本文整理汇总了VB.NET中System.String.IsNullOrEmpty方法的典型用法代码示例。如果您正苦于以下问题：VB.NET String.IsNullOrEmpty方法的具体用法？VB.NET String.IsNullOrEmpty怎么用？VB.NET String.IsNullOrEmpty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.String的用法示例。
在下文中一共展示了String.IsNullOrEmpty方法的3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: Sample
Class Sample
Public Shared Sub Main()
Dim s1 As String = "abcd"
Dim s2 As String = ""
Dim s3 As String = Nothing
Console.WriteLine("String s1 {0}.", Test(s1))
Console.WriteLine("String s2 {0}.", Test(s2))
Console.WriteLine("String s3 {0}.", Test(s3))
End Sub
Public Shared Function Test(s As String) As String
If String.IsNullOrEmpty(s) Then
Return "is null or empty"
Else
Return String.Format("(""{0}"") is neither null nor empty", s)
End If
End Function
End Class输出：
String s1 ("abcd") is neither null nor empty.
String s2 is null or empty.
String s3 is null or empty.
示例2: Main
Module Example
Public Sub Main()
Dim s As String
Console.WriteLine("The value of the string is '{0}'", s)
Try
Console.WriteLine("String length is {0}", s.Length)
Catch e As NullReferenceException
Console.WriteLine(e.Message)
End Try
End Sub
End Module输出：
The value of the string is '' Object reference not set to an instance of an object.
示例3: FileSystem
Option Strict On
Imports System.Collections.ObjectModel
Imports System.IO
Public Module FileSystem
Public Sub Main()
Dim dirPath As String = "c:\\"
If String.IsNullOrEmpty(dirPath) Then Exit Sub
If Not Directory.Exists(dirPath) Then Exit Sub
Dim dirs As ReadOnlyCollection(Of String) = My.Computer.FileSystem.GetDirectories(dirPath)
For Each dir As String In dirs
Dim dirInfo As DirectoryInfo = New DirectoryInfo(dir)
Console.WriteLine("{0} : Created {1}", dirinfo.Name,dirInfo.CreationTime)
Next
End Sub
End Module