本文整理汇总了VB.NET中System.NotSupportedException类的典型用法代码示例。如果您正苦于以下问题：VB.NET NotSupportedException类的具体用法？VB.NET NotSupportedException怎么用？VB.NET NotSupportedException使用的例子？那么恭喜您, 这里精选的类代码示例或许可以为您提供帮助。
在下文中一共展示了NotSupportedException类的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: Main
' 导入命名空间
Imports System.IO
Imports System.Text
Imports System.Threading.Tasks
Module Example
Public Sub Main()
Dim enc As Encoding = Encoding.Unicode
Dim value As String = "This is a string to persist."
Dim bytes() As Byte = enc.GetBytes(value)
Dim fs As New FileStream(".\TestFile.dat",
FileMode.Open,
FileAccess.Read)
Dim t As Task = fs.WriteAsync(enc.GetPreamble(), 0, enc.GetPreamble().Length)
Dim t2 As Task = t.ContinueWith(Sub(a) fs.WriteAsync(bytes, 0, bytes.Length))
t2.Wait()
fs.Close()
End Sub
End Module输出：
Unhandled Exception: System.NotSupportedException: Stream does not support writing. at System.IO.Stream.BeginWriteInternal(Byte[] buffer, Int32 offset, Int32 count, AsyncCallback callback, Object state , Boolean serializeAsynchronously) at System.IO.FileStream.BeginWrite(Byte[] array, Int32 offset, Int32 numBytes, AsyncCallback userCallback, Object sta teObject) at System.IO.Stream.<>c.b__53_0(Stream stream, ReadWriteParameters args, AsyncCallback callback, Object state) at System.Threading.Tasks.TaskFactory`1.FromAsyncTrim[TInstance,TArgs](TInstance thisRef, TArgs args, Func`5 beginMet hod, Func`3 endMethod) at System.IO.Stream.BeginEndWriteAsync(Byte[] buffer, Int32 offset, Int32 count) at System.IO.FileStream.WriteAsync(Byte[] buffer, Int32 offset, Int32 count, CancellationToken cancellationToken) at System.IO.Stream.WriteAsync(Byte[] buffer, Int32 offset, Int32 count) at Example.Main()
示例2: Main
' 导入命名空间
Imports System.IO
Imports System.Threading.Tasks
Module Example
Public Sub Main()
Dim name As String = ".\TestFile.dat"
Dim fs As New FileStream(name,
FileMode.Create,
FileAccess.Write)
Console.WriteLine("Filename: {0}, Encoding: {1}",
name, FileUtilities.GetEncodingType(fs))
End Sub
End Module
Public Class FileUtilities
Public Enum EncodingType As Integer
None = 0
Unknown = -1
Utf8 = 1
Utf16 = 2
Utf32 = 3
End Enum
Public Shared Function GetEncodingType(fs As FileStream) As EncodingType
Dim bytes(3) As Byte
Dim t As Task(Of Integer) = fs.ReadAsync(bytes, 0, 4)
t.Wait()
Dim bytesRead As Integer = t.Result
If bytesRead < 2 Then Return EncodingType.None
If bytesRead >= 3 And (bytes(0) = &hEF AndAlso bytes(1) = &hBB AndAlso bytes(2) = &hBF) Then
Return EncodingType.Utf8
End If
If bytesRead = 4 Then
Dim value As UInteger = BitConverter.ToUInt32(bytes, 0)
If value = &h0000FEFF Or value = &hFEFF0000 Then
Return EncodingType.Utf32
End If
End If
Dim value16 As UInt16 = BitConverter.ToUInt16(bytes, 0)
If value16 = &hFEFF Or value16 = &hFFFE Then
Return EncodingType.Utf16
End If
Return EncodingType.Unknown
End Function
End Class输出：
Unhandled Exception: System.NotSupportedException: Stream does not support reading. at System.IO.Stream.BeginReadInternal(Byte[] buffer, Int32 offset, Int32 count, AsyncCallback callback, Object state, Boolean serializeAsynchronously) at System.IO.FileStream.BeginRead(Byte[] array, Int32 offset, Int32 numBytes, AsyncCallback userCallback, Object stat eObject) at System.IO.Stream.<>c.b__43_0(Stream stream, ReadWriteParameters args, AsyncCallback callback, O bject state) at System.Threading.Tasks.TaskFactory`1.FromAsyncTrim[TInstance,TArgs](TInstance thisRef, TArgs args, Func`5 beginMet hod, Func`3 endMethod) at System.IO.Stream.BeginEndReadAsync(Byte[] buffer, Int32 offset, Int32 count) at System.IO.FileStream.ReadAsync(Byte[] buffer, Int32 offset, Int32 count, CancellationToken cancellationToken) at System.IO.Stream.ReadAsync(Byte[] buffer, Int32 offset, Int32 count) at FileUtilities.GetEncodingType(FileStream fs) at Example.Main()
示例3: GetEncodingType
Public Class FileUtilities
Public Enum EncodingType As Integer
None = 0
Unknown = -1
Utf8 = 1
Utf16 = 2
Utf32 = 3
End Enum
Public Shared Function GetEncodingType(fs As FileStream) As EncodingType
If Not fs.CanRead Then
Return EncodingType.Unknown
Dim bytes(3) As Byte
Dim t As Task(Of Integer) = fs.ReadAsync(bytes, 0, 4)
t.Wait()
Dim bytesRead As Integer = t.Result
If bytesRead < 2 Then Return EncodingType.None
If bytesRead >= 3 And (bytes(0) = &hEF AndAlso bytes(1) = &hBB AndAlso bytes(2) = &hBF) Then
Return EncodingType.Utf8
End If
If bytesRead = 4 Then
Dim value As UInteger = BitConverter.ToUInt32(bytes, 0)
If value = &h0000FEFF Or value = &hFEFF0000 Then
Return EncodingType.Utf32
End If
End If
Dim value16 As UInt16 = BitConverter.ToUInt16(bytes, 0)
If value16 = &hFEFF Or value16 = &hFFFE Then
Return EncodingType.Utf16
End If
Return EncodingType.Unknown
End Function
End Class输出：
Filename: .\TestFile.dat, Encoding: Unknown