[RESOLVED] How to compare combobox item to the first 10 digits value in textbox

Hi All,

I want to make a program that will compare the selected items of combo box to the first 10 digits value of text box, user can input up to 24 digits serial no. from the text box. and I will set default value to the items of combo box. example see my code below.
I don't know what to use if else , or select case,
Please help me thank you in advance.

Code:

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Public Class Form1
    Private Sub btnSave_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSave.Click
        ' Case 1
        If cmbModel.SelectedItem.text <> "" Then
            MsgBox("Choose model")
        End If
        ' case 2
        If cmbModel.SelectedItem.text = "PBGS01 (MR SENSOR)" Then
            If txtSerialNo.Text = "11150PP20000%" Then
                MsgBox("Success")
 
            Else
                MsgBox("Model and Serial no not match !")
            End If
        End If
        ' case 3
        If cmbModel.SelectedItem.text = "PBGE01 (ECU BOARD)" Then
            If txtSerialNo.Text = "38700BD20101%" Then
                MsgBox("Success")
 
            Else
                MsgBox("You select wrong Model")
            End If
        End If
        ' case 4
        If cmbModel.SelectedItem.text = "PBGM01 (MCU BOARD)" Then
            If txtSerialNo.Text = "12110PP20000%" Then
                MsgBox("Success")
 
            Else
                MsgBox("You select wrong Model")
            End If
        End If
    End Sub
End Class

---

here is my form look likes.
Attachment 159903

You should start by creating objects that have two properties: one for the value you want to display in the ComboBox and the other for the value you want to compare to the TextBox, e.g.

vb.net Code:

Public Class Model
    Public Property Name As String
    Public Property Code As String
End Class

You can then create a list of instances of that type and bind them to your ComboBox, e.g.

vb.net Code:

Dim models = {New Model With {.Name = "PBGS01 (MR SENSOR)", .Code = "11150PP20000"},
              New Model With {.Name = "PBGE01 (ECU BOARD)", .Code = "38700BD20101"},
              New Model With {.Name = "PBGM01 (MCU BOARD)", .Code = "12110PP20000"}}
 
With cmbModel
    .DisplayMember = "Name"
    .ValueMember = "Code"
    .DataSource = models
End With

You can then compare the selection to the TextBox like this:

vb.net Code:

Dim modelCode = CStr(cmbModel.SelectedValue)
 
If txtSerialNo.Text.StartsWith(modelCode) Then

hi Sir jmcilhinney ,

I got it ! thanks a lot ! ,
how can i mark your answer as my answer ?
or i will just make my thread question as RESOLVED?
I tried to rate your post or add reputation to you but it says "You must spread some Reputation around before giving it to jmcilhinney again."

thanks a lot again !

Quote:

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Originally Posted by BONITO

how can i mark your answer as my answer ?
or i will just make my thread question as RESOLVED?

---

That's all you need to do.

Quote:

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Originally Posted by BONITO

I tried to rate your post or add reputation to you but it says "You must spread some Reputation around before giving it to jmcilhinney again."

---

It's the thought that counts. :)

Quote:

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Originally Posted by jmcilhinney

You should start by creating objects that have two properties: one for the value you want to display in the ComboBox and the other for the value you want to compare to the TextBox, e.g.

vb.net Code:

Public Class Model
Public Property Name As String
Public Property Code As String
End Class

You can then create a list of instances of that type and bind them to your ComboBox, e.g.

vb.net Code:

Dim models = {New Model With {.Name = "PBGS01 (MR SENSOR)", .Code = "11150PP20000"},
New Model With {.Name = "PBGE01 (ECU BOARD)", .Code = "38700BD20101"},
New Model With {.Name = "PBGM01 (MCU BOARD)", .Code = "12110PP20000"}}
 
With cmbModel
.DisplayMember = "Name"
.ValueMember = "Code"
.DataSource = models
End With

You can then compare the selection to the TextBox like this:

vb.net Code:

Dim modelCode = CStr(cmbModel.SelectedValue)
 
If txtSerialNo.Text.StartsWith(modelCode) Then

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Am I right thinking selected value returns an object reference so you need to cast it as type String in order to treat it as a String?

Quote:

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Originally Posted by ident

Am I right thinking selected value returns an object reference so you need to cast it as type String in order to treat it as a String?

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That is correct. The SelectedValue will return the contents of the property/column of the SelectedItem whose name is specified in the ValueMember. Because that property/column contents can be anything, SelectedValue must be type Object. It is indeed up to you to know what type it is and cast as that type.