C# shopping basket, trying to remove an item...

You see here's my problem, I've gotten to this point with a lot of help and some luck! I don't really fully understand how methods, functions, arguments and all that stuff works! It's taken me weeks of struggling and burning midnight oil just to get to where I have it at the moment, so if I've to go back and change the approach, I know I'll be into weeks of messing and trial by error because I don't really fully understand C# well enough or asp.net to just ditch one approach and pick up another one. I hope you see where I'm coming from with this, if I was a bit more fluent with it I'd probably give it a go but if I have to spend another 2 weeks at this the pc will be fired through the window and out onto the street!

Do you think it would be possible can use an ascx user control to get over this headwrecker problem I'm having with my Linkbutton??? I'm so frustrated with it because it looks perfect, and must be close to working based on where I have it at the moment.

If the Linkbutton has to be created in the Page_Load function, could I not just create the LinkButton there and call it somewhere else in my code???

Or put my LinkButton code into the ascx file and call it up when I need it in my code???

I've come up with a sort of a sh*ty solution but it's kind of getting me moving in the right direction again! Here goes...

Just in relation to the LinkButton event, I've moved this into the Page_Load function but I've also created a new DB connection for the Linkbutton with a new while loop that kind of (but doesn't exactly yet!) replicates the behaviour of the LinkButton when it was in the Button1_Click function...

So now my Page_Load which was empty except for the sessionID code, looks like this...

public void Page_Load(object sender, EventArgs e)
{
if (this.Session["dummy"] == null) { this.Session["dummy"] = 1; } lblSessionID.Text = this.Session.SessionID;

SqlConnection connUS = new SqlConnection("Data Source=My working connection string");
connUS.Open();

string selectSQLUS;

selectSQLUS = "SELECT * FROM used_equipment WHERE SessionID = '" + this.Session.SessionID + "'";
SqlCommand cmdUS = new SqlCommand(selectSQLUS, connUS);
cmdUS.CommandType = CommandType.Text;

SqlDataReader DataReader;
DataReader = cmdUS.ExecuteReader();

if (DataReader.HasRows)
{
//Label13.Text = "";

while (DataReader.Read())
{

LinkButton Delete_Btn = new LinkButton();
Delete_Btn.ID = string.Format(DataReader["Project_ID"].ToString());
Delete_Btn.Text = "Remove Item<BR><BR>";
Delete_Btn.CommandName = "DeleteMe";
Delete_Btn.PostBackUrl = "~/MainTestX.aspx";
Delete_Btn.Click += new EventHandler(Delete_Btn_Click);
Delete_Btn.CommandArgument = ("12");
Panel1.Controls.Add(Delete_Btn);
}
}
}


It needs to be tidyed up a bit but it's a fraction closer to where I was up until now with it.

Just wondering is there a way I can put a line of code into a function that forces the page to refresh or to run the Page_Load function again???

John_Mc wrote: »

Put the code that loads the cart into a function and call it from Page_Load and whenever the content of the cart is modified.

private void LoadCart()
{

}

But how do I "call it"??? I know these are basic questions, thanks for being patient with me on this! The way I survived this in uni was just horse everything into one function and somehow I managed to get away with it, so I never had to worry about working with different functions or arguments or methods or anything like that!

John_Mc wrote: »

Put the code that loads the cart into a function and call it from Page_Load and whenever the content of the cart is modified.

private void LoadCart()
{

}

Is it possible to do something like this:

PageLoad()

{
LoadCart();
DeleteItem();

Panel1.Controls.Add(LoadCart(Product_Label));
Panel1.Controls.Add(DeleteItem(Delete_LinkBtn));
}

If I wanted to bring together two separate controls from two different functions into my panel in the Page_Load function??? Assuming that I had one function called LoadCart to add items to my cart and another one called DeleteItem to delete an item??? I've tried it and am getting an error saying:

The name 'LoadCart_Product_Label' does not exist in the current context

What I mean is if I call up a function, are the controls that are within that function I'm calling up, not brought in within the scope of the function I'm calling this function from???

Well I've gone full circle with it now, I've managed to get the Delete_Btn Linkbutton working with the event handler, but now I have too many iterations of my LinkButton! ARGH!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

John_Mc wrote: »

What do you mean? Is it being called twice or are there duplicate items in the cart?

If it's the latter then clear the container of any controls before starting to add them.

If its the former use the IsPostback property prevent calling the LoadCart method in Page load.

E.g

if(!IsPostback)
{
LoadCart();
}

It's hard to explain what the problem is... I've tried clearing the container of controls but no matter what way I try to do it, I can't seem to get the solution I want...

