本文整理汇总了VB.NET中System.Collections.ArrayList.ReadOnly方法的典型用法代码示例。如果您正苦于以下问题:VB.NET ArrayList.ReadOnly方法的具体用法?VB.NET ArrayList.ReadOnly怎么用?VB.NET ArrayList.ReadOnly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.Collections.ArrayList
的用法示例。
在下文中一共展示了ArrayList.ReadOnly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: SamplesArrayList
' 导入命名空间
Imports System.Collections
Public Class SamplesArrayList
Public Shared Sub Main()
Dim myStr As [String]
' Creates and initializes a new ArrayList.
Dim myAL As New ArrayList()
myAL.Add("red")
myAL.Add("orange")
myAL.Add("yellow")
' Creates a read-only copy of the ArrayList.
Dim myReadOnlyAL As ArrayList = ArrayList.ReadOnly(myAL)
' Displays whether the ArrayList is read-only or writable.
If myAL.IsReadOnly Then
Console.WriteLine("myAL is read-only.")
Else
Console.WriteLine("myAL is writable.")
End If
If myReadOnlyAL.IsReadOnly Then
Console.WriteLine("myReadOnlyAL is read-only.")
Else
Console.WriteLine("myReadOnlyAL is writable.")
End If
' Displays the contents of both collections.
Console.WriteLine()
Console.WriteLine("Initially,")
Console.WriteLine("The original ArrayList myAL contains:")
For Each myStr In myAL
Console.WriteLine(" {0}", myStr)
Next myStr
Console.WriteLine("The read-only ArrayList myReadOnlyAL contains:")
For Each myStr In myReadOnlyAL
Console.WriteLine(" {0}", myStr)
Next myStr
' Adding an element to a read-only ArrayList throws an exception.
Console.WriteLine()
Console.WriteLine("Trying to add a new element to the read-only ArrayList:")
Try
myReadOnlyAL.Add("green")
Catch myException As Exception
Console.WriteLine(("Exception: " + myException.ToString()))
End Try
' Adding an element to the original ArrayList affects the read-only ArrayList.
myAL.Add("blue")
' Displays the contents of both collections again.
Console.WriteLine()
Console.WriteLine("After adding a new element to the original ArrayList,")
Console.WriteLine("The original ArrayList myAL contains:")
For Each myStr In myAL
Console.WriteLine(" {0}", myStr)
Next myStr
Console.WriteLine("The read-only ArrayList myReadOnlyAL contains:")
For Each myStr In myReadOnlyAL
Console.WriteLine(" {0}", myStr)
Next myStr
End Sub
End Class
输出:
myAL is writable. myReadOnlyAL is read-only. Initially, The original ArrayList myAL contains: red orange yellow The read-only ArrayList myReadOnlyAL contains: red orange yellow Trying to add a new element to the read-only ArrayList: Exception: System.NotSupportedException: Collection is read-only. at System.Collections.ReadOnlyArrayList.Add(Object obj) at SamplesArrayList.Main() After adding a new element to the original ArrayList, The original ArrayList myAL contains: red orange yellow blue The read-only ArrayList myReadOnlyAL contains: red orange yellow blue