Member Avatar for nevets04

How can i set Textbox1.text equal to the conents of file.txt?

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  • Latest Post Latest Post by Damon88

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The short answer from and is correct: read the file and assign its contents to TextBox1.Text. For ASP.NET WebForms there are a few practical details that often get missed: map relative paths to a physical path, avoid overwriting the box on postbacks, handle encoding and errors, and ensure the web app account has read permission. 's My.Computer approach is fine for desktop apps, but prefer System.IO in server code.

Example (ASP.NET VB.NET, safe pattern):

Protected Sub Page_Load(sender As Object, e As EventArgs) Handles Me.Load
    If Not IsPostBack Then
        Try
            Dim filePath As String = Server.MapPath("~/App_Data/file.txt")
            Dim content As String = System.IO.File.ReadAllText(filePath, System.Text.Encoding.UTF8)
            TextBox1.Text = content
        Catch ex As Exception
            ' log exception and show safe message
            TextBox1.Text = "Unable to load file."
        End Try
    End If
End Sub

Notes and troubleshooting:

  • Put files in App_Data (not served directly) and use Server.MapPath to resolve ~ paths. See HttpServerUtility.MapPath docs for details.
  • For very large files use File.ReadLines or a StreamReader and append to a StringBuilder to avoid high memory use.
  • Ensure the IIS app pool identity has read access to the file location; lack of permission causes UnauthorizedAccessException.
  • Use a multiline TextBox (TextMode="MultiLine") to preserve line breaks. If the file contains HTML that must be shown as text, apply encoding before rendering.
  • Never accept raw file paths from users without validation (path traversal risk).

Reference: System.IO.File.ReadAllText, HttpServerUtility.MapPath.

Recommended Answers

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Member Avatar for SecurExpert

You need to read the file first n then store the content in the textbox1.text.hope you are familia with file operations.

Member Avatar for kvprajapati

Use methods of System.IO.File class.

If System.IO.File.ReadAllText("file.txt") = TextBox1.Text Then
  'Put your code
End If
Member Avatar for Damon88

How can i set Textbox1.text equal to the conents of file.txt?

'to read text from a plain text file we have 
My.Computer.filesystem.ReadAllText

'to read a binary file we have 

my.computer.filesystem.ReadAllBytes


'Answer to your question , although your questions have multiple
'answers

textbox1.text = My.Computer.Filesystem.ReadAllText("Absolute File Path")
'like C:\testfile.txt

'to save the contents of textbox to a file
my.computer.filesystem.WriteAllText("File Path",textbox1.text,false)
'last parameter false for dont append
Edited by Damon88 because: n/a
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