Question

Hello Dear Sir, I am using visual Basic 2010 Express, I want to make a little application for my own works. I have set 8 combo boxes in one columns and 6 combos in one row. and one save button for saving the data of all combos and to load. but i still could not find the source code to save the data value of combos. please kindly help me. by sending me source code for saving and loading data value of all combo boxes.

Answer 1

Answer on Question# 38917 – Saving combobox settings - Programming, Visual Basic

To keep combobox states, the application need to store its settings in outer storage: plain text file, XML, CSV or other file formats, database or windows registry.

Below is the example for most simple case with plain text file. The form has two comboboxes and "Save" and "Load" buttons. The applications writes and reads the selected index for each combobox in the file.

Imports System.IO
Public Class Form1
    'populating comboboxes with test values
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        ComboBox1.Items.Add("test1")
        ComboBox1.Items.Add("test2")
        ComboBox1.Items.Add("test3")
        ComboBox2.Items.Add("test1")
        ComboBox2.Items.Add("test2")
        ComboBox2.Items.Add("test3")
    End Sub
    'Load settings button
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        'Loading settings file into streamreader
        Dim reader As New StreamReader(Application.StartupPath & "\settings.txt")
        Dim line As String = ""
        'reading file line by line
        Dim settings() As String
        While reader.Peek() > -1
            line = reader.ReadLine
            'splitting each line into 2-dimensional array, using "=" as separator
            settings = line.Split("="c)
            'selecting corresponding comboboxes
            Select Case settings(0)
                Case "Box1"
                    ComboBox1.SelectedIndex = CInt(settings(1))
                Case "Box2"
                    ComboBox2.SelectedIndex = CInt(settings(1))
            End Select
        End While
        reader.Close()
    End Sub
    'Save settings button
    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        'opening streamwriter object, to write into the settings file
        Dim writer As New StreamWriter(Application.StartupPath & "\settings.txt")
        'writing selected indexes into the settings file
        writer.WriteLine("Box1=" & ComboBox1.SelectedIndex.ToString())
        writer.WriteLine("Box2=" & ComboBox2.SelectedIndex.ToString())
        writer.Close()
    End Sub
End Class

The approach is similar for storing combobox text values. Save routine should write lines with corresponding box values:

For i = 0 To ComboBox1.Items.Count - 1
    writer.WriteLine("box1Value=" & ComboBox1.Items.Item(i).ToString())
Next

The reading routine should populate comboboxes with values retrieved with settings file:

While reader.Peek() > -1
    line = reader.ReadLine
    'splitting each line into 2-dimensional array, using "=" as separator
    settings = line.Split("="c)
    'selecting corresponding comboboxes
    Select Case settings(0)
        Case "box1Value"
            ComboBox1.Items.Add(settings(1))
    End Select
End While