Microsoft ASP .NET Professional Projects - Premier Press

auom.text = ""

hidePanel()

End Sub

Note that we are passing a NULL code_value to the procedure. This fires an insert statement. This SQL query string is passed on to the function RunSQL, which does the actual work of executing the SQL statement.

Delete Mode

The Delete mode is activated when the user clicks on the delete link. I have created a delete ButtonColumn as follows:

<asp:ButtonColumn Text="Delete" CommandName="Delete" HeaderText="Delete"/> I have associated an OnDeleteCommand with this button as follows:

<asp:DataGrid id="Grid1" runat="server"

---------------------------------------------------------------

OnDeleteCommand = "Grid1_delete"

--------------------------------------------------------------- >

In the Grid1_Delete event, I simply build a delete statement and pass it on to the function RunSQL, which applies the query against the database.

Sub Grid1_delete

Sub Grid1_delete(sender As Object, e As DataGridCommandEventArgs)

Dim code_value As string = Grid1.DataKeys.Item(E.Item.ItemIndex).ToString

Dim sql As string

sql = "Delete from stock_master where code_value = " + cstr(code_value)

RunSql(sql)

End Sub

The RunSql Function

This is a generic function, which executes a SQL Action statement against the database. The SQL query statement is passed to it as a parameter. The Grid1_update Sub, the Add_click Sub, and the Grid1_delete Sub call this function to update, add, or delete a record. This function calls the RunSql function of the web service and passes it the connection string, as well as the SQL action query/procedure call. If the procedure/query was executed successfully, the string Success is returned from the function. Otherwise, the appropriate error string is returned, which is displayed in the browser.

Sub RunSql

Sub RunSql(vSQL as string)

Dim ConnStr As String

Dim SQL As String

ConnStr = "Provider=SQLOLEDB; Data Source=(local); "

ConnStr = ConnStr+" Initial Catalog=ASPNET;User ID=sa;"

Dim t As New NameSpaceHersh.SQLService

Dim s As string

s = t.RunSQL(ConnStr,vSQL)

Grid1.EditItemIndex = -1

if s <> "Success" then

Message.Text = s

Message.Style("color") = "red"

End if

response.write (vsql)

Rebind

End Sub

Sorting

The DataGrid enables you to sort the columns by clicking on a link below the columns. Setting the AllowSorting property to true triggers this built-in mechanism, as follows:

<asp:DataGrid id="Grid1" runat="server"

AllowSorting="true"

OnSortCommand="MyDataGrid_Sort">

When this property is set to true, the DataGrid renders the column captions with a linkbutton. If you now click on a column, the OnSortEvent is fired. This event contains the following code:

Sub MyDataGrid_Sort(sender As Object, e As DataGridSortCommandEventArgs)

SortField = e.SortField

ReBind

End Sub

The SortField variable is a Public (string) variable, which holds the name of the column, and by which the DataGrid is to be sorted. It is initially set to the code_display column in the page_load event as follows:

Sub Page_Load(Source As Object, E As EventArgs)

If NOT (isPostBack)

If SortField = "" Then

SortField = "code_display"

End If

ReBind

End If

End Sub

You need to set the SortExpression attribute in the column templates. For example, for the rate column to participate in sorting, you have to set the template as follows:

<asp:TemplateColumn HeaderText="Rate" SortExpression ="rate" >

</asp:TemplateColumn>

Each time the user clicks on a "sortable" column, the MyDataGrid_Sort Sub is fired. The SortField variable again gets set in this method.

Sub MyDataGrid_Sort(sender As Object, e As DataGridSortCommandEventArgs)

SortField = e.SortExpression

ReBind

End Sub

The ReBind function uses the SortExpression attribute to sort the DataView (which in turn binds the DataGrid), and refreshes the DataGrid to reflect the rows sorted by the new sort field, as follows:

Sub ReBind()

Dim ConnStr As String

Dim SQL As String

ConnStr = "Provider=SQLOLEDB; Data Source=(local); "

ConnStr = ConnStr+" Initial Catalog=ASPNET;User ID=sa;"

Dim t As New NameSpaceHersh.SQLService

Dim ds As DataSet

' Bind Grid

SQL = "Select * from stock_master"

ds = t.Populate(ConnStr, SQL)

Dim dv2 As DataView

dv2 = ds.Tables("vTable").DefaultView

dv2.Sort = SortField

Grid1.DataSource= dv2

Grid1.DataBind()

hidePanel()

