Programming Forums > Application Development > Visual Basic .NET

IceNeo · Nov 9th, 2005, 10:40 PM

What I am trying to do is a very simple encrypt/decrypt program. I must point out now that I am very new at this and this is my first working program.

I load a file into a text box and have the content of the textbox in a variable. I need to then assign the first 20 characters into an array, change the characters, then read the array backwards.

This is what I came up with:

(Toggle Plain Text)

FileOpen(1, OpenFileDialog1.FileName, OpenMode.Input)
        Do While Not EOF(1)
            Dim InputArry(19) As String
            VarCount = 0
            Do While Not VarCount < 19 And Not EOF(1)
                InputArry(VarCount) = InputString(textFile, 1)
                ThisChar = Asc(InputArry(VarCount))
                Select Case ThisChar
                    Case 90
                        TempText = 65
                    Case 65 To 98
                        TempText += 1
                    Case 122
                        TempText = 97
                    Case 97 To 121
                        TempText += 1
                    Case Else
                        TempText = TempText
                End Select
                InputArry(VarCount) = Chr(TempText)
                VarCount = VarCount + 1
            Loop
            For AVar = VarCount To 0 Step -1
                StrO = StrO & InputArry(AVar)
            Next
        Loop
        FileClose(1)
        txtBox.Clear()
        txtBox.Text = StrO

Any suggestions? What am I doing wrong?

Rory · Nov 10th, 2005, 12:13 PM

Well your code looks like it (could) work, could you post the exact error message (I expect its an array bounds error). However, this is a distinctly VB6-ish approach: remember strings are arrays of characters, your function creates, marshals, and destroys loads of unecessary objects. Put Option Explicit and Strict on for starters to see where, and leave them on. The .NET way of doing this would be creating a stream processor, and using a stack for the reversal. However if this is your first program, I'd suggest mastering something like ROT13 first.

Nov 9th, 2005, 10:40 PM	#1
IceNeo Newbie Join Date: Nov 2005 Posts: 1 Rep Power: 0	Assigning first character of variable into an array What I am trying to do is a very simple encrypt/decrypt program. I must point out now that I am very new at this and this is my first working program. I load a file into a text box and have the content of the textbox in a variable. I need to then assign the first 20 characters into an array, change the characters, then read the array backwards. This is what I came up with: (Toggle Plain Text) FileOpen(1, OpenFileDialog1.FileName, OpenMode.Input) Do While Not EOF(1) Dim InputArry(19) As String VarCount = 0 Do While Not VarCount < 19 And Not EOF(1) InputArry(VarCount) = InputString(textFile, 1) ThisChar = Asc(InputArry(VarCount)) Select Case ThisChar Case 90 TempText = 65 Case 65 To 98 TempText += 1 Case 122 TempText = 97 Case 97 To 121 TempText += 1 Case Else TempText = TempText End Select InputArry(VarCount) = Chr(TempText) VarCount = VarCount + 1 Loop For AVar = VarCount To 0 Step -1 StrO = StrO & InputArry(AVar) Next Loop FileClose(1) txtBox.Clear() txtBox.Text = StrO FileOpen(1, OpenFileDialog1.FileName, OpenMode.Input) Do While Not EOF(1) Dim InputArry(19) As String VarCount = 0 Do While Not VarCount < 19 And Not EOF(1) InputArry(VarCount) = InputString(textFile, 1) ThisChar = Asc(InputArry(VarCount)) Select Case ThisChar Case 90 TempText = 65 Case 65 To 98 TempText += 1 Case 122 TempText = 97 Case 97 To 121 TempText += 1 Case Else TempText = TempText End Select InputArry(VarCount) = Chr(TempText) VarCount = VarCount + 1 Loop For AVar = VarCount To 0 Step -1 StrO = StrO & InputArry(AVar) Next Loop FileClose(1) txtBox.Clear() txtBox.Text = StrO Any suggestions? What am I doing wrong?

Thread Tools
Show Printable Version Email this Page
Display Modes
Switch to Linear Mode Hybrid Mode Switch to Threaded Mode

Nov 10th, 2005, 12:13 PM	#2
Rory Expert Programmer Join Date: Jan 2005 Location: London Posts: 542 Rep Power: 4	Well your code looks like it (could) work, could you post the exact error message (I expect its an array bounds error). However, this is a distinctly VB6-ish approach: remember strings are arrays of characters, your function creates, marshals, and destroys loads of unecessary objects. Put Option Explicit and Strict on for starters to see where, and leave them on. The .NET way of doing this would be creating a stream processor, and using a stack for the reversal. However if this is your first program, I'd suggest mastering something like ROT13 first.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)

Programming Forums > Application Development > Visual Basic .NET

Assigning first character of variable into an array