如何使用自定义验证器取决于下拉值 | 如何使用自定义验证器取决于下拉值

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问题描述

Hi all,

i have come confusion, how can we achieve this goal

for example, i have a dropdown, which the item is HR, Admin, IT

eg : <asp:DropDownList ID="DropDownList22" runat="server" OnSelectedIndexChanged="DropDownList22_SelectedIndexChanged" AutoPostBack="true" >
    <asp:ListItem>IT</asp:ListItem>
    <asp:ListItem>Admin</asp:ListItem>
    <asp:ListItem>HR</asp:ListItem>
</asp:DropDownList>

so, i want to put my validation here in date textbox, only if user select IT, this textbox will validate, for other (Admin and HR) they can left the date empty

<asp:TextBox ID="TextBox32" runat="server" AutoPostBack="true" OnTextChanged="TextBox32_TextChanged"></asp:TextBox>

what kind of validator can i use and how are the validator can be made?
i already try put requiredvalidator, but if i select admin and left the field empty, i got the errormessage too.

<asp:RequiredFieldValidator ID="chkDateReturn" runat="server" ControlToValidate="TextBox32" ErrorMessage="Must select the return date" ></asp:RequiredFieldValidator>

thanks

推荐答案

protected void Page_Load(object sender, EventArgs e)
    {
        if (!this.IsPostBack)
        {
            if (DropDownList22.SelectedItem.Text == "IT")
            {
                Button1.CausesValidation = true;
            }
            else
            {
                Button1.CausesValidation = false;
            }
        }
    }

    protected void DropDownList22_SelectedIndexChanged(object sender, EventArgs e)
    {
        if (DropDownList22.SelectedItem.Text == "IT")
        {
            Button1.CausesValidation = true;
        }
        else
        {
            Button1.CausesValidation = false;
        }
    }

以下HTML代码..

HTML code below..

<asp:DropDownList ID="DropDownList22" runat="server" OnSelectedIndexChanged="DropDownList22_SelectedIndexChanged"

            AutoPostBack="true">
            <asp:ListItem>IT</asp:ListItem>
            <asp:ListItem>Admin</asp:ListItem>
            <asp:ListItem>HR</asp:ListItem>
        </asp:DropDownList>
        <asp:TextBox ID="TextBox32" runat="server" AutoPostBack="true" OnTextChanged="TextBox32_TextChanged"></asp:TextBox>
        <asp:RequiredFieldValidator ID="chkDateReturn" runat="server" ControlToValidate="TextBox32"

            ErrorMessage="Must select the return date"></asp:RequiredFieldValidator>
        <asp:Button ID="Button1" runat="server" Text="Button" CausesValidation="false" />

希望它可以帮助你..

Hope it helps you..

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