Question

我有3个下拉列表，每个下拉列表中都有相同的值，例如a，b和c

例如：如果我从下拉列表中选择“a”，并且选择了相同值“a”的另一个下拉列表。我应该得到一个错误的消息。

这怎么可能。

Answer 1

像这样使用CompareValidator控件：

<form id="form1" runat="server">
    <div>
        <asp:DropDownList ID="ddl1" runat="server">
            <asp:ListItem Text="a" Value="a"></asp:ListItem>
            <asp:ListItem Text="b" Value="b"></asp:ListItem>
        </asp:DropDownList>
        <asp:DropDownList ID="ddl2" runat="server">
            <asp:ListItem Text="a" Value="a"></asp:ListItem>
            <asp:ListItem Text="b" Value="b"></asp:ListItem>
        </asp:DropDownList>
        <asp:DropDownList ID="ddl3" runat="server">
            <asp:ListItem Text="a" Value="a"></asp:ListItem>
            <asp:ListItem Text="b" Value="b"></asp:ListItem>
        </asp:DropDownList>
        <asp:CompareValidator ID="CompareValidator1" runat="server"
            ErrorMessage="DropDownList 1 can't be equal DropDownList 2"
            ControlToCompare="ddl1" ControlToValidate="ddl2" Operator="NotEqual"></asp:CompareValidator>
        <asp:CompareValidator ID="CompareValidator2" runat="server"
            ErrorMessage="DropDownList 2 can't be equal DropDownList 3"
            ControlToCompare="ddl2" ControlToValidate="ddl3" Operator="NotEqual"></asp:CompareValidator>
         <asp:CompareValidator ID="CompareValidator3" runat="server"
            ErrorMessage="DropDownList 1 can't be equal DropDownList 3"
            ControlToCompare="ddl2" ControlToValidate="ddl3" Operator="NotEqual"></asp:CompareValidator>
    </div>
</form>

如何防止具有相同值集的下拉列表选择相同的值？

1 个答案: