问题
Adding columns to a GridView programmatically is easy.
There are examples here and here.
Here is a similar question, but it's been answered the same way - to create a datatable and bind it to the GridView.
But won't that remove the original link to the main data source?
My GridView below already has a bind to the sqldatasource below it.
Text="Location Board" Width="100%"></asp:Label>
<asp:GridView ID="gvLocationBoard" runat="server" AllowPaging="True" AllowSorting="True"
AutoGenerateColumns="False" CellPadding="4" DataSourceID="sdsLocationBoard"
ForeColor="#333333" GridLines="None">
<RowStyle BackColor="#F7F6F3" ForeColor="#333333" />
<Columns>
...
...
</Columns>
<FooterStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" />
<PagerStyle BackColor="#284775" ForeColor="White" HorizontalAlign="Center" />
<SelectedRowStyle BackColor="#E2DED6" Font-Bold="True" ForeColor="#333333" />
<HeaderStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" />
<EditRowStyle BackColor="#999999" />
<AlternatingRowStyle BackColor="White" ForeColor="#284775" />
</asp:GridView>
<asp:SqlDataSource ID="sdsLocationBoard" runat="server" ConnectionString="<%$ ConnectionStrings:ATCNTV1ConnectionString %>"
SelectCommand="SELECT rce.RollCallID, v1.StudentID, v1.StudentPreferredName + ' ' + v1.StudentFamilyName AS StudentName, cs.CheckStatusName, rce.DateSubmitted, rce.StaffID, rcp.RollCallPeriod, rcp.PeriodStart, rcp.PeriodEnd FROM vwBoardingTenants AS v1 LEFT OUTER JOIN tblBoardingRollCallEntries AS rce ON rce.StudentID = v1.StudentID LEFT OUTER JOIN tblBoardingCheckStatus AS cs ON cs.CheckStatusID = rce.CheckStatusID LEFT OUTER JOIN tblBoardingRollCallPeriods AS rcp ON rcp.RollCallPeriodID = rce.RollCallPeriodID AND rcp.RowStatus = 1 AND rcp.PeriodYear = YEAR(@SelectedDate) AND dbo.fnDateOnly(@SelectedDate) BETWEEN rcp.PeriodStart AND rcp.PeriodEnd WHERE (dbo.fnDateOnly(rce.DateSubmitted) = dbo.fnDateOnly(@SelectedDate)) AND (v1.Year = YEAR(@SelectedDate))">
<SelectParameters>
<asp:ControlParameter ControlID="txtSelectedDate" Name="SelectedDate" Type="DateTime"/>
</SelectParameters>
</asp:SqlDataSource>
However, what if you're trying to add column headers to a gridview based on a data source that is totally separate (individual) to the main data source, for the overall GridView?
This is my "column" sql datasource...
<asp:SqlDataSource ID="sdsRollCallPeriods" runat="server" ConnectionString="<%$ ConnectionStrings:ATCNTV1ConnectionString %>"
SelectCommand="SELECT RollCallPeriodID, RollCallPeriod, PeriodYear, PeriodStart, PeriodEnd, RowStatus FROM tblBoardingRollCallPeriods WHERE (RowStatus = 1) AND (PeriodYear = @PeriodYear)"
OnSelecting="sdsRollCallPeriods_Selecting">
<SelectParameters>
<asp:Parameter Name="PeriodYear" Type="Int32" />
</SelectParameters>
</asp:SqlDataSource>
What I want to end up with is a Gridview like this ...
The checkboxes on the right and the times, as headers, are the new columns I want to add based on the sdsRollCallPeriods SqlDataSource.
回答1:
Well it's not really a solution, but rather a work-around, and it works for me.
I've added the columns I needed and simply set them all to Visible="false".
<asp:GridView ID="gvLocationBoard" runat="server" AllowPaging="True" AllowSorting="True" ShowFooter="false" ShowHeader="true" Visible="true" AutoGenerateColumns="False" CellPadding="4" ForeColor="#333333" GridLines="None"
DataSourceID="sdsLocationBoard" OnDataBound="gvLocationBoard_DataBound" OnRowDataBound="gvLocationBoard_RowDataBound" PageSize="15">
<RowStyle BackColor="#F7F6F3" ForeColor="#333333" />
<Columns>
<asp:TemplateField HeaderText="RollCallID" InsertVisible="False" SortExpression="RollCallID"
Visible="False">
<ItemTemplate>
<asp:Label ID="Label1" runat="server" Text='<%# Eval("RollCallID") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="StudentID" SortExpression="StudentID" Visible="False">
<ItemTemplate>
<asp:Label ID="Label2" runat="server" Text='<%# Eval("StudentID") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Student" SortExpression="StudentName">
<ItemTemplate>
<asp:Label ID="Label3" runat="server" Text='<%# Eval("StudentName") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Status" SortExpression="CheckStatusName" ItemStyle-HorizontalAlign="Center">
<ItemTemplate>
<asp:Label ID="Label4" runat="server" Text='<%# Eval("CheckStatusName") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="RollCallPeriod0" Visible="False">
<ItemTemplate>
<asp:CheckBox ID="cbRollCallPeriod0" runat="server" />
<asp:HiddenField ID="hfRollCallPeriod0" runat="server" Value='<%# Eval("RollCallPeriod") %>' />
</ItemTemplate>
<HeaderStyle Font-Size="Small" />
<ItemStyle HorizontalAlign="Center" />
</asp:TemplateField>
<asp:TemplateField HeaderText="RollCallPeriod1" Visible="False">
<ItemTemplate>
<asp:CheckBox ID="cbRollCallPeriod1" runat="server" />
<asp:HiddenField ID="hfRollCallPeriod1" runat="server" Value='<%# Eval("RollCallPeriod") %>' />
</ItemTemplate>
<HeaderStyle Font-Size="Small" />
<ItemStyle HorizontalAlign="Center" />
</asp:TemplateField>
..
etc with the RollCallPeriod2, 3, 4 and so on, as many as required.
I then turn them on on Page_Load(), depending on the day's worth of times I require.
DataSourceSelectArguments args = new DataSourceSelectArguments();
DataView dv = sdsRollCallPeriods.Select(args) as DataView;
DataTable dt = dv.ToTable() as DataTable;
if (dt != null)
{
int wsCol = 4; //start of PeriodTimes column in gvLocationBoard
int wsPos = 0;
foreach (DataRow dr in dt.Rows)
{
gvLocationBoard.Columns[wsCol + wsPos].HeaderText = dr.ItemArray[1].ToString();
gvLocationBoard.Columns[wsCol + wsPos].Visible = !gvLocationBoard.Columns[wsCol + wsPos].HeaderText.StartsWith("RollCallPeriod");
wsPos += 1;
}
}
Voila I have my rows and my dynamic columns!
来源：https://stackoverflow.com/questions/35307156/gridview-how-to-add-columns-based-on-data-from-a-separate-data-source