End Sub

Paging in DataGrid

The DataGrid has a built-in pager control, which displays a user-defined number of pages per page, and also numeric or next/previous buttons at the bottom of the DataGrid. Clicking on these links displays the next set of pages. To enable paging, you set a number of properties as follows:

<asp:DataGrid id="Grid1" runat="server"

AllowPaging="True"

PageSize="3"

PagerStyle-Mode="NumericPages"

PagerStyle-HorizontalAlign="Right"

PagerStyle-NextPageText="Next"

PagerStyle-PrevPageText="Prev"

OnPageIndexChanged="MyDataGrid_Page">

The AllowPaging property must be set to true to enable paging. The PageSize property sets the number of records per page. A PageSize of 3 implies that only three records per page will be shown. If you leave out the PagerStyleMode="NumericPages" property, then instead of numeric links at the bottom, you get two links: next and previous. The PagerStyle-NextPageText and the

PagerStyle-PrevPageText properties are descriptive captions for these two links and they can be any text you want. You are required to code one event. This is the OnPageIndexChanged event, which fires off the MyDataGrid_Page event. You simply call the ReBind function in this event as follows:

Sub MyDataGrid_Page(sender As Object, e As DataGridPageChangedEventArgs)

ReBind

End Sub

Here is the complete listing of StockMaster.aspx.

StockMaster.aspx

<%@Page Language="VB" Inherits="BaseClass" Src="stockmasters.vb" %>

<%@ Import Namespace="System.Data" %>

<%@ Import Namespace="System.Data" %>

<%@ Import Namespace="System.Data.OleDb" %>

<%@ Register TagPrefix="Hersh" TagName="nav" Src="nav.ascx" %>

<html>

<script language="VB" runat="server">

Sub Grid1_Update(sender As Object, e As DataGridCommandEventArgs)

Dim sql As string

Dim code_display As String

Dim rate As String

Dim uom As String

Dim opening As String

Dim closing As String

Dim myTextBox As TextBox

'This is the key value:

'Retrieved from the DataKey, since it's a read only field

Dim code_value As string = Grid1.DataKeys.Item(E.Item.ItemIndex).ToString myTextBox = E.Item.FindControl("edit_name")

code_display = mytextbox.text

myTextBox = E.Item.FindControl("edit_rate") rate = mytextbox.text

myTextBox = E.Item.FindControl("edit_uom") uom = mytextbox.text

myTextBox = E.Item.FindControl("edit_opening") opening = mytextbox.text

myTextBox = E.Item.FindControl("edit_closing") closing = mytextbox.text

'Now execute stored procedure

sql = "Execute p_Stock_master @code_value ="

sql = sql+code_value+", @code_display = '"+code_display+"',@rate="

sql = sql+rate+", @uom='"+uom +"' ,@opening ="+opening+",@closing="+closing RunSql(sql)

End Sub

Sub add_click(Source As Object, E As EventArgs)

Dim sql As string

if acode_display.text = "" then response.write("Incomplete information") exit sub

end if

SQL = "Execute p_stock_master @code_value=NULL,@code_display='" SQL = SQL+ acode_display.text + "',@rate="

SQL = SQL+arate.Text+",@uom="+auom.text+",@opening="+aopening.text

RunSql(sql)

'reset values acode_display.text = "" aopening.text = ""

arate.text = "" auom.text = "" hidePanel()

End Sub

Sub add_show(Source As Object, E As EventArgs)

AddPanel.visible = true

End Sub

Sub Grid1_delete(sender As Object, e As DataGridCommandEventArgs)

Dim code_value As string = Grid1.DataKeys.Item(E.Item.ItemIndex).ToString Dim sql As string

sql = "Delete from stock_master where code_value = " + cstr(code_value) RunSql(sql)

End Sub

Sub MyDataGrid_Page(sender As Object, e As DataGridPageChangedEventArgs)

Grid1.CurrentPageIndex = e.NewPageIndex

ReBind

End Sub

Sub MyDataGrid_Sort(sender As Object, e As DataGridSortCommandEventArgs)

SortField = e.SortExpression

ReBind

End Sub </script> <head>

<style>

a { color:black; text-decoration:none;}

a:hover { color:red; text-decoration:underline;}

</style>

</head>

<body style="font: 10pt verdana; background-color:ivory"> <form runat="server">

<asp:ValidationSummary runat=server headertext="There were errors on the page:" /> <!—— Navigation Start———————>

