bills.aspx

asp入门到精通的源代码

<%@ Page language="Vb" %>
<%@ Register TagPrefix="ASPNETBank" TagName="Header" src="header.ascx" %>
<%@ Register TagPrefix="ASPNETBank" TagName="Menu" src="nav.ascx" %>
<%@ Import Namespace="System.Data" %>
<%@ Import Namespace="System.Data.OleDb" %>

<script runat="server">

   '*******************************************************
   '
   ' Bills.aspx: Allows user to pay bills online
   '
   '*******************************************************
   'declare connection object
   dim Conn as new OleDbConnection("Provider=" & _
      "Microsoft.Jet.OLEDB.4.0;" & _
      "Data Source=C:\ASPNET\data\banking.mdb")
   
   '*******************************************************
   ' Event hander for submit button. Determines if amount
   ' is valid, and if so, calls necessary functions to 
   ' update balance and add transaction
   '*******************************************************
   sub PayBill(obj as object, e as eventargs)
      dim decBalance as Decimal = GetBalance
      dim decAmount as Decimal = tbAmount.Text
      
      if decAmount < 0 then
         lblMessage.Text = "<font color=red>The " & _
            "transaction amount cannot be negative!" & _
            "</font>"
         exit sub
      end if
      
      if decAmount <= decBalance then
         UpdateBalance(decBalance - decAmount)
         AddTransaction(tbPayee.Text, decAmount)
         
         lblMessage.Text = "<font color=red>Transaction " & _
            "added.</font>"
         tbAmount.Text = ""
         tbPayee.Text = ""
      else
         lblMessage.Text = "<font color=red>You do not " & _
            "have enough funds to complete this " & _
            "transaction!</font>"
      end if
   end sub   
   
   '*******************************************************
   ' This function returns the balance of the account with
   ' the specified user ID (stored in the cookie created
   ' by forms authentication)
   '*******************************************************
   function GetBalance as Decimal
      dim decBalance as decimal
      dim objCmd as OleDbCommand = new OleDbCommand _
         ("spRetrieveBalance", Conn)
      objCmd.CommandType = CommandType.StoredProcedure
      dim objReader as OleDbDataReader
      
      'set parameters for stored procedure
      dim objParam as OleDbParameter
      objParam = objCmd.Parameters.Add("@UserID", _
         OleDbType.BSTR)
      objParam.Direction = ParameterDirection.Input
      objParam.Value = Request.Cookies("Account").Value
      
      try
         objCmd.Connection.Open()
         decBalance = CType(objCmd.ExecuteScalar, Decimal)
         objCmd.Connection.Close()
      catch ex as OleDbException
         lblMessage.Text = ex.Message
      end try
      
      return decBalance
   end function
   
   '*******************************************************
   ' Adds a transaction into the database, calling
   ' spInsertTransaction and specifying amount, payee, and
   ' user id
   '*******************************************************
   sub AddTransaction(strPayee as string, decAmount _
      as Decimal)
      dim objCmd as OleDbCommand = new OleDbCommand _
         ("spInsertTransaction", Conn)
      objCmd.CommandType = CommandType.StoredProcedure
         
      'set parameters for stored procedure
      dim objParam as OleDbParameter
      objParam = objCmd.Parameters.Add("@Date", _
         OleDbType.Date)
      objParam.Direction = ParameterDirection.Input
      objParam.Value = Datetime.Now
      
      objParam = objCmd.Parameters.Add("@Amount", _
         OleDbType.Decimal)
      objParam.Direction = ParameterDirection.Input
      objParam.Value = decAmount
      
      objParam = objCmd.Parameters.Add("@Payee", _
         OleDbType.BSTR)
      objParam.Direction = ParameterDirection.Input
      objParam.Value = strPayee
      
      objParam = objCmd.Parameters.Add("@UserID", _
         OleDbType.BSTR)
      objParam.Direction = ParameterDirection.Input
      objParam.Value = Request.Cookies("Account").Value
         
      try
         objCmd.Connection.Open()
         objCmd.ExecuteNonQuery
      catch ex as OleDbException
         lblMessage.Text = ex.Message
      finally
         objCmd.Connection.Close()
      end try
   end sub
   
   '*******************************************************
   ' Updates the account balance
   ' calls spUpdateBalance
   '*******************************************************
   sub UpdateBalance(decNewAmount as Decimal)
      dim objCmd as OleDbCommand = new OleDbCommand _
         ("spUpdateBalance", Conn)
      objCmd.CommandType = CommandType.StoredProcedure
         
      'set parameters for stored procedure
      dim objParam as OleDbParameter
      objParam = objCmd.Parameters.Add("@NewBalance", _
         OleDbType.Decimal)
      objParam.Direction = ParameterDirection.Input
      objParam.Value = decNewAmount
      
      objParam = objCmd.Parameters.Add("@UserID", _
         OleDbType.BSTR)
      objParam.Direction = ParameterDirection.Input
      objParam.Value = Request.Cookies("Account").Value
         
      try
         objCmd.Connection.Open()
         objCmd.ExecuteNonQuery
      catch ex as OleDbException
         lblMessage.Text = ex.Message
      finally
         objCmd.Connection.Close()
      end try
   end sub
</script>

<html><body>
   <ASPNETBank:Header runat="server" />
   
    <table>
    <tr>
       <td valign="top" width="150">
          <ASPNETBank:Menu runat="server" />
       </td>
       <td width="550" valign="top">
          <font face="arial">
	      <asp:Label id="lblMessage" runat="server"/>
	      <form runat="server">
             <table>
             <tr>
                <td width="10">
                   &nbsp;
                </td>
                <td width="100%">
                   <font face="arial">
                   &nbsp;<p>
                   Welcome to the bill paying service!
                   Please fill out the information below
                   and hit "Pay that Bill!" to automatically
                   transfer available funds.<p>
                   
                   <table>
                   <tr>
                      <td width="150" valign="top">
                         <font face="arial">
                         Payee:
                      </td>
                      <td width="100" valign="top">
                         <font face="arial">
                         <asp:textbox id="tbPayee" runat="server"/>
                      </td>
                   </tr>
                   <tr>
                      <td valign="top">
                         <font face="arial">
                         Amount:
                      </td>
                      <td valign="top">
                         <font face="arial">
                         <asp:textbox id="tbAmount" runat="server"/>
                      </td>
                   </tr>
                   <tr>
                      <td valign="top" colspan="2" align="right">
                         <font face="arial">
                         <asp:button id="btSubmit" runat="server"
                            text="Pay That Bill!"
                            OnClick="PayBill" />
                      </td>
                   </tr>
                   </table>
                   </font>
                </td>
             </tr>
             </table>
	      
	      
	      </form>
   
	      </font>
	   </td>
	</tr>
	</table>   
      
   </font>
</BODY>
</HTML>