updating a shopping cart : The Official Microsoft ASP.NET Forums

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bouncyger

Member

8 Points

updating a shopping cart

May 03, 2012 09:42 PM|LINK

i have 2 buttons in a shopping cart which is a datagrid...I have one column called price. I also have 2 buttons on each row od the datagrid. I want to be able to click on one button and that will add the value of the item in that row to the total. I also want to click on the other button and that would decrease the total.

Total is in a label below the datagrid.

Any help appreciated.

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karthicks

All-Star

31334 Points

5414 Posts

Re: updating a shopping cart

May 04, 2012 06:47 AM|LINK

hi, here i have given two examples, whichever suits for you you can use

<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="false"
		onrowcommand="GridView1_RowCommand">
		<Columns>
			<asp:BoundField HeaderText="Price" DataField="Price" />
			<asp:ButtonField HeaderText="Add" ButtonType="Button" Text="Add" CommandName="Add" />
			<asp:ButtonField HeaderText="Remove" ButtonType="Button" Text="Remove" CommandName="Remove" />
		</Columns>
	</asp:GridView>
	<asp:Label ID="lblTotal" runat="server" Text="0"></asp:Label>
	<asp:GridView ID="GridView2" runat="server" AutoGenerateColumns="false"
		onrowcommand="GridView2_RowCommand">
		<Columns>
			<asp:TemplateField HeaderText="Price">
				<ItemTemplate>
					<asp:Label ID="lblPrice" runat="server" Text='<%# Eval("Price") %>'></asp:Label>
				</ItemTemplate>
			</asp:TemplateField>
			<asp:TemplateField HeaderText="Add">
				<ItemTemplate>
					<asp:Button ID="btnAdd" runat="server" Text="Add" CommandName="Add" CommandArgument='<%# Container.DataItemIndex %>' />
				</ItemTemplate>
			</asp:TemplateField>
			<asp:TemplateField HeaderText="Remove">
				<ItemTemplate>
					<asp:Button ID="btnRemove" runat="server" Text="Remove" CommandName="Remove" CommandArgument='<%# Container.DataItemIndex %>' />
				</ItemTemplate>
			</asp:TemplateField>
		</Columns>
	</asp:GridView>
	<asp:Label ID="lblTotal2" runat="server" Text="0"></asp:Label>

	protected void Page_Load(object sender, EventArgs e)
	{
		if (!Page.IsPostBack)
			this.BindGrid();
	}

	private void BindGrid()
	{
		DataTable dt = new DataTable();
		dt.Columns.Add("Price");
		dt.Rows.Add(new Object[] { "3.19" });
		dt.Rows.Add(new Object[] { "3.56" });
		dt.Rows.Add(new Object[] { "4.25" });
		dt.Rows.Add(new Object[] { "4.89" });

		this.GridView1.DataSource = dt;
		this.GridView1.DataBind();

		this.GridView2.DataSource = dt;
		this.GridView2.DataBind();
	}
	protected void GridView1_RowCommand(object sender, GridViewCommandEventArgs e)
	{
		int index = Convert.ToInt32(e.CommandArgument);
		switch (e.CommandName)
		{
			case "Add":
				this.lblTotal.Text = (Convert.ToDouble(this.lblTotal.Text) + Convert.ToDouble(this.GridView1.Rows[index].Cells[0].Text)).ToString();
				break;
			case "Remove":
				this.lblTotal.Text = (Convert.ToDouble(this.lblTotal.Text) - Convert.ToDouble(this.GridView1.Rows[index].Cells[0].Text)).ToString();
				break;
		}
	}

	protected void GridView2_RowCommand(object sender, GridViewCommandEventArgs e)
	{
		int index = Convert.ToInt32(e.CommandArgument);
		switch (e.CommandName)
		{
			case "Add":
				this.lblTotal2.Text = (Convert.ToDouble(this.lblTotal2.Text) + Convert.ToDouble((this.GridView2.Rows[index].FindControl("lblPrice") as Label).Text)).ToString();
				break;
			case "Remove":
				this.lblTotal2.Text = (Convert.ToDouble(this.lblTotal2.Text) - Convert.ToDouble((this.GridView2.Rows[index].FindControl("lblPrice") as Label).Text)).ToString();
				break;
		}
	}

Thanks,
Karthick S

Edited by bouncyger on May 04, 2012 09:43 AM
Edited by bouncyger on May 04, 2012 10:56 AM

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bouncyger

Member

8 Points

68 Posts

Re: updating a shopping cart

May 04, 2012 08:56 AM|LINK

Here is my code with what i thought i had to add from yours getting a compilation error

BC30205: End of statement expected.

