本文整理匯總了VB.NET中System.Collections.Generic.Dictionary<TKey,TValue>.Item屬性的典型用法代碼示例。如果您正苦於以下問題：VB.NET Dictionary<TKey,TValue>.Item屬性的具體用法？VB.NET Dictionary<TKey,TValue>.Item怎麽用？VB.NET Dictionary<TKey,TValue>.Item使用的例子？那麽, 這裏精選的屬性代碼示例或許可以為您提供幫助。您也可以進一步了解該屬性所在類System.Collections.Generic.Dictionary<TKey,TValue>的用法示例。
在下文中一共展示了Dictionary<TKey,TValue>.Item屬性的4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: Dictionary
' Create a new dictionary of strings, with string keys.
'
Dim openWith As New Dictionary(Of String, String)
' Add some elements to the dictionary. There are no
' duplicate keys, but some of the values are duplicates.
openWith.Add("txt", "notepad.exe")
openWith.Add("bmp", "paint.exe")
openWith.Add("dib", "paint.exe")
openWith.Add("rtf", "wordpad.exe")
' The Add method throws an exception if the new key is
' already in the dictionary.
Try
openWith.Add("txt", "winword.exe")
Catch
Console.WriteLine("An element with Key = ""txt"" already exists.")
End Try示例2: openWith
' The Item property is the default property, so you
' can omit its name when accessing elements.
Console.WriteLine("For key = ""rtf"", value = {0}.", _
openWith("rtf"))
' The default Item property can be used to change the value
' associated with a key.
openWith("rtf") = "winword.exe"
Console.WriteLine("For key = ""rtf"", value = {0}.", _
openWith("rtf"))
' If a key does not exist, setting the default Item property
' for that key adds a new key/value pair.
openWith("doc") = "winword.exe"示例3: openWith
' The default Item property throws an exception if the requested
' key is not in the dictionary.
Try
Console.WriteLine("For key = ""tif"", value = {0}.", _
openWith("tif"))
Catch
Console.WriteLine("Key = ""tif"" is not found.")
End Try示例4:
' When a program often has to try keys that turn out not to
' be in the dictionary, TryGetValue can be a more efficient
' way to retrieve values.
Dim value As String = ""
If openWith.TryGetValue("tif", value) Then
Console.WriteLine("For key = ""tif"", value = {0}.", value)
Else
Console.WriteLine("Key = ""tif"" is not found.")
End If