Binding an Array to a Combo Box

[Jim Shaffer]

Perhaps I have the wrong construct, or misunderstand arrays in vb (2003)....
I've loaded a two-dimensional array (168 by 28) into memory as AcctArray.
{Dim AcctArray (500,28) as string...}

The AcctArray is loaded from a Quickbooks table, so there's no intrinsic
dataset to assign as datasource....

I want to have a combo table (or list table or whatever), currently named
cbAccounts, that can scroll through and maybe select items in the array. I
don't want to display all elements, just columns 1,2,6, and 13...

How do I construct this? A combo box is supposed to have as its datasource
an "array", but I can't seem to accomplish it. I can do

cbAccounts.Items.Add(AcctArray(j,1) & " " & AcctArray(j,2) & " " &
Acctarray(j,6) & " " & AcctArray(j,13))

but that doesn't accomplish my objectives...


Can someone give me a nudge?

Thanx in advance

 

[Guest]

You're on the right track. The datasource must implement IList.

As you concatenate the items you want to display from the array, use a loop
to add each resulting string to an ArrayList.

Then set the Combobox datasource to the arraylist.

When you select an item from the dropdown, the selectedindex property will
correspond to the second dimension index of your original array, assuming you
use each item in the original array.

You might also look into the displaymember and valuemember properties of the
ComboBox. If you wanted to use them you might use a Datatable instead of an
ArrayList. You would then assign those two properties to the appropriate
fields. This approach allows you to use the SelectedValue property of the
ComboBox.

www.charlesfarriersoftware.com

 

[Cor Ligthert]

Jim,

That usefull however terrible combobox have 2 methods for binding and one
method to add items.

It is the adding of items
the binding from the textboxpart (what is not your option)
the binding using the datasource to an Ilist array

You go now for adding items from the array to the arraylist from the
combobox.

That is not directly binding. What you can do is creating an array with
objects. Those you can bind using the datasource to the combobox. You can
get the information by casting it to a datarowview.

Because this I find more work than needed, I make in this kind of situations
just a datatable and bind it using the defaultview to that combobox. That
cost at least 10 times less time to do.

Just my thought,

Cor

 

[Jay B. Harlow [MVP - Outlook]]

Jim,
In addition to the other comments.

| How do I construct this? A combo box is supposed to have as its datasource
| an "array", but I can't seem to accomplish it. I can do
I've bound to single dimension arrays without any problems, I have not tried
binding to either 2 dimensional arrays or jagged/ragged arrays before.

I will see if I can find any information on binding to a 2 dimensional
array.

In the meantime, you could always convert the array into a DataTable.
Something like:

Const rows As Integer = 0
Const columns As Integer = 1

Dim table As DataTable

For rowIndex As Integer = acctArray.GetLowerBound(rows) To
acctArray.GetUpperBound(rows)
Dim row As DataRow = table.NewRow
For columnIndex As Integer = acctArray.GetLowerBound(columns) To
acctArray.GetUpperBound(columns)
row(columnIndex) = acctArray(rowindex, columnindex)
Next
table.Rows.Add(row)
Next

Which assumes that "table" has the same number of columns as your array.

Hope this helps
Jay



| Perhaps I have the wrong construct, or misunderstand arrays in vb
(2003)....
| I've loaded a two-dimensional array (168 by 28) into memory as AcctArray.
| {Dim AcctArray (500,28) as string...}
|
| The AcctArray is loaded from a Quickbooks table, so there's no intrinsic
| dataset to assign as datasource....
|
| I want to have a combo table (or list table or whatever), currently named
| cbAccounts, that can scroll through and maybe select items in the array. I
| don't want to display all elements, just columns 1,2,6, and 13...
|
| How do I construct this? A combo box is supposed to have as its datasource
| an "array", but I can't seem to accomplish it. I can do
|
| cbAccounts.Items.Add(AcctArray(j,1) & " " & AcctArray(j,2) & " " &
| Acctarray(j,6) & " " & AcctArray(j,13))
|
| but that doesn't accomplish my objectives...
|
|
| Can someone give me a nudge?
|
| Thanx in advance
|
| --
| Jim Shaffer
|
|

 

[Jay B. Harlow [MVP - Outlook]]

Jim,
I was playing with this a little.

Is this Windows Forms or Web Forms?

In Windows Forms, you can bind a list control (ListBox, ComboBox, DataGrid)
to a one-dimensional array, however you cannot bind to a two-dimensional
array. Which is understandable, as the list controls use IList to support
binding. Array implements IList. If you use IList from a one-dimensional
array you get the list of numbers. If you use IList from a two-dimensional
array you get a single list of numbers & not the rows & columns...

Try the following:

Dim values(,) As Integer = {{11, 12}, {21, 22}, {31, 32}}
Dim list As IList = values
For Each item As Object In list
Debug.WriteLine(item)
Next

What values are printed?

The short of it you cannot bind to a two-dimensional array. I would
recommend you convert the two-dimensional array to either a one-dimensional
array, an ArrayList or a DataTable...

Hope this helps
Jay


| Perhaps I have the wrong construct, or misunderstand arrays in vb
(2003)....
| I've loaded a two-dimensional array (168 by 28) into memory as AcctArray.
| {Dim AcctArray (500,28) as string...}
|
| The AcctArray is loaded from a Quickbooks table, so there's no intrinsic
| dataset to assign as datasource....
|
| I want to have a combo table (or list table or whatever), currently named
| cbAccounts, that can scroll through and maybe select items in the array. I
| don't want to display all elements, just columns 1,2,6, and 13...
|
| How do I construct this? A combo box is supposed to have as its datasource
| an "array", but I can't seem to accomplish it. I can do
|
| cbAccounts.Items.Add(AcctArray(j,1) & " " & AcctArray(j,2) & " " &
| Acctarray(j,6) & " " & AcctArray(j,13))
|
| but that doesn't accomplish my objectives...
|
|
| Can someone give me a nudge?
|
| Thanx in advance
|
| --
| Jim Shaffer
|
|