Question

I have a gridview control with a checkbox field and several bound fields. The checkbox field does not directly map to a field in the database. Rather, i want to read a value from a field in the database and “check” some of the checkboxes.

For example, given the following data from the database -> datatable

        PROCESSED   NAME             DATE            
            Y       Mickey Mouse     11/15/2011
            N       Donald Duck      4/01/2012
            Y       James Bond       5/02/2011

I would like the gridview to display a checkbox and set the value of boxes to UNCHECKED where PROCESSED = N and for PROCESSED = Y either have an uneditable checkbox or no checkbox at all.

        PROCESSED   NAME             DATE            
           [/]       Mickey Mouse     11/15/2011
           [ ]       Donald Duck      4/01/2012
           [/]       James Bond       5/02/2011

To populate the gridview, a SQL stmt is run against a database, and the result of the SQL query is stored in a datatable. Before binding the datatable to the gridview, i would like to check the “processed” field and set the checkbox based on that value.

Here is the gridview control (shortened for clarity):

<asp:GridView ID="gridview_all_applicants" runat="server" AllowPaging="True">
        <Columns>
          <asp:TemplateField HeaderText="Complete">
                <ItemTemplate>
                    <asp:CheckBox ID="process_flag" runat="server" />
                </ItemTemplate>
          </asp:TemplateField>
          <asp:BoundField DataField="lastname" HeaderText="Last Name" ReadOnly="True"  SortExpression="lastname" />

Here is what i have so far in the code behind

 SqlCommand cmd = new SqlCommand(sql query here);
 SqlDataAdapter da = new SqlDataAdapter();
 DataTable dt = new DataTable();
 da.SelectCommand = cmd;
 // Save results of select statement into a datatable
 da.Fill(dt);
 foreach (DataRow r in dt.Rows)
 {
        // do some processing of data returned from query
        // read the char value from the returned data and set checkbox

             procflag = r["process_flag"].ToString().ToLower();
             CheckBox chkbox = new CheckBox();
             if (procflag == null || procflag == "n")
             {
                // SET CHECKBOX TO "NOT CHECKED"        

              }
              else
              {
                 // SET CHECKBOX TO "CHECKED" AND MAKE IT UNCLICKABLE
                 // ----OR---- DO NOT DISPLAY CHECKBOX AT ALL.

               }
     } // end for each


          gridview_all_applicants.DataSource = dt;
          gridview_all_applicants.DataBind(); 

any help is greatly appreciated.

Answer 1

You can do it like this:

First in sql server:

SELECT 
    CAST(CASE PROCESSED WHEN 'Y' THEN 1 ELSE 0 END AS BIT) AS PROCESSED
    NAME
    DATE
FROM ExampleTable

in c# code:

SqlCommand cmd = new SqlCommand(sql query here); 
SqlDataAdapter da = new SqlDataAdapter(); 
DataTable dt = new DataTable(); 
da.SelectCommand = cmd; 

// Save results of select statement into a datatable 
da.Fill(dt);

gridview_all_applicants.DataSource = dt;          
gridview_all_applicants.DataBind(); 

and finally in aspx:

<asp:TemplateField HeaderText="Complete">
<ItemTemplate>
    <asp:CheckBox ID="process_flag" runat="server" Checked='<%# bool.Parse(Eval("PROCESSED").ToString()) %>' Enable='<%# !bool.Parse(Eval("PROCESSED").ToString()) %>'/>
</ItemTemplate>