Source Error:

Line 35:     
Line 36: 	
Line 37: protected void gdvproducts_RowCommand(object sender, GridViewCommandEventArgs e) Line 38:         {
Line 39:                 int index = Convert.ToInt32(e.CommandArgument);

<%@ Page Language="VB" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs)

	 
        
        
        Dim strDatabaseNameAndLocation As String
        strDatabaseNameAndLocation = Server.MapPath("shop.mdb")
        Dim strSQLCommand As String
        strSQLCommand = "SELECT Product.* FROM Product ORDER BY Product.productID ASC;"
        Dim objOleDbConnection As System.Data.OleDb.OleDbConnection
        objOleDbConnection = New System.Data.OleDb.OleDbConnection("Provider=Microsoft.Jet.Oledb.4.0; Data Source=" & strDatabaseNameAndLocation)
        objOleDbConnection .Open()
        Dim objOleDbCommand As System.Data.OleDb.OleDbCommand
        objOleDbCommand = New System.Data.OleDb.OleDbCommand(strSQLCommand, objOleDbConnection)
        Dim objOleDbDataReader As System.Data.OleDb.OleDbDataReader
        objOleDbDataReader = objOleDbCommand.ExecuteReader()
        gdvproducts.DataSource = objOleDbDataReader 
        Dim datDataTable As System.Data.DataTable
        datDataTable = New System.Data.DataTable()
        datDataTable.Load(objOleDbDataReader)
        gdvproducts.DataSource = datDataTable
        gdvproducts.DataBind()
        objOleDbConnection .Close()

	Dim inttotal As string
	inttotal = 0
	lbltotal.Text = inttotal

	End Sub
    
	
	   protected void gdvproducts_RowCommand(object sender, GridViewCommandEventArgs e)
        {
                int index = Convert.ToInt32(e.CommandArgument);
                switch (e.CommandName)
                {
                        case "Add":
                                this.lblTotal.Text = (Convert.ToDouble(this.lblTotal.Text) + Convert.ToDouble(this.gdvproducts.Rows[index].Cells[2].Text)).ToString();
                                break;
                        case "Remove":
                                this.lblTotal.Text = (Convert.ToDouble(this.lblTotal.Text) - Convert.ToDouble(this.gdvproducts.Rows[index].Cells[2].Text)).ToString();
                                break;
                }
        }

</script>
<html xmlns="http://www.w3.org/1999/xhtml">

<head runat="server">
<title>Supplies Shop</title>
</head>

<body>
<asp:Image ID="imglogo" ImageUrl = "images/shoplogo.jpg" runat="server"></asp:Image>

<form id="webform" runat="server">
    <div>
        <asp:GridView ID="gdvproducts" runat="server" AutoGenerateColumns="False" 
            DataKeyNames="productID" onrowcommand="gdvproducts_RowCommand" >
            <Columns>
                <asp:BoundField DataField="productID" HeaderText="Product ID" 
                    InsertVisible="False" ReadOnly="True" SortExpression="productID" />
                <asp:BoundField DataField="productName" HeaderText="Name" 
                    SortExpression="productName" />
                <asp:BoundField DataField="productPrice" HeaderText="Price" 
                    SortExpression="productPrice" />
		<asp:TemplateField HeaderText="Add">
		<ItemTemplate>
                    <asp:Button id="btnAdd" runat="server" postbackurl="cart.aspx" text="add" />
                </ItemTemplate>
             	</asp:TemplateField>
<asp:TemplateField HeaderText="Remove">
		<ItemTemplate>
                    <asp:Button id="btnRemove" runat="server" postbackurl="cart.aspx" text="remove" />
                </ItemTemplate>
             	</asp:TemplateField>
            </Columns>
        </asp:GridView>
	