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Web.Services;
using System.Collections.Specialized;
using AjaxControlToolkit;
using System.Data.SqlClient;
using System.Data.OleDb;
using System.Web.SessionState;
using System.Text;

public partial class _Default : System.Web.UI.Page
{
private bool CreateControls
{
get
{
return ViewState["CreateControls"] != null ? (bool)ViewState["CreateControls"] : false;
}
set
{
ViewState["CreateControls"] = value;
}
}


protected void Page_Load(object sender, EventArgs e)
{
if (this.Session["dummy"] == null) { this.Session["dummy"] = 1; } lblSessionID.Text = this.Session.SessionID;

if (CreateControls)
{
CreateTheControls();
}
}


protected void DropDownList3_SelectedIndexChanged(object sender, EventArgs e)
{
// Get selected values
string make = DropDownList1.SelectedItem.Text;
string model = DropDownList2.SelectedItem.Text;
string color = DropDownList3.SelectedItem.Text;

// Output result string based on which values are specified
if (string.IsNullOrEmpty(make))
{
Label1.Text = "Please Select an Engine Type.";
}
else if (string.IsNullOrEmpty(model))
{
Label1.Text = "Please select a model.";
}
else if (string.IsNullOrEmpty(color))
{
Label1.Text = "Please Select a Make.";
}
else
{
string dropdowna = DropDownList1.SelectedValue;
string dropdownb = DropDownList2.SelectedValue;
string dropdownc = DropDownList3.SelectedValue;


DateTime myDateTime1 = new DateTime();
myDateTime1 = new DateTime();
myDateTime1 = DateTime.Now;

string selectSQL;

//Connection for SELECT FROM "Vehicle data"
SqlConnection connz = new SqlConnection("Data Source....");
connz.Open();

selectSQL = "SELECT * FROM Vehicle_Data WHERE Vehicle_Make = '" + DropDownList1.SelectedItem.Value + "' AND Vehicle_Model = '" + DropDownList2.SelectedItem.Value + "' AND Engine_Type = '" + DropDownList3.SelectedItem.Value + "'";

SqlCommand cmdy = new SqlCommand(selectSQL, connz);
cmdy.CommandType = CommandType.Text;

SqlDataReader myDataReader;
myDataReader = cmdy.ExecuteReader();

Label1.Text = string.Format("Vehicle Information: {0} {1}.", make, model);
Label7.Text = string.Format("Engine Type: {0}.", color);

while (myDataReader.Read())

{
Label2.Text = string.Format("Your Purchase ID is: {0} ", myDataReader["Stock_Code"]);
Label12.Text = string.Format("Retail Price: €");
Label14.Text = string.Format("Product Info: ");
Label3.Text = string.Format("{0:F2}", myDataReader["Retail_Price"]);
Label4.Text = string.Format("{0} ", myDataReader["Product_Description"]);
Label5.Text = string.Format("{0} ", myDataReader["Component_Manufacturer"]);
Label15.Text = string.Format("Manufacturer: ");
Label6.Text = string.Format("Timestamp: {0} ", myDateTime1);

}

myDataReader.Close();
connz.Close();
}
}

[WebMethod]
[System.Web.Script.Services.ScriptMethod]
public static CascadingDropDownNameValue[] GetDropDownContentsPageMethod(string knownCategoryValues, string category)
{
return new CarsService().GetDropDownContents(knownCategoryValues, category);
}

public void Button1_Click(object sender, EventArgs e)
{
SqlConnection conn = new SqlConnection("Data Source....");
conn.Open();

if (this.Session["dummy"] == null) { this.Session["dummy"] = 1; } lblSessionID.Text = this.Session.SessionID;


string TransDateTime = DateTime.UtcNow.ToString("r");

string Delivery = string.Format("7.50");
string dropdown1 = DropDownList1.SelectedValue;
string dropdown2 = DropDownList2.SelectedValue;
string dropdown3 = DropDownList3.SelectedValue;
string Manufacturer = Label5.Text;
string Description = Label4.Text;
string Retail = Label3.Text;
string SessionID = lblSessionID.Text;


string sql = "insert into used_equipment (eq_type, eq_make, eq_model, SessionID, Retail_Price, Component_Manufacturer, Product_Description, Date_Time, Delivery_Cost)\n";
sql += "values(";

sql += "'" + dropdown1 + "',";
sql += "'" + dropdown2 + "',";
sql += "'" + dropdown3 + "',";
sql += "'" + SessionID + "',";
sql += "'" + Retail + "',";
sql += "'" + Manufacturer + "',";
sql += "'" + Description + "',";
sql += "'" + TransDateTime + "',";
sql += "'" + Delivery + "')";

