获取gridview的页脚行单元格值

Question

I have a gridview with two textboxes in the footer. What's required is get the textbox values, store it to a datatable and then bind the same to the gridview. I am unable to get the textbox values. They show up empty (as you can see). Where am I going wrong.

ASPX:

<asp:GridView ID="gv" runat="server" AutoGenerateColumns="False" 
ShowFooter="true" OnRowDataBound="gv_RowDataBound"  
OnRowCommand="gv_RowCommand">           
 <Columns>
  <asp:TemplateField>
   <ItemTemplate>
    <asp:LinkButton ID="lnkEdit" runat="server" Text="Edit" CommandName="Edit">
</asp:LinkButton>
  </ItemTemplate>
  <EditItemTemplate>
   <asp:LinkButton ID="lnkUpdate" runat="server" Text="Update" 
CommandName="Update"></asp:LinkButton>
   &nbsp;<asp:LinkButton ID="lnkCancel" runat="server" Text="Cancel"  
   CommandName="Cancel"></asp:LinkButton>
   </EditItemTemplate>
   </asp:TemplateField>
   <asp:TemplateField HeaderText="S.No">
     <ItemTemplate>
       <%#Container.DataItemIndex %>
     </ItemTemplate>
     </asp:TemplateField>
     <asp:TemplateField HeaderText="ID">
       <ItemTemplate>
       <asp:Label ID="lbId" runat="server" Text='<%#Eval("id") %>'></asp:Label>
       </ItemTemplate>
    <EditItemTemplate>
     <asp:TextBox ID="txtId" runat="server" Text='<%#Eval("id") %>'>
     </asp:TextBox>
     </EditItemTemplate>
     <FooterTemplate>
     <asp:TextBox ID="txtNewId" runat="server"></asp:TextBox>
    <asp:RequiredFieldValidator runat="server" ControlToValidate="txtNewId" 
     SetFocusOnError="true"
    ErrorMessage="*" ForeColor="Red"></asp:RequiredFieldValidator>
    </FooterTemplate>
    </asp:TemplateField>
    <asp:TemplateField HeaderText="NAME">
    <ItemTemplate>
    <asp:Label ID="lbName" runat="server" Text='<%#Eval("name") %>'></asp:Label>
    </ItemTemplate>
    <EditItemTemplate>
     <asp:TextBox ID="txtName" runat="server" Text='<%#Eval("name") %>'>
     </asp:TextBox>
      </EditItemTemplate>
      <FooterTemplate>
     <asp:TextBox ID="txtNewName" runat="server"></asp:TextBox>
     <asp:RequiredFieldValidator ID="RequiredFieldValidator1" runat="server" 
      ControlToValidate="txtNewName" SetFocusOnError="true" 
      ErrorMessage="*" ForeColor="Red"></asp:RequiredFieldValidator>
     </FooterTemplate>
     </asp:TemplateField>
     <asp:TemplateField>
     <ItemTemplate>
     <asp:LinkButton ID="lnkDelete" runat="server" Text="Delete" 
      CommandName="Delete"></asp:LinkButton>
     </ItemTemplate>
     <FooterTemplate>
     <asp:LinkButton ID="lnkInsert" runat="server" Text="Insert" 
       CommandName="Insert" ></asp:LinkButton>                    
     </FooterTemplate>
     </asp:TemplateField>
     </Columns>
    </asp:GridView>

CS:

protected void gv_RowCommand(object sender, GridViewCommandEventArgs e)
    {
        DataTable dt = new DataTable();

        switch (e.CommandName)
        {
            case "Insert":
                GridViewRow fRow = gv.FooterRow;
                dt.Columns.Add("id");
                dt.Columns.Add("name");
                dt = (DataTable)ViewState["students"];
                DataRow dr = dt.NewRow();
                dr["id"] = ((TextBox)fRow.FindControl("txtNewId")).Text;
                dr["name"] = ((TextBox)fRow.FindControl("txtNewName")).Text;
                dt.Rows.Add(dr);
                ViewState["students"] = dt;
                gv.DataSource = ViewState["students"];
                gv.DataBind();
                break;
        }
    }

The textboxes are txtNewId, txtNewName.

