I'm trying to save and then load a multi-dimensional VBA array to/from disk. According to the MSDN website, the number of dimensions are saved as a descriptor in the file, but I can't figure out how to access/load them. The example below works, but only because I have hard coded the array dimensions. The commented out line works in a dynamic sense, but the array's dimensions are lost in the process.
Here's some sample code:
Sub WriteArray() Dim file_name As String Dim file_length As Long Dim fnum As Integer Dim values() As Boolean ReDim values(1 To 5, 1 To 10, 1 To 20) Dim i As Integer 'Populate the simple array For i = 1 To 20 values(1, 1, i) = True Next ' Delete existing file (if any). file_name = "array.to.file.vba.bin" On Error Resume Next Kill file_name On Error GoTo 0 ' Save the file. fnum = FreeFile Open file_name For Binary As #fnum Put #fnum, 1, values Close fnum End Sub Sub ReadArray() Dim file_name As String Dim file_length As Long Dim fnum As Integer Dim newArray() As Boolean file_name = "array.to.file.vba.bin" 'txtFile.Text" fnum = FreeFile file_length = FileLen(file_name) 'ReDim newArray(1 To file_length) 'This loads the data, but not with the right dimensions. ReDim newArray(1 To 5, 1 To 10, 1 To 20) 'This works but with dimensions hard coded. 'How to re-dim here using the dimensions saved in the file? Open file_name For Binary As #fnum Get #fnum, 1, newArray Close fnum End Sub
I need to give credit to the VB Helper website because the example above is based on one they posted here.
To be honest I didn't know this VBA technique which allows to write array into text file. Or maybe I forgot it. :) Therefore I dived into it.
1st. Writing to the file.
I have some problems with Boolean type of your array. It's not working but it's working with Variant type. And I changed open mode from Binary to Random. Moreover, I used Len parameter for Open Statement with value according to this MSDN information.
This is the first sub improved:
Sub WriteArray() Dim file_name As String Dim file_length As Long Dim fnum As Integer Dim values() As Variant ReDim values(1 To 5, 1 To 10, 1 To 20) Dim i As Integer 'Populate the simple array For i = 1 To 20 values(1, 1, i) = True Next ' Delete existing file (if any). file_name = "array.to.file.vba.bin" On Error Resume Next Kill file_name On Error GoTo 0 ' Save the file. fnum = FreeFile '<<<<<<< this is new >>>>>>> Dim arrLen As Long arrLen = (2 + 3 * 8) + (5 * 10 * 20 * 3) '<<<<<<< this is changed >>>>>>> Open file_name For Random As #fnum Len = arrLen Put #fnum, 1, values Close fnum End Sub
2nd. Reading from file
Our array will be Variant type dynamic. I changed file open type to Random from Binary and used Len parameter with the max possible value according to this MSDN information.
This is the second sub improved:
Sub ReadArray() Dim file_name As String Dim fnum As Integer Dim newArray() As Variant file_name = "array.to.file.vba.bin" 'txtFile.Text" fnum = FreeFile '<<<<<<< this is new >>>>>>> Dim lenAAA lenAAA = 32767 '>>> MAX possible value '<<<<<<< this is changed >>>>>>> Open file_name For Random As #fnum Len = lenAAA Get #fnum, 1, newArray Close fnum End Sub
Screen shot of variables value.
