Visual Basic Code Snippets

  1. Sample Function for Writing to a File
  2. Create a Standard EXE Project. Copy and paste the WriteFile function code block below into the Form's code module. Add an Option Explicit and a Dim Temp line of code at the very top/beginning of the code module, before the WriteFile and ReadFile functions below on this page. Write a Sub routine which responds to a Click Event (see Item #3 below) to call both of these functions, first the WriteFile, then the ReadFile function. Include a line of code in this Sub to display the contents of your testfile.txt in a textbox control. Press F5 to run your program. Click inside your textbox and see your code spring into action!
    Static Function WriteFile()
        'Store in Temp what you want in the file
        Temp = "Sample text"
        'Open file for writing with the Output Statement
        Open "c:\testfile.txt" For Output As #1
        'Write data in file from the Temp variable
        Print #1, Temp
        Close #1  'Close file
    End Function

  3. Sample Function for Reading from a File
  4. Open the Standard EXE Project you created in Item #1. Copy and paste the ReadFile function code block below into the Form after the accompanying WriteFile function code block. NOTE: This code will generate an error if the file does not exist where you direct it to look. Therefore, make sure your code includes a Sub to use the WriteFile function BEFORE it uses the ReadFile function. You will need to add a textbox in which to display your file's text once you've written and read it back.
    Static Function ReadFile()
        'Open file and read contents with the Input Statement
        Open "c:\testfile.txt" For Input As #1 
        Do While Not EOF(1) 'Loop until end of file.
            Input #1, Temp 'Store data in Temp variable
        Loop  'Continue until end of file
        Close #1  'Close file.
    End Function

  5. Sample Sub Routine for a Click Event
  6. Open the Standard EXE Project you created for Item #1. Copy and paste the Sub routine code block below directly into the Form's code module.
    Sub Text1_Click()
        WriteFile 'Call the WriteFile function
        ReadFile 'Call the ReadFile function
        'Print the Temp variable's contents
        'in the textbox when user clicks inside it
        Text1 = Text1 + Temp 
    End Sub

  7. Sample Sub Routine for Moving an Image Across the Screen
  8. Create a Standard EXE Project. Add both a Timer and a Picture Box control to the Form object. Add your image to the Picture Box control using the Properties page. Copy and paste the code below into the Form's code module. Make sure the name of the Picture Box control is the same as what is in the code block below either by using the same name as in the code or by changing the name in the code. Finally, press F5 to run your program.
    Sub Form_Load()
        'Create screen coordinate variables
        Dim DeltaX, DeltaY
        'Initialize variables
        DeltaX = 250
        DeltaY = 250
        'Set Timer Interval
        Timer1.Interval = 250
        'Show the form
    End Sub
    Sub Timer1_Timer()
        'Move picture around and "bounce" off screen
        Picture1.Move Picture1.Left + DeltaX, Picture1.Top + DeltaY
        If Picture1.Left < ScaleLeft Then DeltaX = 250
        If Picture1.Left + Picture1.Width > ScaleWidth + ScaleLeft Then
            DeltaX = -250
        End If
        If Picture1.Top < ScaleTop Then DeltaY = 250
        If Picture1.Top + Picture1.Height > ScaleHeight + ScaleTop Then
            DeltaY = -250
        End If
    End Sub