SqlCommand cmd = new SqlCommand(sql, conn);
cmd.CommandType = CommandType.Text;
cmd.ExecuteNonQuery();
conn.Close();


////////////////////////////////////////////////////////////////

string selectSQLX;
string selectSUM;
string SumDelivery;

SqlConnection connT = new SqlConnection("Data Source....");
connT.Open();

SqlConnection connP = new SqlConnection("Data Source....");
connP.Open();

SqlConnection connX = new SqlConnection("Data Source....");
connX.Open();

selectSQLX = "SELECT * FROM used_equipment WHERE SessionID = '" + this.Session.SessionID + "'";
selectSUM = "SELECT SUM(Retail_Price) FROM used_equipment WHERE SessionID = '" + this.Session.SessionID + "'";
SumDelivery = "SELECT SUM(Delivery_Cost) FROM used_equipment WHERE SessionID = '" + this.Session.SessionID + "'";

SqlCommand cmdy = new SqlCommand(selectSQLX, connT);
cmdy.CommandType = CommandType.Text;

SqlCommand cmdu = new SqlCommand(selectSUM, connP);

SqlCommand cmdL = new SqlCommand(SumDelivery, connX);


SqlDataReader DataReader;
DataReader = cmdy.ExecuteReader();

Panel1.Controls.Clear();
if (DataReader.HasRows)
{
//Label13.Text = "";

while (DataReader.Read())
{

object obj1 = new object();
obj1 = string.Format(DataReader["eq_type"].ToString());

object obj2 = new object();
obj2 = string.Format(DataReader["eq_make"].ToString());

object obj3 = new object();
obj3 = string.Format(DataReader["eq_model"].ToString());

object obj4 = new object();
obj4 = string.Format(DataReader["Component_Manufacturer"].ToString());

object obj5 = new object();
obj5 = string.Format(DataReader["Product_Description"].ToString());

object obj6 = new object();
obj6 = string.Format(DataReader["Retail_Price"].ToString());

object obj7 = new object();
obj7 = string.Format(DataReader["Project_id"].ToString());

string newstring = string.Concat(obj1, " " + obj2, " " + obj3, "<br>" + obj4, " " + obj5, "<br>Retail Price: € " + obj6, "<BR>" + obj7, "<BR>");

Label Product_Label = new Label();
Product_Label.ID = string.Format(DataReader["Project_id"].ToString());
Product_Label.Text = newstring.ToString();


Panel1.Controls.Add(Product_Label);

CreateControls = true;
CreateTheControls();

}



decimal Cart = Convert.ToDecimal(cmdu.ExecuteScalar());
decimal Carry = Convert.ToDecimal(Delivery);
decimal Cart_Total = Cart + Carry;

Label Shopping_Cart = new Label();
Shopping_Cart.ID = "Cart";
Shopping_Cart.Text = string.Format("Order Total: € {0} ", (Cart));

Label Shipping_Label = new Label();
Shipping_Label.ID = "Shipping";
Shipping_Label.Text = string.Format("<BR>Shipping: € {0} ", (Carry));

Label Order_Total = new Label();
Order_Total.ID = "Order_Tot";
Order_Total.Text = string.Format("<BR>Invoice Total: € {0} ", (Cart_Total));

Panel1.Controls.Add(Shopping_Cart);
Panel1.Controls.Add(Shipping_Label);
Panel1.Controls.Add(Order_Total);

}

DataReader.Close();
connT.Close();
connP.Close();
}


protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
{

}

protected void DropDownList2_SelectedIndexChanged(object sender, EventArgs e)
{

}

protected void Button2_Click(object sender, EventArgs e)
{

}

protected void Delete_Btn_Click(object sender, EventArgs e)
{
Label Delete_Text = new Label();
Delete_Text.ID = string.Format("12");
Delete_Text.Text = string.Format("Item has been deleted!");
Panel1.Controls.Clear();
Panel1.Controls.Add(Delete_Text);

}

public void CreateTheControls()
{

SqlConnection connUS = new SqlConnection("Data Source....");
connUS.Open();

string selectSQLXUS;

selectSQLXUS = "SELECT * FROM used_equipment WHERE SessionID = '" + this.Session.SessionID + "'";

SqlCommand cmdUS = new SqlCommand(selectSQLXUS, connUS);
cmdUS.CommandType = CommandType.Text;
SqlDataReader MyDataReader;
MyDataReader = cmdUS.ExecuteReader();

if (MyDataReader.HasRows)
{
////////////////////////////////////////////////////////////

while (MyDataReader.Read())
{

LinkButton Delete_Btn = new LinkButton();
Delete_Btn.ID = string.Format(MyDataReader["Project_id"].ToString());
Delete_Btn.Text = "Remove Item<BR><BR>";
Delete_Btn.CommandName = "DeleteMe";
//Delete_Btn.PostBackUrl = "~/MainTestX.aspx";
Delete_Btn.OnClientClick = "";
Delete_Btn.CommandArgument = string.Format("13");
Delete_Btn.Click += new EventHandler(Delete_Btn_Click);
Panel1.Controls.Add(Delete_Btn);

}
}

}

}

The code in bold seems to be the problem. If I add in a clear container where I've inserted the comment line in bold, I end up clearing out the whole container, including the grey text that is my Product_Label string.

