Hi,
If the default grid filtering experience (see here and here) does not match your needs, you can also consider another built-in integration - with RadFilter: https://demos.telerik.com/aspnet-ajax/filter/examples/integration/defaultcs.aspx?product=filter.
If you would still like to proceed with custom filtering, I advise that you consider filtering the data source itself rather than hacking through the grid. You can easily do that in the NeedDataSource event by processing the data according to the desired logic before passing it to the grid.
Doing this manually is actually going to be rather hard and the provided code will have a lot of limitations. Nevertheless, I modified it so you can get started, and I also left comments with the issues and resources you can use to get things done:
Protected Sub ItemCommand(ByVal sender As Object, ByVal e As GridCommandEventArgs)
Dim filterExpression As String = String.Empty
If e.CommandName = "FilterAll" Then
Dim cmdItem As GridCommandItem = calendarTableView.MasterTableView.GetItems(GridItemType.CommandItem)(0)
'TryCast(e.Item, GridCommandItem)
Dim txtFilter = TryCast(cmdItem.FindControl("txtFilter"), TextBox)
'these loops are unnecessary, it is similar to the operation that needs to be done on the data source for filtering anyway
'also,they will only go through the data on the current page as the grid creates items only for the current page (for performance reasons)
'which is why such custom filtering is best implemented over the data source rather than hacking through the grid
'also, with this code the filter expression will be applied only for the last column where a text occurence exists
For Each col As GridColumn In calendarTableView.MasterTableView.Columns
For Each dataItem As GridDataItem In calendarTableView.Items
If dataItem(col.UniqueName).Text.Contains(txtFilter.Text) Then
'sample to aim for
'@"it[""CustomerID""].ToString().Contains(""ALFKI"")"
filterExpression = "it[""" + col.UniqueName + """].ToString().Contains(""" + txtFilter.Text + """)"
calendarTableView.MasterTableView.FilterExpression = filterExpression
End If
Next
Next
If (Not String.IsNullOrEmpty(filterExpression)) Then
'if you won't be doing operations on the grid, you do not really need to rebind it
calendarTableView.MasterTableView.Rebind()
End If
ElseIf e.CommandName = "ClearFilter" Then
Dim cmdItem As GridCommandItem = calendarTableView.MasterTableView.GetItems(GridItemType.CommandItem)(0)
'Dim cmdItem As GridCommandItem = TryCast(e.Item, GridCommandItem)
Dim txtFilter As TextBox = TryCast(cmdItem.FindControl("txtFilter"), TextBox)
txtFilter.Text = String.Empty
For Each col As GridColumn In calendarTableView.MasterTableView.Columns
col.ListOfFilterValues = Nothing
col.CurrentFilterFunction = GridKnownFunction.NoFilter
col.CurrentFilterValue = String.Empty
Next
calendarTableView.MasterTableView.FilterExpression = String.Empty
End If
End Sub
Protected Function GetTestData() As DataTable
Dim tbl As New DataTable()
tbl.Columns.Add(New DataColumn("someField", GetType(String)))
tbl.Columns.Add(New DataColumn("otherField", GetType(String)))
tbl.Columns.Add(New DataColumn("thirdField", GetType(Integer)))
tbl.Columns.Add(New DataColumn("fourthField", GetType(String)))
tbl.Rows.Add(New Object() {"first", "firstRecord2", 1, "A"})
tbl.Rows.Add(New Object() {"first", "secondRecord2", 2, "B"})
tbl.Rows.Add(New Object() {"third", "thirdRecord2", 3, "C"})
Return tbl
End Function
Protected Sub calendarTableView_NeedDataSource(sender As Object, e As GridNeedDataSourceEventArgs)
DirectCast(sender, RadGrid).DataSource = GetTestData()
End Sub
Regards,
Marin Bratanov
Progress Telerik
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