ObjectDatasource passing parameters - asp.net-3.5

Question

I want to Insert data from textboxes using ObjectDatasource. The ObjectDataSource is bound to a gridview but displays certain computed columns only. The Textboxes are used to input all the basic inputs.
ObjectDatasource Delete & Select commands (Link buttons on gridview) are working. However I am having trouble with Insert command. I am not able to figure out how to pass the data from the textboxes as parameters to the ObjectDataSource Insert
EDIT: With the code below, a record is getting inserted. Parameters are getting passed. odssMain.Insert() gives the Error: "Object reference not set to an instance of an object".
EDIT: WHY AM I GETTING THIS ERROR?
Also the ObjectDataSource has been acting weird. After an error, I have to reconfigure the Insert Method again on the ODS Wizard as the method will be blank.
ASP.NET 3.5 & SQL 2008, VS 2008.
Here's my code:
<asp:ObjectDataSource ID="odsMain" runat="server"
SelectMethod="SelectMain" DeleteMethod="DeleteMain"
InsertMethod="InsertMain" UpdateMethod="UpdateMain"
OldValuesParameterFormatString="original_{0}" TypeName="MainDB" >
.......
<InsertParameters>
<asp:Parameter Name="Quantity" Type="Int32" />
</InsertParameters>
DAL FILE:
[DataObjectMethod(DataObjectMethodType.Insert)]
public static int InsertMain(int Quantity)/
{
SqlConnection con = new SqlConnection(GetConnectionString());
string strQuery = "INSERT INTO t_Main (Quantity) VALUES (#Quantity)";
SqlCommand cmd = new SqlCommand(strQuery, con);
cmd.Parameters.AddWithValue("#Quantity", Quantity);
con.Open();
int i = cmd.ExecuteNonQuery();
con.Close();
return i;
}
CODE BEHIND FILE:
protected void btnSaveAnalysis_Click(object sender, EventArgs e)
{
odsMain.InsertParameters.Clear();
//Store parameters with values to the collection
odsMain.InsertParameters.Add(new Parameter ("Quantity", TypeCode.Int32, iQuantity.ToString()));
//Diferent ways that I tried. Still not working
//odsMain.InsertParameters.Add("Quantity", iQuantity.ToString());
//odsMain.InsertParameters["Quantity"].DefaultValue = iQuantity.ToString();
odsMain.Insert();
}

Answer 1

you could try like this....
ObjectDataSource for InsertParameter looks like below one
<InsertParameters>
<asp:Parameter Name="FirstName" />
<asp:Parameter Name="MiddleName" />
<asp:Parameter Name="LastName" />
<asp:Parameter Name="Desgination" />
<asp:Parameter Name="Address" />
<asp:Parameter Name="City" />
<asp:Parameter Name="State" />
<asp:Parameter Name="Country" />
</InsertParameters>
I will also pass InsertMethod property of ObjectDataSource,which will have an InsertCustomer method.
InsertCustomer method looks like below one :-
public void InsertCustomer(string FirstName, string MiddleName,string LastName, string Desgination, string Address, string City, string State, string Country)
{
SqlConnection con = new SqlConnection(conStr);
SqlCommand cmd = new SqlCommand("InsertCustomer", con);
cmd.CommandType = CommandType.StoredProcedure;
//this check is necessary, when u don't pass any value as it will pass as [default] and will give error
if (string.IsNullOrEmpty(FirstName))
FirstName = string.Empty;
if (string.IsNullOrEmpty(LastName))
LastName = string.Empty;
if (string.IsNullOrEmpty(MiddleName))
MiddleName = string.Empty;
if (string.IsNullOrEmpty(Desgination))
Desgination = string.Empty;
if (string.IsNullOrEmpty(Address))
Address = string.Empty;
if (string.IsNullOrEmpty(City))
City = string.Empty;
if (string.IsNullOrEmpty(State))
State = string.Empty;
if (string.IsNullOrEmpty(Country))
Country = string.Empty;
cmd.Parameters.AddWithValue("#IV_FirstName", FirstName);
cmd.Parameters.AddWithValue("#IV_LastName", LastName);
cmd.Parameters.AddWithValue("#IV_MiddleName", MiddleName);
cmd.Parameters.AddWithValue("#IV_Desgination", Desgination);
cmd.Parameters.AddWithValue("#IV_Address", Address);
cmd.Parameters.AddWithValue("#IV_City", City);
cmd.Parameters.AddWithValue("#IV_State", State);
cmd.Parameters.AddWithValue("#IV_Country", Country);
using (con)
{
con.Open();
cmd.ExecuteNonQuery();
}
}
Button Save for inserting record.
//Insert record Save Button
protected void btnSave_Click(object sender, EventArgs e)
{
Customer.InsertParameters["FirstName"].DefaultValue = GetGridTextBoxValue("txtFirstName");
Customer.InsertParameters["MiddleName"].DefaultValue = GetGridTextBoxValue("txtMiddleName");
Customer.InsertParameters["LastName"].DefaultValue = GetGridTextBoxValue("txtLastName");
Customer.InsertParameters["Desgination"].DefaultValue= GetGridTextBoxValue("txtDesgination");
Customer.InsertParameters["Address"].DefaultValue = GetGridTextBoxValue("txtAddress");
Customer.InsertParameters["City"].DefaultValue = GetGridTextBoxValue("txtCity");
Customer.InsertParameters["State"].DefaultValue = GetGridTextBoxValue("txtState");
Customer.InsertParameters["Country"].DefaultValue = GetGridTextBoxValue("txtCountry");
Customer.Insert();
}
GetGridTextBoxValue function will get TextBox text value from footer row of respective column.
//Get TextBox value of GridView Footer Row
public string GetGridTextBoxValue(string txtID)
{
try
{
TextBox txt = (TextBox)gvCustomer.FooterRow.FindControl(txtID); // here you can place any text box value on your design page
return txt.Text;
}
catch (Exception ex)
{
return string.Empty;
throw ex;
}
}
and the results image is like this ...