我正在尝试从我的数据库中获取一个值并自动添加它以进行计算。我想我只是有点想念。请帮忙。谢谢
SCRIPT <%@ Import Namespace="System.Data" %> <%@ Import Namespace="System.Data.Odbc" %> <%@ Import Namespace="Microsoft.Data.Odbc" %> <%@ Page Language= "VB" AutoEventWireup="false" CodeFile="web.aspx.vb" Inherits="_default" %>
<HTML>
<HEAD>
<SCRIPT Language="VB" Runat="server">
Sub Page_Load(Source as object, e as EventArgs)
Dim connectionstring As String = "DRIVER={MySQL ODBC 5.2 Unicode Driver}; SERVER=localhost; DATABASE=mydb; UID=andrew; PASSWORD=kh12345; OPTION=3"
Dim connectme As OdbcConnection = New OdbcConnection(connectionstring)
Dim sqlquery As String = "SELECT f_price from tbl_picture WHERE f_ID = 1"
Dim ODBCdataadapter As OdbcDataAdapter = New OdbcDataAdapter(sqlquery, connectme)
Dim ODBCdataset As DataSet = New DataSet()
ODBCdataadapter.Fill(ODBCdataset,"f_price")
amount.Text = ODBCdataset.Tables("f_price").Rows(0).Item(0)
End Sub
</SCRIPT >
</HEAD>
<BODY>
<form id="form1" runat="server">
<h1>Table</h1>
<table width="234" border="0
" cellspacing="0" cellpadding="0">
<tr>
<td width="234" height="30" align="left"><h3> Car Loan Calculator</h3></td>
</tr>
<tr>
<td width="234" height="160"><table width="230" border="0" align="center" cellpadding="0" cellspacing="0">
<tr>
<td width="135" height="40"> Total Amount</td>
<td width="95" height="40">RM
<asp:Label ID="amount" runat="server" Text="Label"></asp:Label>
</td>
</tr>
<tr>
<td width="135" height="40"> Down Payment</td>
<td width="95" height="40"><asp:DropDownList ID="Down" AutoPostBack="true" runat="server" OnSelectedIndexChanged="Down_SelectedIndexChanged">
<asp:ListItem Value="10">10%</asp:ListItem>
<asp:ListItem Value="20">20%</asp:ListItem>
<asp:ListItem Selected="True" Value="30">30%</asp:ListItem>
<asp:ListItem Value="40">40%</asp:ListItem>
<asp:ListItem Value="50">50%</asp:ListItem>
</asp:DropDownList></td>
</tr>
<tr>
<td width="135" height="40"> Interest Rate %</td>
<td width="95" height="40"><asp:DropDownList ID="Interest" AutoPostBack="true" runat="server" OnSelectedIndexChanged="Interest_SelectedIndexChanged">
<asp:ListItem Selected="True" Value="2">2%</asp:ListItem>
<asp:ListItem Value="2.5">2.5%</asp:ListItem>
<asp:ListItem Value="3.0">3.0%</asp:ListItem>
<asp:ListItem Value="3.5">3.5%</asp:ListItem>
<asp:ListItem Value="4.0">4.0%</asp:ListItem>
</asp:DropDownList></td>
</tr>
<tr>
<td width="135" height="40"> Period Of Years</td>
<td width="95" height="40"><asp:DropDownList AutoPostBack="true" ID="Year" runat="server" OnSelectedIndexChanged="Year_SelectedIndexChanged" >
<asp:ListItem Value="1">1</asp:ListItem>
<asp:ListItem Value="2">2</asp:ListItem>
<asp:ListItem Value="3">3</asp:ListItem>
<asp:ListItem Value="4">4</asp:ListItem>
<asp:ListItem Value="5">5</asp:ListItem>
<asp:ListItem Value="6">6</asp:ListItem>
<asp:ListItem Value="7">7</asp:ListItem>
<asp:ListItem Value="8">8</asp:ListItem>
<asp:ListItem Selected="True" Value="9">9</asp:ListItem>
</asp:DropDownList></td>
</tr>
</table></td>
</tr>
<tr>
<td width="234" height="40" align="center"><h4>Monthly :
<asp:Label ID="Payment" runat="server" Text="Label"></asp:Label>
</h4></td>
</tr>
</table>
<p>
</p>
</form>
</BODY>
</HTML>
背书
Partial Class _Default
Inherits System.Web.UI.Page
Private Sub CalculatePayment()
Dim c_loan_amount, c_Payment
c_loan_amount = amount.Text - (amount.Text * Down.Text * 0.01)
c_Payment = ((c_loan_amount * (Interest.Text * 0.01) * Year.Text) + c_loan_amount) / (Year.Text * 12)
Payment.Text = "RM " & Format(c_Payment, "#,##0.00")
End Sub
Sub Page_Load(ByVal Sender As Object, ByVal e As EventArgs) Handles Me.Load
Call CalculatePayment()
End Sub
Protected Sub Year_SelectedIndexChanged(sender As Object, e As EventArgs) Handles Year.SelectedIndexChanged
Call CalculatePayment()
End Sub
Protected Sub Interest_SelectedIndexChanged(sender As Object, e As EventArgs) Handles Interest.SelectedIndexChanged
Call CalculatePayment()
End Sub
Protected Sub Down_SelectedIndexChanged(sender As Object, e As EventArgs) Handles Down.SelectedIndexChanged
Call CalculatePayment()
End Sub
End Class
错误是 System.FormatException：输入字符串的格式不正确。