Hi all, i have a window application which make use of a timer class, whereby
every 5 seconds i have to refresh a datagrid,below is the codes

Public Sub TimerFired(ByVal sender As Object, _
ByVal e As System.Timers.ElapsedEventArgs)




'Label1.Text = "Server Time = " & e.SignalTime.ToString
tape()
end sub
Private Function tape()

Dim i As Integer
Dim ds3 As New DataSet
Dim ds4 As New DataSet
ds4 = a.RetrievePatient1()
Dim foodtable As DataTable
Dim idcolumn As DataColumn
Dim namecolumn As DataColumn
Dim foodemandcolumn As DataColumn

Dim row As DataRow
'make a table
foodtable = New DataTable("Food")

'make a column
idcolumn = New DataColumn("PatientID")
idcolumn.DefaultValue = "<PatientID>"
'idcolumn.DataType = Type.GetType("System.string")
foodtable.Columns.Add(idcolumn)

namecolumn = New DataColumn("Name")
idcolumn.DefaultValue = "<Name>"
'idcolumn.DataType = Type.GetType("System.string")
foodtable.Columns.Add(namecolumn)

foodemandcolumn = New DataColumn("DemandFood")
foodemandcolumn.DefaultValue = "<DemandFood>"
'idcolumn.DataType = Type.GetType("System.string")
foodtable.Columns.Add(foodemandcolumn)

'a.RetrievePatient(patID)
'add row of data
For i = 0 To ds4.Tables(0).Rows.Count() - 1
'If TextBox1.Text = ds3.Tables(0).Rows(i)(0) Then
row = foodtable.NewRow
row("PatientID") = ds4.Tables(0).Rows(i)("PatientID")
row("Name") = ds4.Tables(0).Rows(i)("Name")
row("DemandFood") = ds4.Tables(0).Rows(i)("DemandFood")
foodtable.Rows.Add(row)





'DataGrid2.SetDataBindinga(ds2,"DemanfFood)

'End If
Next
ds4.Tables.Add(foodtable)

DataGrid2.SetDataBinding(ds4, "Food")
End Function
With the above coding data could not be retrieve to the datagrid
*datagrid couls br filled if the above codes are placed in a Form_Load or
button_Onclick

vitz...

It looks like every time your timer fires and calls tape() you are adding
another table with the name "food" to your dataset. That should throw a
DuplicateNameException. Remove your old table (or repopulate it instead of
creating a new one) before you try and retrieve new data.

"vita" wrote:

> Hi all, i have a window application which make use of a timer class, whereby
> every 5 seconds i have to refresh a datagrid,below is the codes
>
> Public Sub TimerFired(ByVal sender As Object, _
> ByVal e As System.Timers.ElapsedEventArgs)
>
>
>
>
> 'Label1.Text = "Server Time = " & e.SignalTime.ToString
> tape()
> end sub
> Private Function tape()
>
> Dim i As Integer
> Dim ds3 As New DataSet
> Dim ds4 As New DataSet
> ds4 = a.RetrievePatient1()
> Dim foodtable As DataTable
> Dim idcolumn As DataColumn
> Dim namecolumn As DataColumn
> Dim foodemandcolumn As DataColumn
>
> Dim row As DataRow
> 'make a table
> foodtable = New DataTable("Food")
>
> 'make a column
> idcolumn = New DataColumn("PatientID")
> idcolumn.DefaultValue = "<PatientID>"
> 'idcolumn.DataType = Type.GetType("System.string")
> foodtable.Columns.Add(idcolumn)
>
> namecolumn = New DataColumn("Name")
> idcolumn.DefaultValue = "<Name>"
> 'idcolumn.DataType = Type.GetType("System.string")
> foodtable.Columns.Add(namecolumn)
>
> foodemandcolumn = New DataColumn("DemandFood")
> foodemandcolumn.DefaultValue = "<DemandFood>"
> 'idcolumn.DataType = Type.GetType("System.string")
> foodtable.Columns.Add(foodemandcolumn)
>
> 'a.RetrievePatient(patID)
> 'add row of data
> For i = 0 To ds4.Tables(0).Rows.Count() - 1
> 'If TextBox1.Text = ds3.Tables(0).Rows(i)(0) Then
> row = foodtable.NewRow
> row("PatientID") = ds4.Tables(0).Rows(i)("PatientID")
> row("Name") = ds4.Tables(0).Rows(i)("Name")
> row("DemandFood") = ds4.Tables(0).Rows(i)("DemandFood")
> foodtable.Rows.Add(row)
>
>
>
>
>
> 'DataGrid2.SetDataBindinga(ds2,"DemanfFood)
>
> 'End If
> Next
> ds4.Tables.Add(foodtable)
>
> DataGrid2.SetDataBinding(ds4, "Food")
> End Function
> With the above coding data could not be retrieve to the datagrid
> *datagrid couls br filled if the above codes are placed in a Form_Load or
> button_Onclick
>
> vitz...