Listbox being poplutaed with Access database.

Question

Hi. This is using VB.NET and Access. I am populating a listbox via datasource from an Access Database on FormLoad. I have the listbox set for multi selection. My problem is when I attempt to retrieve the selected items I am getting errors. I have been trying to use the SelectedItems of the ListBox. If I take away the DataSource and load the contents manually, it works fine. I am thinking that using ADO you must retrieve the selected items a different way, but I cannot find anything on the net for a solution. Any help would be greatly appreciated. Thanks

Vijaya Kadiyala · Answer

Hi You can use the below code Private Sub ListBox1_SelectedIndexChanged(ByVal sender As System.Object,_ ByVal e As System.EventArgs) Handles ListBox1.SelectedIndexChanged TextBox1.Text = ListBox1.SelectedItem 'using the selected item property End Sub check out the below link for more information http://www.startvbdotnet.com/controls/listbox.aspx Thanks -- Vj

Vijaya Kadiyala · Answer

Hi You can use the below code Private Sub ListBox1_SelectedIndexChanged(ByVal sender As System.Object,_ ByVal e As System.EventArgs) Handles ListBox1.SelectedIndexChanged TextBox1.Text = ListBox1.SelectedItem 'using the selected item property End Sub check out the below link for more information http://www.startvbdotnet.com/controls/listbox.aspx Thanks -- Vj http://dotnetvj.blogspot.com

greg_isenberg · Answer

Ok, I got it all you have to do is change ListBox2.Items to ListBox2.SelectedItems. Thanks to all that have helped me get this solved.

greg_isenberg · Answer

I have finally figured out how to get all of the items of my listbox with the code below. The final thing that I am wanting to do is just retrieve the selecteditems not all of the items. Can someone show me how to modify the code below to only grab the items that were selected in the listbox? For Each MyItem As DataRowView In ListBox2.Items MessageBox.Show(MyItem.Item("accessories").ToString()) Next

greg_isenberg · Answer

CPUWizard, can you show me an example of how to do this. For some reason I am not getting in my head how to read the rows and how to get the text items that were selected in my listbox. Thanks in Advance.....

david 0 · Answer

When you fill a list box from a datasource you are placing ROWS in the listbox, the listbox is extracting the information from the rows in order to display the proper text. When you retrieve the SelectedItems, you are getting back ROWS. This is the PROPER behaviour! Otherwise you could not eaisly access other associated information from the load. As previouslyy pointyed out you do NOT want to convert the Row to a String() [this yields the default behaviour of returning the type as a string!] but rather need to extract the information out of the row, and then convert that to a string (if necessary).

de_henny · Answer

For as far as i know no DIM statetement is needed. U declare the variable view here with datatype DataRowView. If u use Dim u would get Dim view view = (DataRowView)= (DataRowView)ListBox2.SelectedItems(0); But again i never did anything in VB .NET. only used VB 6.0 ages ago, and currently i am working in C#. and in your case it is MessageBox.Show(view.Row["accessories"].ToString()); The row attribute is a collection of items, so u can specify the index (int), or the name(string); But since i don't know how your dataset is build up i can't fill in the index or columnname for you.

greg_isenberg · Answer

So I would add the following?: DataRowView view = (DataRowView)ListBox2.SelectedItems(0) and MessageBox.Show(view.Row(accessories).ToString()) I tried adding the first line and DataRowView had the swiggly line under it. Do I need to use any Dim statements or something?

de_henny · Answer

Know i see the problem Cause u are using the ListBox.SelectedItems property u retrieve an object calles System.Data.DataRowView If u want the text in the listBox u have the cast the object to a DataRowView object as following : DataRowView view = (DataRowView)lbUsers.SelectedItems[0]; no to retrieve data from the selected row(s). MessageBox.Show(view.Row[columnIndex].toString()); where columnIndex is the column from the dataset that contains the information displayed in the listBox. Finally i see the light :D. lol

greg_isenberg · Answer

It complained big time with Text instead of ToSting() The following error ocurred: An unhandled exception of type 'System.MissingMemberException' occurred in microsoft.visualbasic.dll Additional information: Public member 'Text' on type 'DataRowView' not found.

greg_isenberg · Answer

I will try that. I sent you an email with the Access DB and the VB code. Thanks

de_henny · Answer

by the way have u tried MessageBox.Show(ListBox2.SelectedItems(i).Text) instead of MessageBox.Show(ListBox2.SelectedItems(i).ToString())

de_henny · Answer

well if u are really desperate mail me the code de_henny[AT]hotmail.com it really is something small believe me.

greg_isenberg · Answer

I added the code and I still get the same values as before. My listbox is filling in fine, it is just when I am attempting to get the selecteditems. I have spent hours and hours trying to figure this one out. There must be a step that I am missing but I cannot figure it out. Thanks for the ideas.

de_henny · Answer

sorry didn't see that but before u read data from the listbox make sure it is correctly filled. So start with filling your Dataset. I assume this is no problem. Then set a value member for the control ( if u wish ). Then set the column the listbox should display. Then bind the datasource to the listbox ---> control.ValueMember = dataSet.Tables[0].Columns[0].ColumnName; control.DisplayMember = dataSet.Tables[0].Columns[1].ColumnName; control.DataSource = dataSet.Tables[0] ; and again goodluck ;)

greg_isenberg · Answer

The loop is in the code that I posted earlier. It is actually a For...Next Loop Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Dim i As Integer For i = 0 To ListBox2.SelectedItems.Count - 1 MessageBox.Show(ListBox2.SelectedItems(i).ToString()) Next End Sub End Class All I am attempting to do is grab the selecteditems from the listbox. It works fine when I populate the data into the listbox manually, but as soon as I bind the listbox to the database I get 'System.Data.DataRowView' instead of each item.

de_henny · Answer

Can u post some more code cause i have no idea what u want. I don't what you use the loop for so i can't answer sorry

greg_isenberg · Answer

accessories is field name that I am displaying and also the table name, so I am not sure if it is referencing the table or field in this case. Would I set the DataSource just before my loop or in the loop?

de_henny · Answer

I am programming in C# but converting it to VB is easy I have one more question what is Accesoires ? normally u bind data like this. control.DataSource = dataSet.Tables[0] ; control.ValueMember = dataSet.Tables[0].Columns[0].ColumnName; control.DisplayMember = dataSet.Tables[0].Columns[1].ColumnName;

greg_isenberg · Answer

Do I add DataSet21.Tables(Index) via code, cause I do not see if in the properties window, I only see DataSet21.Accessories and DataSet21 and None. If I need to do this via code can you provide a sample? Thanks a bunch...

de_henny · Answer

try this DataSource: DataSet21.Tables[Index]

greg_isenberg · Answer

The below code will work fine if I just add my items in the items properity manually. Each selected item appears correctly in the MessageBox. Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Dim i As Integer For i = 0 To ListBox2.SelectedItems.Count - 1 MessageBox.Show(ListBox2.SelectedItems(i).ToString()) Next End Sub End Class When I change the ListBox to use the following properties I get 'System.Data.DataRowView' in the MessageBox instead of the actual item: DataSource: DataSet21 DisplayMember: Accessories.Accessories ValueMember: Accessories.ID The ListBox loads the data fine, I just can't seem to access the items appropriately. Please let me know if you need further information.

de_henny · Answer

can u specify the error u are getting or some sample code ?

Listbox being poplutaed with Access database.

Answers (23)