Tablestyle problems

[KC]

Why would the code below fail? I'm making a tablestyle, which works fine. I
test to see if the style already exist for this datagrid, if it does, remove
it before adding the new version. What I don't understand is the 'Contains'
method. I get different answers depending on whether I use:

dgNC.TableStyles.Contains(dgtsNC) or

dgNC.TableStyles.Contains(dgtsNC.MappingName)

I guess I just don't get this tablestyles thing.
-------------------------
Dim dgtsNC As New DataGridTableStyle
Dim dgNC as DataGrid = DataGrid1
...
create a table style
...

If dgNC.TableStyles.Contains(dgtsNC) Then
dgNC.TableStyles.Remove(dgtsNC)
Next
dgNC.TableStyles.Add(dgtsNC)

Ken

[Charlie]

Are you are trying to get different datasources to be displayed in a common
datagrid at different times?

If so, and assuming you are using datatables as your datasources:

When binding the datasource, clear the datagrid's tablestyles collection,
and add the tablestyle needed for the current datasource.

This code covers the basics of setting up tablestyles.

Code:

'Form level objects:
Private DT1 As New DataTable()
Private DT2 As New DataTable()
Private ts1 As New DataGridTableStyle()
Private ts2 As New DataGridTableStyle()

'Put in Form Load event:

'define the 2 datatables that will be used as datasources for grid
DT1.Columns.Add(New DataColumn("FirstName"))
DT1.Columns.Add(New DataColumn("LastName"))
Dim dr As DataRow = DT1.NewRow
dr.Item(0) = "John"
dr.Item(1) = "Smith"
DT1.Rows.Add(dr)
dr = DT1.NewRow
dr.Item(0) = "Mary"
dr.Item(1) = "Jones"
DT1.Rows.Add(dr)

DT2.Columns.Add(New DataColumn("ContactNumber"))
DT2.Columns.Add(New DataColumn("DeviceType"))
dr = DT2.NewRow
dr.Item(0) = "[phone]"
dr.Item(1) = "cell"
DT2.Rows.Add(dr)
dr = DT2.NewRow
dr.Item(0) = "[phone]"
dr.Item(1) = "work fax"
DT2.Rows.Add(dr)

'create 2 tablestyles, one to match each datasource
Dim dgc1 As New DataGridTextBoxColumn()
dgc1.MappingName = "FirstName"
dgc1.HeaderText = "First Name"
ts1.GridColumnStyles.Add(dgc1)
Dim dgc2 = New DataGridTextBoxColumn()
dgc2.HeaderText = "Last Name"
dgc2.MappingName = "LastName"
ts1.GridColumnStyles.Add(dgc2)
ts1.AlternatingBackColor = Color.LightYellow

Dim dgc3 As New DataGridTextBoxColumn()
dgc3.HeaderText = "Contact Number"
dgc3.MappingName = "ContactNumber"
ts2.GridColumnStyles.Add(dgc3)
Dim dgc4 = New DataGridTextBoxColumn()
dgc4.HeaderText = "Type"
dgc4.MappingName = "DeviceType"
ts2.GridColumnStyles.Add(dgc4)
ts2.AlternatingBackColor = Color.MintCream

'create events that set Datagrid's current datasource and tablestyle

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles Button1.Click
DG.TableStyles.Clear()
DG.TableStyles.Add(ts1)
DG.DataSource = DT1
End Sub

Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles Button2.Click
DG.TableStyles.Clear()
DG.TableStyles.Add(ts2)
DG.DataSource = DT2
End Sub
www.charlesfarriersoftware.com


"KC" wrote:

Why would the code below fail? I'm making a tablestyle, which works fine. I
test to see if the style already exist for this datagrid, if it does, remove
it before adding the new version. What I don't understand is the 'Contains'
method. I get different answers depending on whether I use:

dgNC.TableStyles.Contains(dgtsNC) or

dgNC.TableStyles.Contains(dgtsNC.MappingName)

I guess I just don't get this tablestyles thing.
-------------------------
Dim dgtsNC As New DataGridTableStyle
Dim dgNC as DataGrid = DataGrid1
...
create a table style
...

If dgNC.TableStyles.Contains(dgtsNC) Then
dgNC.TableStyles.Remove(dgtsNC)
Next
dgNC.TableStyles.Add(dgtsNC)

Ken

[Dennis]

Try something like the below code (note you should run this check before you
actually add the dgtsNC to your dgNC tablestyles collection:

Dim ts As DataGridTableStyle
Dim foundmapname as boolean
For Each ts In dgNC.TableStyles
if dgNC.MappingName = dgtsNC.MappingName then
foundmapname = True
exit for
end if
next

"KC" wrote:

Why would the code below fail? I'm making a tablestyle, which works fine. I
test to see if the style already exist for this datagrid, if it does, remove
it before adding the new version. What I don't understand is the 'Contains'
method. I get different answers depending on whether I use:

dgNC.TableStyles.Contains(dgtsNC) or

dgNC.TableStyles.Contains(dgtsNC.MappingName)

I guess I just don't get this tablestyles thing.
-------------------------
Dim dgtsNC As New DataGridTableStyle
Dim dgNC as DataGrid = DataGrid1
...
create a table style
...

If dgNC.TableStyles.Contains(dgtsNC) Then
dgNC.TableStyles.Remove(dgtsNC)
Next
dgNC.TableStyles.Add(dgtsNC)

Ken