i have issues here to webrequest login

Hi there,

Before providing a fix, I need to clarify what type of application you are building, as there is a conflict in your question.

1. If this is a Windows Forms (Desktop) Application: I see you are using Form2.Show() and Me.Hide(), which suggests this is a desktop program running on the user's computer. If so, your code runs on the client, and MessageBox will work fine. However, you are mixing up your URL construction. You cannot create a separate WebRequest for the port; the port must be part of the URL string (e.g., http://hostname:8000).

2. If this is an ASP.NET (Web) Application: You mentioned "login on the browser." If this code is running in a web application (code-behind), MessageBox will not work.

The Issue: Web code runs on the server, not the client's machine. If you invoke a MessageBox, it tries to open a window on the server rack in the data center, which the user cannot see.

The Login Flow: In a web environment, you don't "Show" forms. Instead, successful logins usually generate an Authentication Cookie. The server sends this cookie to the browser, and the browser sends it back on every subsequent request to prove who the user is.

Next Steps: Could you confirm if this is a Desktop Application trying to connect to a website, or a Web Application running on a server? The solution is very different for each.

1. Send a web request (POST) with login credentials
2. Check the server response
3. If login succeeds → Show Form2
4. If login fails → Show Frm_Error with the server’s error message

I’ll show you the VB.NET WinForms version because your description matches that style.

✅ VB.NET – Login Request + Load Form2 + Error Handling

Login Form Code (Frm_Login.vb)

Imports System.Net

Imports System.Text

Imports System.IO

Imports Newtonsoft.Json

Public Class Frm_Login

Private Async Sub btnLogin_Click(sender As Object, e As EventArgs) Handles btnLogin.Click

    Dim url As String = "https://yourserver.com/api/login"

    Dim credentials = New With {

        .username = txtUsername.Text.Trim(),

        .password = txtPassword.Text.Trim()

    }

    Dim jsonData As String = JsonConvert.SerializeObject(credentials)

    Dim dataBytes As Byte() = Encoding.UTF8.GetBytes(jsonData)

    Try

        Dim request = CType(WebRequest.Create(url), HttpWebRequest)

        request.Method = "POST"

        request.ContentType = "application/json"

        request.ContentLength = dataBytes.Length

        Using reqStream = Await request.GetRequestStreamAsync()

            reqStream.Write(dataBytes, 0, dataBytes.Length)

        End Using

        Dim response = CType(Await request.GetResponseAsync(), HttpWebResponse)

        Using reader As New StreamReader(response.GetResponseStream())

            Dim serverReply As String = reader.ReadToEnd()

            ' If login successful, your server MUST return something like:

            ' {"status":"success"} or include a token

            If serverReply.ToLower().Contains("success") Then

                Me.Hide()

                Frm2.Show()

            Else

                Frm_Error.lblMessage.Text = "Login failed: " & serverReply

                Frm_Error.ShowDialog()

            End If

        End Using

    Catch ex As WebException

        ' Server returned an error (bad credentials, 500, etc.)

        Dim errText As String = "Unknown error."

        If ex.Response IsNot Nothing Then

            Using reader As New StreamReader(ex.Response.GetResponseStream())

                errText = reader.ReadToEnd()

            End Using

        End If

        Frm_Error.lblMessage.Text = "Login error: " & errText

        Frm_Error.ShowDialog()

    Catch ex As Exception

        Frm_Error.lblMessage.Text = "Exception: " & ex.Message

        Frm_Error.ShowDialog()

    End Try

End Sub

End Class

✅ Form2 (Frm2.vb)

Opens only when login is successful:

Public Class Frm2

' Your Form2 logic here

End Class

✅ Error Form (Frm_Error.vb)

Have a label to show the server error:

Public Class Frm_Error

' Label name should be lblMessage

End Class

✅ How It Works

Sends a POST with username/password

Reads server response

If “success” found → loads Frm2

If anything else → opens Frm_Error with message

Web exceptions (wrong URL, 401/403, server down, etc.) also show Frm_Error