I'm trying to figure out how to populate a combo box but I need to be able to set a DatasourceKey in the autopopulate settings and cannot.  When I try to manually populate the control I get data but as soon as you select an item the entire form locks and you cannot set focus to any other controls.  I'm completely lost as to why the combobox locks the form.

I'm frustrated that I cannot set the DatasourceKey for the population business object, and that I cannot find any examples for manually populating a business object.  All the documentation says to 'search for combobox population', and a vague reference to needing a datatable but no specifics for required fields.  Which seems odd since you populate a combobox with objects not datatables, or is there some interface the combobox items needs to support?

Jason

Jason Seidell

Programmer/Analyst

Infinedi

Well I at least found a good example on MSDN of how to populate a combo-box with items and get it to use the SelectedValue property for binding to the SF BO.   http://msdn.microsoft.com/en-us/library/system.windows.forms.listcontrol.valuemember.aspx

First I created a class to hold my items

Public Class ComboBoxItem(Of T)
Private _description As String
Private _value As T
''' <summary>
''' Initializes a new instance of the ComboBoxItem class.
''' </summary>
Public Sub New()
_description = String.Empty
End Sub
''' <summary>
''' Initializes a new instance of the ComboBoxItem class.
''' </summary>
Public Sub New(ByVal Description As String, ByVal Value As T)
Me.Description = Description
Me.Value = Value
End Sub
Public Overrides Function ToString() As String
Return String.Format("{0} ({1})", Description, Value)
End Function
Public Property Description() As String
Get
Return _description
End Get
Set(ByVal value As String)
_description = value
End Set
End Property
Public Property Value() As T
Get
Return _value
End Get
Set(ByVal value As T)
_value = value
End Set
End Property
End Class

Then on Form Load I run a function to populate

Dim elecPayers As New Infinedi.BO.Processing.Enrollment.ElectronicPayer_BO()
elecPayers.DataSourceKey = enrollmentDS.DatasourceKey
elecPayers.FillAll()
Dim elecPayerList As New ArrayList()
 
For i As Integer = 0 To elecPayers.Count - 1
elecPayers.MoveAbsolute(i)
elecPayerList.Add(New ComboBoxItem(Of Integer)(elecPayers.Name, elecPayers.ElectronicPayerID))
Next i
 
cmbElectronicPayerId.DataSource = elecPayerList
cmbElectronicPayerId.DisplayMember = "Description"
cmbElectronicPayerId.ValueMember = "Value"

So I'm at least to a point where I can move on and get it working, but I would still like to know why there isn't a property or field in the PopulationDataSourceSettings() to let me set the DatasourceKey instead of defaulting to a '' datasource key.

Jason Seidell

Programmer/Analyst

Infinedi

Hi Jason,



Couple of thing to clarify...



Combobox does not use a data source key, the key is assigned to the business object which is the one responsible to get the data. With this in mind this is how I setup my comboboxes:

1.- I drop an instance of the BO which will be used in the combobox.

2.- In the combobox set the following properties as follow:

a: PopulateOnFormLoad = Manual

b: PopulationDatasourceSettings:

i: Method to Execute: CopyDataFrom(BuisnessLayerBase,BusinessCloneDataType)

3.- In the ListPopluating add code to copy the data from the form's bo to the combo



Now, you need to manually at some point fill the form's bo with the correct data, then just requery() the combobox.



Make sure you use the desired DataSourceKey in the BO class or instance in the form.

Edhy Rijo