Working with Files

[barmaki]

14.1 Introduction
Up until lesson 13 we are only creating programs that could

accept data at runtime, when a program is terminated, the data

also disappear. Is it possible to save data accepted by a VB

program into a storage device, such as a hard disk or diskette,

or even CDRW? The answer is possible. Is this chapter, we will

learn how to create files by writing them into a storage device

and then retrieve the data by reading the contents of the

files using customized VB programs.

14.2 Creating files
To create a file , use the following command

Open "fileName" For Output As #fileNumber

Each file created must have a file name and a file number for

identification. As for file name, you must also specify the

path where the file will reside.

For example

Open "c:\My ****\sample.txt" For Output As #1

will create a text file by the name of sample.txt in the My

**** folder. The accompany file number is 1. If you wish to

create and save the file in A drive, simply change the path, as

follows"

Open "A:\sample.txt" For Output As #1

If you wish to create a HTML file , simple change the

extension to .html

Open "c:\My ****\sample.html" For Output As # 2

14.2.1 Sample Program : Creating a text file

Private Sub create_****()
Dim intMsg As String
Dim StudentName As String

Open "c:\My ****\sample.txt" For Output As #1
intMsg = MsgBox("File sample.txt opened")
StudentName = InputBox("Enter the student Name")
Print #1, StudentName
intMsg = MsgBox("Writing a" & StudentName & " to sample.txt ")

Close #1

intMsg = MsgBox("File sample.txt closed")
End Sub

* The above program will create a file sample.txt in the My

****' folder and ready to receive input from users. Any

data input by users will be saved in this text file.


14.3 Reading files
To read a file created in section 14.2, you can use the input

# statement. However, we can only read the file according to

the format when it was written. You have to open the file

according to its file number and the variable that hold the

data. We also need to declare the variable using the DIM

command.

14.3.1 Sample Program: Reading file

Private Sub Reading_****()
Dim variable1 As String
Open "c:\My ****\sample.txt" For Input As #1
Input #1, variable1
Text1.Text = variable1
Close #1

End Sub

* This program will open the sample.txt file and display its

contents in the Text1 textbox.

[rwshthn]

you good in that man