Question

PLEASE HELP ME TO SOLVE THIS ERROR

cs file

public partial class Control : System.Web.UI.Page
{



    protected void Page_Load(object sender, EventArgs e)
{
    OrderDataRepository rep = new OrderDataRepository();

    var results = rep.GetAllOrderData().
                  GroupBy(o => o.DRIVER_ID).
                  Select(g =>
                            new
                            {
                                DriverId = g.Key,
                                OrderCount = g.Count(),
                                OrderCountWhereNameIsNotNull = 
                                                  g.Count(o => o.RECEIVE_NAME != null)
                            }).ToList();

    DataViewer.DataSource = results;
    DataViewer.DataBind();
}

}

aspx file

<asp:GridView ID="DataViewer" runat="server">
    <Columns>
        <TemplateColumn>
            <ItemTemplate>
<div style='width: <%# Eval("OrderCount") %>' />
            </ItemTemplate>
        </TemplateColumn>
    </Columns>
</asp:GridView>

Parser Error Description: An error occurred during the parsing of a resource required to service this request. Please review the following specific parse error details and modify your source file appropriately. Parser Error Message: System.Web.UI.WebControls.DataControlFieldCollection must have items of type ‘System.Web.UI.WebControls.DataControlField’. ‘TemplateColumn’ is of type ‘System.Web.UI.HtmlControls.HtmlGenericControl

  int OrderCount, OrderCountWhereNameIsNotNull;
System.Web.UI.WebControls.TableRow oRow;
System.Web.UI.WebControls.TableCell oCell;
System.Web.UI.HtmlControls.HtmlGenericControl oDiv;

while (true)
//loop through records
//do while not eof
{
    oRow = new System.Web.UI.WebControls.TableRow();
    oCell = new System.Web.UI.WebControls.TableCell();
    oDiv = new System.Web.UI.HtmlControls.HtmlGenericControl("DIV");
    OrderCount = 200; //get value from DB, convert to meaningful width
    OrderCountWhereNameIsNotNull = 100; //get value from DB, convert to meaningful width

    oDiv.InnerHtml = "<div style='border: 3px solid black; width: " + OrderCount + "px;'>";
    oDiv.InnerHtml += Environment.NewLine + "  <div style='border: 0px; background-color: red; width: " + OrderCountWhereNameIsNotNull + "px;'>&nbsp;</div>";
    oDiv.InnerHtml += Environment.NewLine + "</div>";
    oCell.Controls.Add(oDiv);
    oRow.Cells.Add(oCell);
    tblData.Rows.Add(oRow);
}

Answer 1

Change this

aspx file

<asp:GridView ID="DataViewer" runat="server">
    <Columns>
        <TemplateColumn>
            <ItemTemplate>
<div style='width: <%# Eval("OrderCount") %>' />
            </ItemTemplate>
        </TemplateColumn>
    </Columns>
</asp:GridView>

to this

aspx file

<asp:GridView ID="DataViewer" runat="server">
    <Columns>
        <ItemTemplate>
<div style='width: <%# Eval("OrderCount") %>' />
        </ItemTemplate>
    </Columns>
</asp:GridView>

Explanation: The error message does in fact tell you what’s wrong, although it’s cryptic if you don’t know what it means! Here’s a breakdown:

Parser Error Description: An error occurred during the parsing of a resource required to service this request.

This means that something went wrong while the ASP.NET engine was examining a source file. The hints are ‘request’ (as in, a web request was made) and ‘during the parsing of a resource’.

Please review the following specific parse error details and modify your source file appropriately.

The error is in a file parsed by asp.net, not the C# compiler. This means the problem is in the aspx, not a .cs file.

Parser Error Message: System.Web.UI.WebControls.DataControlFieldCollection must have items of type ‘System.Web.UI.WebControls.DataControlField’. ‘TemplateColumn’ is of type ‘System.Web.UI.HtmlControls.HtmlGenericControl

Here, something is expecting to contain things which are DataControlFields, but you’ve given it a TemplateColumn, which is a HtmlGenericControl (which isn’t a DataControlField, so isn’t what it wants). So we examine the aspx markup and say, where is there a TemplateControl? And we see that your GridView\Columns collection has a TemplateControl. Whereas (on checking the help) it should be directly containing an ItemTemplate, when you want a templated column. And we’re done.