为什么我必须显式地启用和禁用单选按钮?

当我想使用Ajax更改RadioButton的状态时,我发现有必要显式地设置每个RadioButton的状态,而不仅仅是设置 Checked = true 在您想要启用的那个上。如果我删除下面标记的行,我可以使用按钮更改一次或两次RadioButtons状态,但不能再更改。

有人能解释这是为什么吗?必须明确地取消选中其他单选按钮,而不是我要选中的按钮,这感觉是多余的。

ASP代码

<div>
    <asp:UpdatePanel ID="UP_Checkboxes" UpdateMode="Conditional" runat="server">
        <ContentTemplate>
            <asp:RadioButton ID="RadioButton1" runat="server" GroupName="MyRBs" /><br />
            <asp:RadioButton ID="RadioButton2" runat="server" GroupName="MyRBs" /><br />
            <asp:RadioButton ID="RadioButton3" runat="server" GroupName="MyRBs" />
        </ContentTemplate>
    </asp:UpdatePanel>
</div>
<div>
    <asp:UpdatePanel ID="UP_Buttons" runat="server" UpdateMode="Conditional">
        <ContentTemplate>
            <asp:Button ID="Button1" runat="server" Text="Select 1" OnClick="Button1_Click" /><br />
            <asp:Button ID="Button2" runat="server" Text="Select 2" OnClick="Button2_Click" /><br />
            <asp:Button ID="Button3" runat="server" Text="Select 3" OnClick="Button3_Click" />
        </ContentTemplate>
    </asp:UpdatePanel>
</div>

CS代码

protected void Button1_Click(object sender, EventArgs e)
{
    RadioButton1.Checked = true;
    RadioButton2.Checked = false; // Removing these lines causes problems
    RadioButton3.Checked = false; // Removing these lines causes problems
    UP_Checkboxes.Update();
}

protected void Button2_Click(object sender, EventArgs e)
{
    RadioButton1.Checked = false; // Removing these lines causes problems
    RadioButton2.Checked = true;
    RadioButton3.Checked = false; // Removing these lines causes problems
    UP_Checkboxes.Update();
}

protected void Button3_Click(object sender, EventArgs e)
{
    RadioButton1.Checked = false; // Removing these lines causes problems
    RadioButton2.Checked = false; // Removing these lines causes problems
    RadioButton3.Checked = true;
    UP_Checkboxes.Update();
}