Answer 1

Do not use grid_Row command for insert. Use button click event

like this. It will solve your problem

protected void OnCmdInsertClick(object sender, EventArgs e)
{
    //Grid's footer row
    var footerRow = gv.FooterRow;
    if(footerRow !=null)
    {
        //get your textbox instances
        var txtNewId = (TextBox) footerRow.FindControl("txtNewId");
        var txtNewName = (TextBox) footerRow.FindControl("txtNewName");
        // Check for null
        if(txtNewId !=null && txtNewName !=null)
        {
            var dt = (DataTable)ViewState["students"];
            DataRow dr = dt.NewRow();
            dr["id"] =  txtNewId.Text;
            dr["name"] = txtNewName.Text;
            dt.Rows.Add(dr);                
            ViewState["students"] = dt;
            gv.DataSource = ViewState["students"];
            gv.DataBind();
        }
     }
}

Answer 2

In the button click event, use the following to get the actual GridViewRow of the footerL

protected void insertButton_Click(object sender, EventArgs e)
{
    // This is the crux - 
    GridViewRow row = (GridViewRow)((sender as Button).NamingContainer);
    // ...
    // then you can get your textboxes
    // Since we know it's an insert
    dt.Columns.Add("id");
    dt.Columns.Add("name");
    dt = (DataTable)Session["students"];
    DataRow dr = dt.NewRow();
    TextBox txtnewid = (TextBox) row.FindControl("txtNewId");
    TextBox txtnewName =  (TextBox) row.FindControl("txtNewName");
    dr["id"] =  txtnewid.Text;
    dr["name"] = txtnewName.Text ;
    dt.Rows.Add(dr);
    Session["students"] = dt;
    gv.DataSource = dt;
    gv.DataBind();
}

EDIT The reason viewstate didn't work is because the viewstate lasts only between postbacks. Sessions stay alive for the duration of the user's session. The default is 20 minutes of idle time.

You would normally use ViewState for persisting data between pages during a postback.

This doesn't address best practice, it's just what it is.

Answer 3

Please check whether you are binding the grid view correctly in the Page Load. What i mean to say is whether you are binding with in the if condidtion

       if(!IspostBack)
{

  BindGridView();
}

I hope this helps. Check it out..

Answer 4

protected void gv_RowCommand(object sender, GridViewCommandEventArgs e)
    {
        DataTable dt = new DataTable();

   if (e.CommandName.Equals("Insert"))
             {
                GridViewRow fRow = gv.FooterRow;
                dt.Columns.Add("id");
                dt.Columns.Add("name");
                dt = (DataTable)ViewState["students"];
                DataRow dr = dt.NewRow();
                TextBox txtnewid = (TextBox) fRow.FindControl("txtNewId");
                TextBox txtnewName =  (TextBox) fRow.FindControl("txtNewName");
                dr["id"] =  txtnewid.Text;
                dr["name"] = txtnewName.Text ;
                dt.Rows.Add(dr);
                ViewState["students"] = dt;
                gv.DataSource = ViewState["students"];
                gv.DataBind();
             }
    }

Answer 5

To bind the footer with data, use the below code

protected void gv_RowDataBound(object sender, GridViewRowEventArgs e)
{
    if (e.Row.RowType == DataControlRowType.Footer)
    {
         TextBox txtNewId = (TextBox)e.Row.FindControl("txtNewId");
         txtNewId.Text = "New 01";
    }
}

...and to retrieve value from the footer textbox,

TextBox txtNewId = (TextBox)gvGrid.FooterRow.FindControl("txtNewId");

Answer 6

Use This,

TextBox txtName = GridView1.FooterRow.FindControl("yourtextboxId") as TextBox;
string name = txtName.Text;

Or

GridViewRow row = ((GridView)sender).FooterRow;
TextBox txtName = (TextBox)row.FindControl("yourtextboxId");
if (txtName == null)
{
    return;
}
string name = txtName.Text;

Answer 7

I had the same problem and the best way to get the value is using:

((TextBox)<grid_name>.FooterRow.FindControl("<textBox_id>")).Text

I hope this helps.