Here is a little example to doing multple joins using LINQ with EF:

var query = context.EquipmentBases

  .Where(e => e.Model == model && e.Serial == serial && e.Suffix == suffix)

  .Join(context.TruckBases, e=>e.EquipmentBaseID, t =>t.EquipmentBaseFK, (e,t)=>new{e,t})

  .Join(context.TruckSupplemental_Hitch, et=>et.t.TruckID, h=>h.TruckFK, (et,h)=>new{et,h})

  .Join(context.TrailerPlugTypeLTs, eth=>eth.et.t.TrailerPlugTypeFK, p=>p.ID, (eth, p)=>new{eth,p})

  .Select(r => new { r.eth.et.e.CurbWeight, r.eth.et.e.MaxLoad, r.eth.h.BallRating, r.eth.h.ReceiverRating, r.eth.h.BallSize, r.eth.et.e.GVWR, r.eth.h.BallHeight, r.eth.et.t.IntegratedHitchSystem, r.p.TrailerPlugType });

Note the pattern in the joins. This is what makes it all work.

How can the width of an edit text box be set in a GridView control where EnableSortingAndPagingCallback is true? Microsoft’s documentation for GridView.EnableSortingandPagingCallbacks states "If the Columns collection contains a column that does not support callbacks, such as TemplateField, a NotSupportedException exception is raised." So this rules out the use of a template column. I tried the template column and found it caused an error as advertised. I posted this question on Express Exchange but received only one bogus response.

Here is my GridView code…

<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" Width="100%"
            AllowSorting="True" AllowPaging="true" PageSize="12"   
            PagerSettings-Mode="Numeric"
            OnRowDataBound="BlackberryView_OnRowDataBound"
            EnableSortingAndPagingCallbacks="True" EmptyDataText="No records found!"
            DataSourceID="SqlDataSource1" AutoGenerateEditButton="True"
            OnRowUpdating="BlackberryView_OnRowUpdating"  EditRowStyle-Width="100%">
            <HeaderStyle CssClass="blackberryviewheader" ForeColor="White" Wrap="False" />
            <RowStyle CssClass="blackberryviewrow" ForeColor="#003366"  />
            <AlternatingRowStyle CssClass="blackberryviewalternatinfrow" />
            <EditRowStyle BackColor="Red" Width="100%" />
            <PagerStyle ForeColor="#003366" Font-Bold="true" HorizontalAlign="Center" />
        </asp:GridView>

After much searching of the internet, and only one bogus response from "Experts Exchange" I set to work my to solve the problem myself. Here is my work around…

• Create a integer variable, editRow, and set its value to -2
• When the OnEditRowEditing event fires, set editRow to the value of the selected row index.
• As the ViewGrid re-builds, check for the row selected for editing. When found, check the specific cell for an empty string. If the cell contains a text box control the cell Text value will be "".
• Next cast the cell’s first control to a TextBox then you can set its various properties including it’s width.

Int32 editRow = -2;

protected void GridView1_OnRowDataBound(Object sender, GridViewRowEventArgs e)
{
        TextBox tb = null;
        if (e.Row.RowIndex == editRow)
        {
            sVal = e.Row.Cells[2].Text;
            if (e.Row.Cells[2].Text == "")
            {
                tb = (TextBox)e.Row.Cells[2].Controls[0];
                tb.Wrap = true;
                tb.Width = Unit.Pixel(740);
                tb.Rows = 4;
                tb.TextMode = TextBoxMode.MultiLine;
                tb.Height = Unit.Pixel(60);
            }
       }
}

protected void GridView1_OnRowEditing(object sender, GridViewEditEventArgs e)
{
    editRow = e.NewEditIndex;
}