What's the MappingName for a Collection?

[trebor]

I bind a collection to a data grid, and it works okay, but when I try to
create customized columns, it just doesn't work. Here is the code. Note
that if I uncomment that section below, and use "DT" as the mapping
name, it works fine. But I don't want to have to copy the collection to
the data table every time.

I searched Google and keep reading that you have to use "the classname
of the collection," but nothing I use as a mapping name gives me any
results. I just get a blank datagrid. Thanks for any suggestions.

=== code

Module x
Global objElecMotor as clsElecMotor
Global ElecMotors As New Collection()
End Module

Public Class frmList
Inherits System.Windows.Forms.Form

Private Sub frmList_Load(ByVal sender As Object, _
ByVal e As System.EventArgs) Handles MyBase.Load

Dim Column1 As New DataGridTextBoxColumn()
Column1.MappingName = "MotorID"
Column1.HeaderText = "ID"
Column1.Width = 40

Dim Column2 As New DataGridTextBoxColumn()
Column2.MappingName = "Description"
Column2.HeaderText = "Desc"
Column2.Width = 100

Dim Column3 As New DataGridTextBoxColumn()
Column3.MappingName = "RPM"
Column3.HeaderText = "RPM"
Column3.Width = 40

Dim Column4 As New DataGridTextBoxColumn()
Column4.MappingName = "Voltage"
Column4.HeaderText = "Volts"
Column4.Width = 30

Dim Column5 As New DataGridTextBoxColumn()
Column5.MappingName = "Status"
Column5.HeaderText = "STS"
Column5.Width = 40

Dim NewStyle As New DataGridTableStyle()
NewStyle.MappingName = "?????????????"
NewStyle.GridColumnStyles.Add(Column1)
NewStyle.GridColumnStyles.Add(Column2)
NewStyle.GridColumnStyles.Add(Column3)
NewStyle.GridColumnStyles.Add(Column4)
NewStyle.GridColumnStyles.Add(Column5)

'Dim dt As New DataTable("DT")
'dt.Columns.Add("MotorID", Type.GetType("System.String"))
'dt.Columns.Add("Description", Type.GetType("System.String"))
'dt.Columns.Add("RPM", Type.GetType("System.Int32"))
'dt.Columns.Add("Voltage", Type.GetType("System.Int32"))
'dt.Columns.Add("Status", Type.GetType("System.String"))

'Dim obj As clsElecMotor
'For Each obj In ElecMotors
' dt.Rows.Add(New Object() {obj.MotorID, obj.Description, _
obj.RPM, obj.Voltage, obj.Status})
'Next
'DataGrid.DataSource = dt

DataGrid.TableStyles.Clear()
DataGrid.TableStyles.Add(NewStyle)
End Sub

[Ken Tucker [MVP]]

Hi,

Use Arraylist as the mappingname if you are binding to an arraylist.
Use Collection if you are binding to a collection. Remeber the datagrid will
only show properties.

Dim arBind As New Collection

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles MyBase.Load

Dim x As Integer

For x = 0 To 20

Dim cls As New BindTo

cls.Col1 = x.ToString

cls.Col2 = Chr(65 + x)

arBind.Add(cls)

Next

SetupGrid()

DataGrid1.DataSource = arBind

End Sub

Private Sub SetupGrid()

Dim ts As New DataGridTableStyle

ts.MappingName = "Collection"

Dim colDescription As New DataGridTextBoxColumn

With colDescription

..MappingName = "Col2"

..HeaderText = "Description"

..Width = 240

..NullText = ""

End With

Dim colQty As New DataGridTextBoxColumn

With colQty

..MappingName = "Col1"

..HeaderText = "Qty"

..Width = 50

End With

ts.GridColumnStyles.Add(colDescription)

ts.GridColumnStyles.Add(colQty)

DataGrid1.TableStyles.Add(ts)

ts = Nothing

colQty = Nothing

colDescription = Nothing

End Sub

End Class

Public Class BindTo

Private mstrCol1 As String

Private mstrCol2 As String

Public Property Col1() As String

Get

Return mstrCol1

End Get

Set(ByVal Value As String)

mstrCol1 = Value

End Set

End Property

Public Property Col2() As String

Get

Return mstrCol2

End Get

Set(ByVal Value As String)

mstrCol2 = Value

End Set

End Property

End Class

Ken
--------------
"tr****@sirius.com.no.more" <us**@example.com> wrote in message
news:bg********************************@news.super news.com...

I bind a collection to a data grid, and it works okay, but when I try to
create customized columns, it just doesn't work. Here is the code. Note
that if I uncomment that section below, and use "DT" as the mapping
name, it works fine. But I don't want to have to copy the collection to
the data table every time.

I searched Google and keep reading that you have to use "the classname
of the collection," but nothing I use as a mapping name gives me any
results. I just get a blank datagrid. Thanks for any suggestions.

=== code

Module x
Global objElecMotor as clsElecMotor
Global ElecMotors As New Collection()
End Module

Public Class frmList
Inherits System.Windows.Forms.Form

Private Sub frmList_Load(ByVal sender As Object, _
ByVal e As System.EventArgs) Handles MyBase.Load

Dim Column1 As New DataGridTextBoxColumn()
Column1.MappingName = "MotorID"
Column1.HeaderText = "ID"
Column1.Width = 40

Dim Column2 As New DataGridTextBoxColumn()
Column2.MappingName = "Description"
Column2.HeaderText = "Desc"
Column2.Width = 100

Dim Column3 As New DataGridTextBoxColumn()
Column3.MappingName = "RPM"
Column3.HeaderText = "RPM"
Column3.Width = 40

Dim Column4 As New DataGridTextBoxColumn()
Column4.MappingName = "Voltage"
Column4.HeaderText = "Volts"
Column4.Width = 30

Dim Column5 As New DataGridTextBoxColumn()
Column5.MappingName = "Status"
Column5.HeaderText = "STS"
Column5.Width = 40

Dim NewStyle As New DataGridTableStyle()
NewStyle.MappingName = "?????????????"
NewStyle.GridColumnStyles.Add(Column1)
NewStyle.GridColumnStyles.Add(Column2)
NewStyle.GridColumnStyles.Add(Column3)
NewStyle.GridColumnStyles.Add(Column4)
NewStyle.GridColumnStyles.Add(Column5)

'Dim dt As New DataTable("DT")
'dt.Columns.Add("MotorID", Type.GetType("System.String"))
'dt.Columns.Add("Description", Type.GetType("System.String"))
'dt.Columns.Add("RPM", Type.GetType("System.Int32"))
'dt.Columns.Add("Voltage", Type.GetType("System.Int32"))
'dt.Columns.Add("Status", Type.GetType("System.String"))

'Dim obj As clsElecMotor
'For Each obj In ElecMotors
' dt.Rows.Add(New Object() {obj.MotorID, obj.Description, _
obj.RPM, obj.Voltage, obj.Status})
'Next
'DataGrid.DataSource = dt

DataGrid.TableStyles.Clear()
DataGrid.TableStyles.Add(NewStyle)
End Sub

[trebor]

"Ken Tucker [MVP]" <vb***@bellsouth.net> wrote:

Use Arraylist as the mappingname if you are binding to an arraylist.
Use Collection if you are binding to a collection.

Thanks for the code. I've checked that it does what I want, and now I'll
see why my code doesn't.