You can see the problem more clearly in the attached image... The linkButton ID's for both buttons are $479 and $480 when I hover the mouse over them...

I had this problem before with a label and I resolved it by appending two pieces of into into the one label instead of using two labels and it seems to be the same thing going on here...

I'm wondering is there any way I could do something like this that I think would resolve the issue...

Panel1.Controls.Add(Product_Label);
Panel1.Controls.Add(CreateTheControls);
CreateControls = true;
//CreateTheControls();



I'm getting an error when I do that as I can't just use a function like that with a control but if I could do something like this, I think I'd basically be appending the container as opposed to what I'm doing at the moment which is a bit messy...

I've did a bit of Googling and I found this which looks like it sets me up with a DataTable and it's compiling for me no bother...

private DataTable CreateDataTable()
{
DataTable myDataTable = new DataTable();

DataColumn myDataColumn;

myDataColumn = new DataColumn();
myDataColumn.DataType = Type.GetType("System.String");
myDataColumn.ColumnName = "id";
myDataTable.Columns.Add(myDataColumn);

myDataColumn = new DataColumn();
myDataColumn.DataType = Type.GetType("System.String");
myDataColumn.ColumnName = "username";
myDataTable.Columns.Add(myDataColumn);

myDataColumn = new DataColumn();
myDataColumn.DataType = Type.GetType("System.String");
myDataColumn.ColumnName = "firstname";
myDataTable.Columns.Add(myDataColumn);

myDataColumn = new DataColumn();
myDataColumn.DataType = Type.GetType("System.String");
myDataColumn.ColumnName = "lastname";
myDataTable.Columns.Add(myDataColumn);

return myDataTable;
}

So I just adapt the columns to match up with my SQLDB? Then I just have to populate my DataTable, do I use a datareader to do this???

Ginger wrote: »

I have a sample project that does something similar and I will upload it here for you.

Its a pure skeleton but shows a repeater being databound for example and also shows it with Common objects, DataLayer, Business and a handy little trick of filling objects if you have named the properties the same in the database

Pm for password

Jasus that looks seriously complicated!

Ginger wrote: »

Right ok, you are probably running on IIS, I run mine on Cassini (the dev web server)

Right first question running on IIS? You need to configure the virtual folder as an application

If its not that

Second question, are you running in a folder and and is there a web.config above that folder... IE is there 2 web.configs in the same path

I just created a new website and copied your files into it and that seems to have sorted out the problem there. Even just seeing this working is enough to make me want to go out for a few pints to celebrate!!!

I have to pop out for an hour or two for a meeting but I'll be back later pulling that solution you gave me apart! Thanks again so much to the both of you... Beers on me in Dublin!

Ginger wrote: »

Just realised I didnt supply a database if you are using SQL Server 2008 I can send you the files, otherwise I will create an SQL script for you with all the procs and logins etc

N

I'm using MS SQL Server 2005. I think I can knock that bit of it together though....

What I'm trying to do now is pull asunder the code I have that adds stuff to my cart (DB up until now), and get it to add items into this new datatable that you gave me...

I swear when I get this finished, I'll never defile a computer with my presence again! :D:D

Ginger wrote: »

Oki doki

I created a shopping cart demo for you.

Consists of 2 pages. Catalog and ShoppingCart

Catalog displays all the products and allows you to add them to your cart.

ShoppingCart shows the contents of your cart and alls you to remove them from the cart.

Its extremely basic, I wrote it in about 2 hours over brekkie so there is feck all error handling in it ie none.

Targetted for .NET 2.0 and built using VS 2008. You can import the projects one by one into VS2005.

Just create a blank solution and and the projects in the following order

Common
DataAccess
Business
ShoppingCartDemo (ASPX Site)

You will possibly need to readd the references

DataAccess references Common
Business references Common and DataAccess
ShoppingCartDemo references Business and Common

Code is commented somewhat to make it easier to understand.

DB Script to recreate the database and procs included. Add some data.

Now you will need to adjust your connection string.

HTH

Just after seeing this... Wakey wakey here!