<Hersh:nav id="menu" runat = server vGridlines = Both

vBorderColor = "Black" vCellPadding = 7 />

<!—— Navigation Ends———————>

<h3><font face="Verdana">Inventory Masters </font></h3> <asp:Label id="Message" runat="server"/>

<asp:Button id="Addshow" text="Add Account" onclick="add_show" runat="server" /> <table width="95%">

<tr>

<td valign="top">

<asp:DataGrid id="Grid1" runat="server" AutoGenerateColumns="false" BackColor="White"

BorderWidth="1px" BorderStyle="Solid" BorderColor="Tan"

CellPadding="2" CellSpacing="0"

Font-Name="Verdana" Font-Size="8pt"

OnEditCommand="Grid1_Edit"

OnCancelCommand="Grid1_Cancel"

OnUpdateCommand="Grid1_Update"

OnDeleteCommand = "Grid1_delete"

DataKeyField="code_value"

AllowPaging="True"

PageSize="20"

PagerStyle-Mode="NumericPages"

PagerStyle-HorizontalAlign="Right"

PagerStyle-NextPageText="Next"

PagerStyle-PrevPageText="Prev" OnPageIndexChanged="MyDataGrid_Page" AllowSorting="true" OnSortCommand="MyDataGrid_Sort"> <Columns>

<asp:EditCommandColumn

EditText="Edit"

CancelText="Cancel"

UpdateText="OK"

ItemStyle-Wrap="false"

HeaderText="Edit"

HeaderStyle-Wrap="false"/>

<asp:ButtonColumn Text="Delete" CommandName="Delete" HeaderText="Delete"/>

<asp:BoundColumn HeaderText="Account #" ReadOnly="true" DataField="code_value" SortExpression="code_value" />

<asp:TemplateColumn HeaderText="Name" SortExpression="code_display">

<ItemTemplate>

<asp:Label Text='<%# Container.DataItem("code_display") %>' runat="server"/>

</ItemTemplate>

<EditItemTemplate> <asp:RequiredFieldValidator runat=server

controltovalidate=edit_Name errormessage="Name is required.">*

</asp:RequiredFieldValidator> <asp:TextBox id="edit_name"

Text='<%# Container.DataItem("code_display") %>' runat="server"/>

</EditItemTemplate>

</asp:TemplateColumn>

<asp:TemplateColumn HeaderText="Rate" SortExpression="rate" > <ItemTemplate>

<asp:Label Text='<%# Container.DataItem("rate") %>' runat="server" /> </ItemTemplate>

<EditItemTemplate>

<asp:TextBox id="edit_rate" Text='<%# Container.DataItem("rate") %>' runat="server"/>

</EditItemTemplate>

</asp:TemplateColumn>

<asp:TemplateColumn HeaderText="uom" SortExpression="uom" > <ItemTemplate>

<asp:Label Text='<%# Container.DataItem("uom") %>' runat="server"/> </ItemTemplate>

<EditItemTemplate>

<asp:TextBox id="edit_uom" Text='<%# Container.DataItem("uom") %>' runat="server"/>

</EditItemTemplate>

</asp:TemplateColumn>

<asp:TemplateColumn HeaderText="Opening" > <ItemTemplate>

<asp:Label Text='<%# Container.DataItem("opening") %>' runat="server"/> </ItemTemplate>

<EditItemTemplate> <asp:TextBox id="edit_opening"

Text='<%# Container.DataItem("opening") %>' runat="server"/>

</EditItemTemplate>

</asp:TemplateColumn> <asp:TemplateColumn HeaderText="Closing" >

<ItemTemplate>

<asp:Label Text='<%# Container.DataItem("closing") %>' runat="server"/>

</ItemTemplate>

<EditItemTemplate>

<asp:TextBox id="edit_closing" BorderStyle="None" Readonly="True" Text='<%# Container.DataItem("closing") %>'

runat="server"/>

</EditItemTemplate>

</asp:TemplateColumn>

</Columns>

<HeaderStyle BackColor="Gray" ForeColor="White" Font-Bold="true"/>

<ItemStyle ForeColor="DarkSlateBlue"/>

<AlternatingItemStyle BackColor="Beige"/> </asp:DataGrid>

</td>

<td valign="top">

<!---- insert row logic-------->

<asp:Panel id="AddPanel" runat="server" Visible="false"> <table style="font: 8pt verdana">

<tr>

<td colspan="2" bgcolor="#aaaadd" style="font:10pt verdana"> Add a New Account:</td>

</tr>

<tr>

<td nowrap>Name: </td>

<td><asp:TextBox id="acode_display" runat="server" /></td>