这是一段提供例外的Visual Basic代码,FormatException。Visual Basic文件中的格式异常
假设我的十六进制值变量hexValue
是424E0A78。代码正常工作。当下hexValue
得到的值(比方说)424EA78,出现此异常:
提供的十六进制值是空或者格式不正确。使用以下格式:00000000
是否有解决方案?
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Try
Dim hexValue As String = "424E0A78"
Dim iInputIndex As Integer = 0
Dim iOutputIndex As Integer = 0
Dim bArray(3) As Byte 'creating an array
Dim rnum As Integer
Dim rArray(3) As Byte
Dim rSingle As Single
Dim rSingle1 As Single
Dim rSingle2 As Single
Dim rStr As Integer
Dim rnewArray(3) As Byte ' variables
Dim rnum2, rnum3 As Integer 'variables
Dim rstr2, rstr3 As String
'For iInputIndex = 0 To hexValue.Length - 1 Step 2
For iInputIndex = 0 To hexValue.Length - 1 Step 2
'rnum3 = hexValue.Chars(iInputIndex) * 16
'REjina code starts
rStr = 0
rstr2 = hexValue.Chars(iInputIndex)
If (rstr2 = "A") Then
rstr2 = 10
ElseIf (rstr2 = "B") Then
rstr2 = 11
ElseIf (rstr2 = "C") Then
rstr2 = 12
ElseIf (rstr2 = "D") Then
rstr2 = 13
ElseIf (rstr2 = "E") Then
rstr2 = 14
ElseIf (rstr2 = "F") Then
rstr2 = 15
End If
rStr = Val(rstr2) * 16
'Second rejina conversion
rstr2 = hexValue.Chars(iInputIndex + 1)
If (rstr2 = "A") Then
rstr2 = 10
ElseIf (rstr2 = "B") Then
rstr2 = 11
ElseIf (rstr2 = "C") Then
rstr2 = 12
ElseIf (rstr2 = "D") Then
rstr2 = 13
ElseIf (rstr2 = "E") Then
rstr2 = 14
ElseIf (rstr2 = "F") Then
rstr2 = 15
End If
rStr = rStr + Val(rstr2)
'rstr2 = hexValue.Chars(iInputIndex + 1)
rnewArray(iOutputIndex) = rStr
'rejina code ends
'rArray(iOutputIndex) = Byte.Parse(hexValue.Chars(iInputIndex) & hexValue.Chars(iInputIndex + 1), Globalization.NumberStyles.HexNumber)
'bArray(iOutputIndex) = Convert.ToByte(hexValue.Chars(iInputIndex))
iOutputIndex += 1
Next
'Array.Reverse(rArray)
'rejina code starts
Array.Reverse(rnewArray)
'rejina code ends
'Array.Reverse(bArray)
'rSingle = BitConverter.ToSingle(rArray, 0)
'rejina code starts
rSingle1 = BitConverter.ToSingle(rnewArray, 0)
'rejina code ends
'rSingle2 = BitConverter.ToSingle(bArray, 0)
MessageBox.Show(rSingle1)
'Return BitConverter.ToSingle(rnewArray, 0)
Catch ex As Exception
Throw New FormatException("The supplied hex value is either empty or in an incorrect format. Use the following format: 00000000", ex)
End Try
End Sub
Puhleeze不写这样的代码。使用Integer.TryParse()和NumberStyles.HexNumber参数。 –
我以前只用过Parse。因为它也抛出了同样的例外,我就这样去了。但是在调试了很多之后,这个代码也出现了相同的异常。所以我只想知道VB是否提供了任何方法来克服这种异常。谢谢。 – user46646
你得到的异常类型是什么?你的catch块捕获任何异常,所以很难知道确切的异常。但@HansPassant是正确的,你可以通过使用TryParse(而不是Parse)大大减少这段代码。 –