Sub Main()
      Dim p As New Person()
      p.Name = "John"
      Try
         Dim pid As PersonWithId = CType(p, PersonWithId)
         Console.WriteLine("Conversion succeeded.")
      Catch e As InvalidCastException
         Console.WriteLine("Conversion failed.")
      End Try 
      
      Dim pid1 As New PersonWithId()
      pid1.Name = "John"
      pid1.Id = "246"
      Dim p1 As Person = pid1
      
      Try   
         Dim pid1a As PersonWithId = CType(p1, PersonWithId)
         Console.WriteLine("Conversion succeeded.")
      Catch e As InvalidCastException
         Console.WriteLine("Conversion failed.")
      End Try 
      
      Dim p2 As Person = Nothing
      Try   
         Dim pid2 As PersonWithId = CType(p2, PersonWithId)
         Console.WriteLine("Conversion succeeded.")
      Catch e As InvalidCastException
         Console.WriteLine("Conversion failed.")
      End Try 
   End Sub
End Module

開發者ID:VB.NET開發者，項目名稱:System，代碼行數:58，代碼來源:InvalidCastException

輸出：

Conversion failed.
Conversion succeeded.
Conversion succeeded.

示例3: Main

' 導入命名空間
Imports System.Globalization

Module Example
   Public Sub Main()
      Dim culture As CultureInfo = CultureInfo.InvariantCulture
      Dim provider As IFormatProvider = culture
      
      Dim dt As DateTimeFormatInfo = CType(provider, DateTimeFormatInfo)
   End Sub
End Module

開發者ID:VB.NET開發者，項目名稱:System，代碼行數:11，代碼來源:InvalidCastException

輸出：

Unhandled Exception: System.InvalidCastException: 
Unable to cast object of type 'System.Globalization.CultureInfo' to 
type 'System.Globalization.DateTimeFormatInfo'.
at Example.Main()

注：本文中的System.InvalidCastException類示例由純淨天空整理自Github/MSDocs等開源代碼及文檔管理平台，相關代碼片段篩選自各路編程大神貢獻的開源項目，源碼版權歸原作者所有，傳播和使用請參考對應項目的License；未經允許，請勿轉載。