Binary Saving Question...

I have a string variable that is set from a textbox text string and I need to save it to a binary file. There are also a bunch of other misc values I have to save to this same file too (Boolean, Single, and String values)

Dim IntroChecked As Boolean
Dim IntroDir As String
Open Filename For Binary Access Write As #1
Put #1, , IntroChecked
Put #1, , IntroDir
Close #1

This doesnt seem to work correctly. The string isn't saved correctly for some odd reason but the IntroChecked value is saved correctly.

I'm thinking that maybe I have to set the IntroDir variable as something other than a string for binary saving. I have no idea.

Please Help.

-Simon Bingier

[Paul282]

what you want to do is use a User defined type

This is from MSDN

Opening a File for Binary Access
To open a file for binary access, use the following syntax for the Open statement:

Open pathname For Binary As filenumber

As you can see, Open for binary access differs from Open for random access in that Len = reclength is not specified. If you include a record length in a binary-access Open statement, it is ignored.

Storing Information in Variable-Length Fields
To best appreciate binary access, consider a hypothetical Employee Records file. This file uses fixed-length records and fields to store information about employees.

Type Person
ID As Integer
MonthlySalary As Currency
LastReviewDate As Long
FirstName As String * 15
LastName As String * 15
Title As String * 15
ReviewComments As String * 150
End Type

Regardless of the actual contents of the fields, every record in that file takes 209 bytes.

You can minimize the use of disk space by using binary access. Because this doesn’t require fixed-length fields, the type declaration can omit the string length parameters.

Type Person
ID As Integer
MonthlySalary As Currency
LastReviewDate As Long
FirstName As String
LastName As String
Title As String
ReviewComments As String
End Type

Public Empl As Person ' Defines a record.

Each employee record in the Employee Records file now stores only the exact number of bytes required because the fields are variable-length. The drawback to binary input/output with variable-length fields is that you can’t access records randomly — you must access records sequentially to learn the length of each record. You can seek directly to a specified byte position in a file, but there is no direct way to know which record is at which byte position if the records are of variable length.

For More Information For additional information on binary file access, see "Open Statement."

[HeSaidJoe]

For files opened in Binary mode, all of the Random rules apply, except:

The Len clause in the Open statement has no effect. Put writes all variables to disk contiguously; that is, with no padding between records.


For any array other than an array in a user-defined type, Put writes only the data. No descriptor is written.


Put writes variable-length strings that are not elements of user-defined types without the 2-byte length descriptor. The number of bytes written equals the number of characters in the string. For example, the following statements write 10 bytes to file number 1:
VarString$ = String$(10," ")
Put #1,,VarString$

[kedaman]

There's nothing wrong with the string actually, there's just no descriptor written for it so you have to make your own, declare a byte or integer variable (or long) depending on the max size of that string, and put the length of the string len(variablename) into the descriptor, and the put the descriptor before putting the string itself, then when you read it with get:

 Dim length as integer
 Get #1,,length
 yourstring=space(length)
 Get #1,,yourstring

you use for instance space to predefine the length of the string, if you pass a nullstring it will return with the rest of the file.