单选按钮和下拉列表之间的依赖关系

Question

我有这样的代码

protected void RadioButton1_CheckedChanged(object sender, EventArgs e)
{
    if (RadioButton1.Checked)
    {
        RadioButton2.Checked = false;
        DropDownList1.Enabled = true;
    }
    if (!RadioButton1.Checked)
    {
        RadioButton2.Checked = true;
    }
}
protected void RadioButton2_CheckedChanged(object sender, EventArgs e)
{
    if (RadioButton2.Checked)
    {
        RadioButton1.Checked = false;
        DropDownList1.Enabled = false;
    }
    if (!RadioButton1.Checked)
    {
        RadioButton1.Checked = true;
    }
}
<asp:DropDownList   ID="DropDownList1"  runat="server" DataSourceID="BookStore" DataTextField="Name" DataValueField="Name"  Height="51px" Width="300px" DataMember="DefaultView">
</asp:DropDownList>
<asp:SqlDataSource ID="BookStore" runat="server" ConnectionString="<%$ ConnectionStrings:BookStoreConnectionString %>" SelectCommand="SELECT [Name] FROM [Books] ORDER BY [Name]"></asp:SqlDataSource>
<p>
    <asp:RadioButton ID="RadioButton1" runat="server" Checked="True" GroupName="1" OnCheckedChanged="RadioButton1_CheckedChanged" />
    <asp:RadioButton ID="RadioButton2" runat="server" GroupName="1" OnCheckedChanged="RadioButton2_CheckedChanged" />
</p>

但是当我点击单选按钮时，下拉列表总是启用的。当我在webforms应用程序(不是asp.net)中编写此功能时，其工作正确。这种不正常工作的原因是什么?

Answer 1

可能是RadioButton2_CheckedChanged事件在第二if条件下的问题，这应该检查RadioButton2.Checked而不是RadioButton1.Checked。而不是检查这个条件，如果你把else仍然这将工作，不需要再次检查。

if (!RadioButton2.Checked)
{
    RadioButton1.Checked = true;
}