	<p>
	<asp:Label ID="lbltotal" runat="server"></asp:Label></p>
    </div>
</form>

</body>

</html>

Edited by bouncyger on May 04, 2012 09:43 AM
Edited by bouncyger on May 04, 2012 10:56 AM

Reply

karthicks

All-Star

31334 Points

5414 Posts

Re: updating a shopping cart

May 04, 2012 09:13 AM|LINK

hi, the code i have posted earlier is in C#, the below code for vb.net so refer below code

Protected Sub Page_Load(sender As Object, e As EventArgs)
	If Not Page.IsPostBack Then
		Me.BindGrid()
	End If
End Sub

Private Sub BindGrid()
	Dim dt As New DataTable()
	dt.Columns.Add("Price")
	dt.Rows.Add(New [Object]() {"3.19"})
	dt.Rows.Add(New [Object]() {"3.56"})
	dt.Rows.Add(New [Object]() {"4.25"})
	dt.Rows.Add(New [Object]() {"4.89"})

	Me.GridView1.DataSource = dt
	Me.GridView1.DataBind()

	Me.GridView2.DataSource = dt
	Me.GridView2.DataBind()
End Sub
Protected Sub GridView1_RowCommand(sender As Object, e As GridViewCommandEventArgs)
	Dim index As Integer = Convert.ToInt32(e.CommandArgument)
	Select Case e.CommandName
		Case "Add"
			Me.lblTotal.Text = (Convert.ToDouble(Me.lblTotal.Text) + Convert.ToDouble(Me.GridView1.Rows(index).Cells(0).Text)).ToString()
			Exit Select
		Case "Remove"
			Me.lblTotal.Text = (Convert.ToDouble(Me.lblTotal.Text) - Convert.ToDouble(Me.GridView1.Rows(index).Cells(0).Text)).ToString()
			Exit Select
	End Select
End Sub

Protected Sub GridView2_RowCommand(sender As Object, e As GridViewCommandEventArgs)
	Dim index As Integer = Convert.ToInt32(e.CommandArgument)
	Select Case e.CommandName
		Case "Add"
			Me.lblTotal2.Text = (Convert.ToDouble(Me.lblTotal2.Text) + Convert.ToDouble(TryCast(Me.GridView2.Rows(index).FindControl("lblPrice"), Label).Text)).ToString()
			Exit Select
		Case "Remove"
			Me.lblTotal2.Text = (Convert.ToDouble(Me.lblTotal2.Text) - Convert.ToDouble(TryCast(Me.GridView2.Rows(index).FindControl("lblPrice"), Label).Text)).ToString()
			Exit Select
	End Select
End Sub

Refer : http://www.developerfusion.com/tools/convert/csharp-to-vb/

Mark both my replies as answered one

Thanks,
Karthick S

Marked as answer by Catherine Shan - MSFT on May 10, 2012 02:02 AM

Reply

bouncyger

Member

8 Points

68 Posts

Re: updating a shopping cart

May 04, 2012 09:46 AM|LINK

Hi

Thanks for your replies and I feel really stupid for not realising that was c#, it now compiles but nothing appearing in the total label when i press the add button!!  Code below

Any suggestions?

<%@ Page Language="VB" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs)

	 
        
        
        Dim strDatabaseNameAndLocation As String
        strDatabaseNameAndLocation = Server.MapPath("shop.mdb")
        Dim strSQLCommand As String
        strSQLCommand = "SELECT Product.* FROM Product ORDER BY Product.productID ASC;"
        Dim objOleDbConnection As System.Data.OleDb.OleDbConnection
        objOleDbConnection = New System.Data.OleDb.OleDbConnection("Provider=Microsoft.Jet.Oledb.4.0; Data Source=" & strDatabaseNameAndLocation)
        objOleDbConnection .Open()
        Dim objOleDbCommand As System.Data.OleDb.OleDbCommand
        objOleDbCommand = New System.Data.OleDb.OleDbCommand(strSQLCommand, objOleDbConnection)
        Dim objOleDbDataReader As System.Data.OleDb.OleDbDataReader
        objOleDbDataReader = objOleDbCommand.ExecuteReader()
        gdvproducts.DataSource = objOleDbDataReader
        Dim datDataTable As System.Data.DataTable
        datDataTable = New System.Data.DataTable()
        datDataTable.Load(objOleDbDataReader)
        gdvproducts.DataSource = datDataTable
        gdvproducts.DataBind()
        objOleDbConnection .Close()

