How can i multi select items in listbox and pass values to a textbox

[smile4kenny]

Please I need help.

I have a listbox that has multiselect property.

I am having problems writing code to help me multi select items in the listbox and on a click event, items will display on a textbox that has a multi line property.

Thanks in advance

[jmcilhinney]

Um, you posted this exact same question in the VB6 forum a couple of hours ago. Firstly, please don't double post. If you find that you have posted in the wrong forum then please ask the moderators to move the thread. VB6 and VB.NET are two different languages so if people start posting to both threads then at least one group is going to be wasting their time. That's not the way to make friends.

So, which language are you using? Is it VB6 or VB.NET? Note that VB 2005 and later are VB.NET. We can then get the mods to delete the irrelevant thread and people can try to help you out, safe in the knowledge that there answers will be relevant and their time not wasted.

[smile4kenny]

sorry about that

VB.NET

[jmcilhinney]

Assuming that the items in the ListBox are Strings in the first place, the simplest option is:

myTextBox.Lines = myListBox.SelectedItems.Cast(Of String)().ToArray()

That creates a String array from the selected items and displays it one element per line in the TextBox.

[smile4kenny]

I tried your code and this error came up

Unable to cast object of type 'System.Data.DataRowView' to type 'System.String

Please help

[.paul.]

try this:

Private Sub ListBox1_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ListBox1.SelectedIndexChanged
    If ListBox1.DisplayMember = "" Then Return
    TextBox1.Lines = ListBox1.SelectedItems.Cast(Of DataRowView).Select(Function(drv) drv.Item(ListBox1.DisplayMember).ToString).ToArray()
End Sub

[jmcilhinney]

I tried your code and this error came up

Unable to cast object of type 'System.Data.DataRowView' to type 'System.String

Please help

Given that I said:

Assuming that the items in the ListBox are Strings in the first place

that's not a surprise.

try this:

Private Sub ListBox1_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ListBox1.SelectedIndexChanged
    If ListBox1.DisplayMember = "" Then Return
    TextBox1.Lines = ListBox1.SelectedItems.Cast(Of DataRowView).Select(Function(drv) drv.Item(ListBox1.DisplayMember).ToString).ToArray()
End Sub

There's a better approach that will work in all cases:

TextBox1.Lines = ListBox1.SelectedItems.
                          Cast(Of Object).
                          Select(Function(o) ListBox1.GetItemText(o)).
                          ToArray()

[smile4kenny]

Okay thanks bro...

I modified your code and it worked this way

For Each objDataRowView As DataRowView In Me.ClassTitleListBox.SelectedItem
Me.TextBox1.Text &= (objDataRowView("ClassTitle").ToString() & ",")

Next

But, If I wanna save the output to an array instead of displaying on a textbox, do you know how I can do it?

Thanks in advance

[Shaggy Hiker]

Rather than an array, use a List(of String). Your inner line changes from:

Me.TextBox1.Text &= (objDataRowView("ClassTitle").ToString() & ",")

into

whateverMyListIsCalled.Add(objDataRowView("ClassTitle").ToString)

You just have to declare a New List(of String) with whatever name is better than what I used as a name.

[smile4kenny]

Hi Shaggy,

what if I am using this code, how can I store the output as a list of string
If CourseTitleListBox.DisplayMember = "" Then Return
TextBox1.Lines = CourseTitleListBox.SelectedItems.Cast(Of DataRowView).Select(Function(drv) drv.Item(CourseTitleListBox.DisplayMember).ToString).ToArray()

[smile4kenny]

Please someone help!

I need to store the output in an array or string with comma seperating each item, because I will run an sql query that will search each of the stored item with a where statement.

[Shaggy Hiker]

The code you just showed already returns an array of string. That's what the .ToArray is. Alternatively, you could still use a list by changing that to .ToList, but since you are using that code, I see no reason to do that. TextBox1.Lines is an array of string. You could also have your own array of strings:

Dim MyArray() As String

and assign to that rather than assigning to TextBox1.Lines.

[smile4kenny]

Thanks Shaggy I really do appreciate.

Instead of using an array,
do you know how I can store this as a string with comma seperating each items

[smile4kenny]

When I assign to Dim MyArray() As String

The output is system.String[]

[.paul.]

dim outPut as string = string.join(",", CourseTitleListBox.SelectedItems.Cast(Of DataRowView).Select(Function(drv) drv.Item(CourseTitleListBox.DisplayMember).ToString).ToArray())

[smile4kenny]

Thanks paul!