ASP.NET中使用自定义验证控件(原作)

类别:.NET开发 点击:0 评论:0 推荐:
   asp.net 1.1中,有不少验证控件,大大方便了我们,但有的时候,当需要做特殊的验证时,还会觉得不够用的,于是我们可以用自定义验证控件CustomValidator,要使用这个控件,必须在服务端写相应的事件,格式如下:

Sub FunctionName(sender as Object, args as ServerValidateEventArgs) ... End Sub 其中注意两个参数
value:指示当前的CustomValidator验证的是哪一个控件
IsValid:为真时,表示页面控件已经通过验证。
举一个验证页面中文本框的输入是否为素数的例子:

<script language="vb" runat="server"> Sub btnSubmit_Click(sender as Object, e as EventArgs) If Page.IsValid then Response.Write("<font color=""red""><i>" & txtPrimeNumber.Text & _ " is, indeed, a good prime number.</i></font>") Else Response.Write("<font color=""red""><i>" & txtPrimeNumber.Text & _ " is <b>not</b> a prime number.</i></font>") End If End Sub Sub PrimeNumberCheck(sender as Object, args as ServerValidateEventArgs) Dim iPrime as Integer = Cint(args.Value), iLoop as Integer, _ iSqrt as Integer = CInt(Math.Sqrt(iPrime)) For iLoop = 2 to iSqrt If iPrime mod iLoop = 0 then args.IsValid = False Exit Sub End If Next args.IsValid = True End Sub </script> <form method="post" runat="server"> Enter your favorite prime number: <asp:textbox id="txtPrimeNumber" runat="server" /> <%-- Create the CustomValidator control --%> <asp:CustomValidator runat="server" id="custPrimeCheck" ControlToValidate="txtPrimeNumber" OnServerValidate="PrimeNumberCheck" ErrorMessage="Invalid Prime Number" /> <%-- Create two CompareValidator controls: the first ensures that the number entered by the user is an Integer; the second makes sure it is positive. --%> <asp:CompareValidator runat="server" id="compPrimeNumber" Operator="DataTypeCheck" Type="Integer" Display="Dynamic" ControlToValidate="txtPrimeNumber" ErrorMessage = "You must enter an integer value." /> <asp:CompareValidator runat="server" id="compPrimeNumberPositive" Operator="GreaterThan" Type="Integer" Display="Dynamic" ValueToCompare="0" ControlToValidate="txtPrimeNumber" ErrorMessage = "You must enter a value greater than zero." /> <p><asp:button id="btnSubmit" runat="server" OnClick="btnSubmit_Click" Text="Submit" /> </form> 可以看到,在验证控件中, OnServerValidate="PrimeNumberCheck"中,要定义具体的onservervalidate事件 ,之后,在具体的事件处理过程中,一定要返回args.isvalid的值,以价讲明是否验证成功;当然,最后要用page.isvalid属性
来进行全面验证

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