	'Dim inttotal As string
	'inttotal = 0
	'lblTotal.Text = inttotal

	End Sub
    
	Protected Sub gdvproducts_RowCommand(sender As Object, e As GridViewCommandEventArgs)
        Dim index As Integer = Convert.ToInt32(e.CommandArgument)
        Select Case e.CommandName
                Case "Add"
                        Me.lblTotal.Text = (Convert.ToDouble(Me.lblTotal.Text) + Convert.ToDouble(Me.gdvproducts.Rows(index).Cells(2).Text)).ToString()
                        Exit Select
                Case "Remove"
                        Me.lblTotal.Text = (Convert.ToDouble(Me.lblTotal.Text) - Convert.ToDouble(Me.gdvproducts.Rows(index).Cells(2).Text)).ToString()
                        Exit Select
        End Select
End Sub

</script>
<html xmlns="http://www.w3.org/1999/xhtml">

<head runat="server">
<title>Supplies Shop</title>
</head>

<body>
<asp:Image ID="imglogo" ImageUrl = "images/shoplogo.jpg" runat="server"></asp:Image>

<form id="webform" runat="server">
    <div>
        <asp:GridView ID="gdvproducts" runat="server" AutoGenerateColumns="False"
            DataKeyNames="productID" onrowcommand="gdvproducts_RowCommand" >
            <Columns>
                <asp:BoundField DataField="productID" HeaderText="Product ID"
                    InsertVisible="False" ReadOnly="True" SortExpression="productID" />
                <asp:BoundField DataField="productName" HeaderText="Name"
                    SortExpression="productName" />
                <asp:BoundField DataField="productPrice" HeaderText="Price"
                    SortExpression="productPrice" />
		<asp:TemplateField HeaderText="Add">
		<ItemTemplate>
                    <asp:Button id="btnAdd" runat="server" postbackurl="cart.aspx" text="add" />
                </ItemTemplate>
             	</asp:TemplateField>
<asp:TemplateField HeaderText="Remove">
		<ItemTemplate>
                    <asp:Button id="btnRemove" runat="server" postbackurl="cart.aspx" text="remove" />
                </ItemTemplate>
             	</asp:TemplateField>
            </Columns>
        </asp:GridView>
	
	<p>
	<asp:Label ID="lblTotal" runat="server" Text = "0"></asp:Label></p>
    </div>
</form>

</body>

</html>

Reply

karthicks

All-Star

31334 Points

5414 Posts

Re: updating a shopping cart

May 05, 2012 04:07 AM|LINK

hi, first remove the postbackurl="cart.aspx" from both the buttons, and you did not give CommandName and CommandArgument in Add & Remove buttons , cleraly go thru my code and use

<asp:TemplateField HeaderText="Add">
<ItemTemplate>
<asp:Button ID="btnAdd" runat="server" Text="Add" CommandName="Add" CommandArgument='<%# Container.DataItemIndex %>' />
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Remove">
<ItemTemplate>
<asp:Button ID="btnRemove" runat="server" Text="Remove" CommandName="Remove" CommandArgument='<%# Container.DataItemIndex %>' />
</ItemTemplate>
</asp:TemplateField>

also you should not blindly bind your grid on every postback, so encapsulate Page_Load code with

If Not Page.IsPostBack Then

' code to bind grid

End If

Mark all my replies as answered one

Thanks,
Karthick S

Marked as answer by Catherine Shan - MSFT on May 10, 2012 02:02 AM

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bouncyger

updating a shopping cart

karthicks

Re: updating a shopping cart

bouncyger

Re: updating a shopping cart

karthicks

Re: updating a shopping cart

bouncyger

Re: updating a shopping cart

karthicks

Re: updating a shopping cart

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