DataGrid hiding Columns in A DataGrid
One of the frequently asked questions over at Asplists.com are: "How does I hide a column in a DataGrid?". One very important point to "that" you cannot hide autogenerated columns in a data grid. The reason is autogenerated columns are not added to the DataGrid ' s DataGridColumn collection. So, in order for a column to is hidden it must is either programmatically added to the DataGrid at runtime or explicitly d efined (using templates) at the AutoGenerateColumns property set to False (the code in this article would Use this method).
This is Article provides sample code to hide a column (could easily is modified to hide more) for two different IDing columns in response to a event on the page (common in Web reports) or hiding columns to provide different Lity based on the security levels.
A, let's look at how we can hide and show a column in a DataGrid in response to an event (the click of a button) on th E page. You can have a live example here.
The code:
<%@ Page language= "VB"%>
<%@ Import namespace= "System.Data"%>
<%@ Import namespace= "System.Data.SqlClient"%>
<script runat= "Server" >
Sub Page_Load (Sender as Object, E as EventArgs)
Dim MyConnection As SqlConnection = New _
SqlConnection ("Data source= (local) \NetSDK;" Trusted_connection=yes; Initial catalog=pubs ")
Dim mycommand as SqlCommand = New SqlCommand ("Select * from Publishers", MyConnection)
Myconnection.open ()
Mydatagrid.datasource = Mycommand.executereader (commandbehavior.closeconnection)
Mydatagrid.databind ()
End Sub
Sub Hideshow_click (Sender as Object, E as EventArgs)
If mydatagrid.columns (0). Visible = False Then
Mydatagrid.columns (0). Visible = True
Else
Mydatagrid.columns (0). Visible = False
End If
End Sub
</script>
<body>
<form runat= "Server" >
<asp:datagrid id= "Mydatagrid" width= "25%" autogeneratecolumns= "false" runat= "Server" >
<Columns>
<asp:templatecolumn headertext= "Publisher ' s ID" >
<ItemTemplate>
<span><%# Container.DataItem ("pub_id")%></span>
</ItemTemplate>
</asp:TemplateColumn>
<asp:templatecolumn headertext= "Publisher ' s Name" >
<ItemTemplate>
<span><%# Container.DataItem ("pub_name")%></span>
</ItemTemplate>
</asp:TemplateColumn>
<asp:templatecolumn headertext= "City" >
<ItemTemplate>
<span><%# Container.DataItem ("City")%></span>
</ItemTemplate>
</asp:TemplateColumn>
<asp:templatecolumn headertext= "State" >
<ItemTemplate>
<span><%# Container.DataItem ("state")%></span>
</ItemTemplate>
</asp:TemplateColumn>
<asp:templatecolumn headertext= "Country" >
<ItemTemplate>
<span><%# Container.DataItem ("Country")%></span>
</ItemTemplate>
</asp:TemplateColumn>
</Columns>
</asp:DataGrid>
<asp:button id= "Hideshow" text= "Hide/show" onclick= "Hideshow_click" runat= "Server"/>
</form>
</body>
Next, let's look at how we can hide a column in a DataGrid based to the security level of the user. This example isn't *actually* secure and security isn't discussed in this article-we are the to show how to hide Da Tagrid columns to secure a page! The code below checks a querystring parameter called ' Security ' is the page loads. If ' security ' equals ' Admin ' then all of the columns are displayed. If ' security ' equals anything other than "Admin" then the "the" the "the" the "the", "the" is hidden.
Click here to view the DataGrid with no priveleges. (No pub_id column)
Click here to view the DataGrid with Admin priveleges. (All columns visible)
The code:
<%@ Page language= "VB"%>
<%@ Import namespace= "System.Data"%>
<%@ Import namespace= "System.Data.SqlClient"%>
<script runat= "Server" >
Sub Page_Load (Sender as Object, E as EventArgs)
Dim MyConnection As SqlConnection = New _
SqlConnection ("Data source= (local) \NetSDK;" Trusted_connection=yes; Initial catalog=pubs ")
Dim mycommand as SqlCommand = New SqlCommand ("Select * from Publishers", MyConnection)
Myconnection.open ()
Mydatagrid.datasource = Mycommand.executereader (commandbehavior.closeconnection)
Mydatagrid.databind ()
If Request.QueryString ("security") = "Admin" Then
Mydatagrid.columns (0). Visible = False
End If
End Sub
</script>
<body>
<form runat= "Server" >
<asp:datagrid id= "Mydatagrid" autogeneratecolumns= "false" runat= "Server" >
<Columns>
<asp:templatecolumn headertext= "Publisher ' s ID" >
<ItemTemplate>
<span><%# Container.DataItem ("pub_id")%></span>
</ItemTemplate>
</asp:TemplateColumn>
<asp:templatecolumn headertext= "Publisher ' s Name" >
<ItemTemplate>
<span><%# Container.DataItem ("pub_name")%></span>
</ItemTemplate>
</asp:TemplateColumn>
<asp:templatecolumn headertext= "City" >
<ItemTemplate>
<span><%# Container.DataItem ("City")%></span>
</ItemTemplate>
</asp:TemplateColumn>
<asp:templatecolumn headertext= "State" >
<ItemTemplate>
<span><%# Container.DataItem ("state")%></span>
</ItemTemplate>
</asp:TemplateColumn>
<asp:templatecolumn headertext= "Country" >
<ItemTemplate>
<span><%# Container.DataItem ("Country")%></span>
</ItemTemplate>
</asp:TemplateColumn>
</Columns>
</asp:DataGrid>
</form>
</body>
