Unable to get text field from text field in itemtemplate

Question

The quantity (the quantity added to the database) in the text field is loaded by the Eval () method from the basket basket table. What I want to achieve is that when I change the quantity manually and click update, the quantity for this record will be updated and then the grid will be reloaded. It seems I can not get the value of this text field in the code.

I know the FindControl () method, which is used to get the value from the controls in the itemtemplate, but I don’t know how to use it here.

Awakened below, but always gets a nullReferenceException

TextBox txt = (TextBox)GridView2.FindControl("txtQuantityWanted"); int _quantity = Convert.ToInt16(txt.Text); 

Note: there is a button, but does nothing.

 <ItemTemplate> <asp:TextBox runat="server" ID="txtQuantityWanted" Text='<%# Eval("quantityWanted") %>' ></asp:TextBox> <asp:LinkButton ID="LinkButton11" runat="server" CommandName="update" CommandArgument='<%# Eval("coffeeName") + ";" + Eval("datetimeAdded") %>' >Update</asp:LinkButton> <asp:Button ID="Button21" runat="server" Text="Button" CommandName="edit" /> </ItemTemplate> <asp:TemplateField HeaderText="Total [£]"> <ItemTemplate> <asp:Label id="lblItemTotal" runat="server" Text='<%# String.Format("{0:C}", Convert.ToInt32(Eval("quantityWanted"))* Convert.ToDouble(Eval("price"))) %>' ></asp:Label> <asp:LinkButton ID="LinkButton1" runat="server" CommandName="remove" CommandArgument='<%# Eval("coffeeName") + ";" + Eval("datetimeAdded") %>' >Remove</asp:LinkButton> </ItemTemplate> </asp:TemplateField> 

C # code:

 protected void GridView2_RowCommand(object sender, GridViewCommandEventArgs e) { // ..... else if (e.CommandName == "update") { string params = Convert.ToString(e.CommandArgument); string[] arg = new string[2]; arg = params.Split(';'); name = Convert.ToString(arg[0]); datetimeAdded = Convert.ToString(arg[1]); const string strConn = @"Data Source=.\SQLEXPRESS;AttachDbFilename=L:\ASP.NET\Exercise1\Exercise1\Exercise1\App_Data\ASPNETDB.MDF;Integrated Security=True;Connect Timeout=30;User Instance=True"; DataSet ds = new DataSet("Employees"); SqlConnection connection = new SqlConnection(strConn); // Here I need value from textbox to replace 11 SqlCommand abc = new SqlCommand("UPDATE Basket SET quantityWanted = 11 WHERE coffeeName LIKE '%" + name + "%' AND datetimeAdded LIKE '" + datetimeAdded + "' ", connection); connection.Open(); int ii = abc.ExecuteNonQuery(); connection.Close(); } } 

Answer 1

Use the GridView.Rows collection to find the control. You can pass the row index in the row index index.

 TextBox txt = (TextBox)GridView2.Rows[0].FindControl("txtQuantityWanted"); 

Answer 2

You should also pass the row index, your code will look like this

 TextBox txt = (TextBox)GridView2.Rows[0].FindControl("txtQuantityWanted"); 

I hope this works for you.

Answer 3

  Control ctrl = e.CommandSource as Control; if (ctrl != null) { GridViewRow gvRow = ctrl.Parent.NamingContainer as GridViewRow; TextBox txt= (TextBox)gvRow.FindControl("txtQuantityWanted"); }