C# 在单选按钮上显示模式弹出窗口单击

您将在触发事件后分配TargetControlID，因此无法获得所需的输出。 只需删除以下行：

protected void rdoBtnleaveWoNoticeyes_CheckedChanged(object sender, EventArgs e)
{
    if (rdoBtnleaveWoNoticeyes.Checked == true)
    {
        lbl_leaveWoNotice.Text = "As you have asked the employee to leave without serving notice, there will be no Notice recovery from employee and employee will receive his PL encashment treating this as “Ask to leave” case.";
        trNoticePayRecovery.Visible = true;
        cc18_ModalPopupExtender.TargetControlID = "rdoBtnleaveWoNoticeyes";
        cc18_ModalPopupExtender.Show();
    }
}

protected void rdoBtnleaveWoNoticeno_CheckedChanged(object sender, EventArgs e)
{
    lbl_leaveWoNotice.Text = "As process there will be Notice period shortfall recovery with PL bal adjustment from employee.";               
    trNoticePayRecovery.Visible = false;
    cc18_ModalPopupExtender.TargetControlID = "rdoBtnleaveWoNoticeno";
    cc18_ModalPopupExtender.Show();
}

也许对你有帮助

protected void rdoBtnleaveWoNoticeyes_CheckedChanged(object sender, EventArgs e)
{
    if (rdoBtnleaveWoNoticeyes.Checked == true)
    {
        lbl_leaveWoNotice.Text = "As you have asked the employee to leave without serving notice, there will be no Notice recovery from employee and employee will receive his PL encashment treating this as “Ask to leave” case.";
        trNoticePayRecovery.Visible = true;
        cc18_ModalPopupExtender.TargetControlID = "rdoBtnleaveWoNoticeyes";
        cc18_ModalPopupExtender.Show();
    }
}

protected void rdoBtnleaveWoNoticeno_CheckedChanged(object sender, EventArgs e)
{
    lbl_leaveWoNotice.Text = "As process there will be Notice period shortfall recovery with PL bal adjustment from employee.";               
    trNoticePayRecovery.Visible = false;
    cc18_ModalPopupExtender.TargetControlID = "rdoBtnleaveWoNoticeno";
    cc18_ModalPopupExtender.Show();
}

cc18_ModalPopupExtender.TargetControlID = "rdoBtnleaveWoNoticeno";


cc18_ModalPopupExtender.TargetControlID = "rdoBtnleaveWoNoticeyes";