Format BoundField Data Types Dynamically
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24-01-2021 - |
Pergunta
I'm using a CheckBoxList to define which columns are displayed in a GridView. I populate the CheckBoxList using a query like
select column_name, data_type from information_schema.columns
where table_name = 'myTable'
After the user has chosen the columns (with various Data Types in them) they wish to display, they press a button and the following snippet of VB code generates the GridView.
For Each item As ListItem In chooseColsList.Items
If item.Selected Then
Dim bf As New BoundField()
'PRODUCES BUGGY RESULTS BECAUSE APPLIED TO ALL BoundFields
bf.DataFormatString = "{0:dd-MMM-yyyy}"
bf.ApplyFormatInEditMode = True
bf.DataField = item.Value
bf.HeaderText = item.Value
bf.SortExpression = item.Value
statusReportGrid.Columns.Add(bf)
End If
Next
What I want to do is to apply the DataFormatString ONLY to the columns with a 'date' Data Type in them. However, I have found no way of programmatically determining the Type of the data in the column being bound, no any way of passing this info to the Control. This information exists in the information_schema, as shown in my query, but I don't know how to extract that out and use it to dynamically setup my BoundFields. It is important to note that I'm using an SqlDataSource.
I've experimented with just about every possible solution I can think of and end up here.
Thanks in advance for your help, it is VERY appreciated :)
Solução
If you set your check box list like this:
<asp:checkboxlist id="list" runat="server"
DataTextField="column_name" DataValueField="data_type" DataSourceID="YourDSID" />
You should be able to iterate through the items and check the value of the current Item like so:
For Each item As ListItem In chooseColsList.Items
If item.Selected Then
Dim bf As New BoundField()
If StrComp(item.Value,"date") = 0 Then 'Or however datetime is returned
bf.DataFormatString = "{0:dd-MMM-yyyy}"
bf.ApplyFormatInEditMode = True
End If
bf.DataField = item.Text
bf.HeaderText = item.Text
bf.SortExpression = item.Text
statusReportGrid.Columns.Add(bf)
End If
Next