C# 如何在usercontrol dropdownlist中绑定值？

我绑定usercontrol dropdownlist中的值

但当我添加usercontrol行时，时间值不会绑定到dropdownlist中

代码：

.ascx

.aspx

.aspx.cs

    protected void Page_Load(object sender, EventArgs e)
    {
      if(!IsPostback)
      {
       BindActivities();
      }
    }

    protected void BindActivities()
    {
        DropDownList dropActivities = Timesheet.FindControl("DropDownActivities") as DropDownList;
        DbConnection.Open();
        OleDbCommand cmd1 = new OleDbCommand("select designation from emp_master where username = '" + username + "'", DbConnection);
        OleDbDataAdapter da = new OleDbDataAdapter(Deptcmd);
            DataSet ds = new DataSet();
            da.Fill(ds);
            // DbConnection.Close();
            dropActivities.DataSource = ds;
            dropActivities.DataTextField = "ActivityName";
            dropActivities.DataBind();
            dropActivities.Items.Insert(0, new ListItem("--Select--", "0"));
   }

    public List<string> NoOfControls
    {
        get
        {
            return ViewState["NoOfControls"] == null ? new List<string>() : (List<string>)ViewState["NoOfControls"];

        }
        set
        {
            ViewState["NoOfControls"] = value;
        }
    }

    protected override void LoadViewState(object savedState)
    {
        base.LoadViewState(savedState);

        if (IsPostBack)
        {
            GenerateControls();

        }

    }

    private void GenerateControls()
    {
        foreach (string i in NoOfControls)
        {
            TimesheetUserControl ctrl = (TimesheetUserControl)Page.LoadControl("TimesheetUserControl.ascx");

            ctrl.ID = i;
            this.rpt1.Controls.Add(ctrl);
        }

    }

    protected void ButtonAdd_Click(object sender, EventArgs e)
    {
        Button thisButton = (Button)sender;
        List<string> temp = null;
        var uc = (TimesheetUserControl)this.LoadControl(@"TimesheetUserControl.ascx");

        string id = Guid.NewGuid().ToString();
        uc.ID = id;

        temp = NoOfControls;
        temp.Add(id);
        NoOfControls = temp;
        rpt1.Controls.Add(uc);

    }

受保护的无效页面加载（对象发送方，事件参数e）
{
如果（！IsPostback）
{
绑定活动（）；
}
}
受保护的活动（）
{
DropDownList dropActivities=时间表。FindControl（“DropDownActivities”）作为DropDownList；
DbConnection.Open（）；
OleDbCommand cmd1=新的OleDbCommand（“从emp_主机中选择名称，其中username='“+username+'”，DbConnection）；
OleDbDataAdapter da=新的OleDbDataAdapter（Deptcmd）；
数据集ds=新数据集（）；
da.填充（ds）；
//DbConnection.Close（）；
dropActivities.DataSource=ds；
dropActivities.DataTextField=“ActivityName”；
dropActivities.DataBind（）；
插入（0，newlistItem（“--Select--”，0”）；
}
公共列表NoOfControls
{
得到
{
返回ViewState[“NoOfControls”]==null？新建列表（）：（列表）ViewState[“NoOfControls”]；
}
设置
{
ViewState[“NoOfControls”]=值；
}
}
受保护的覆盖无效LoadViewState（对象保存状态）
{
base.LoadViewState（savedState）；
如果（iPostBack）
{
生成控件（）；
}
}
私有void GenerateControls（）
{
foreach（NoOfControls中的字符串i）
{
TimesheetUserControl ctrl=（TimesheetUserControl）Page.LoadControl（“TimesheetUserControl.ascx”）；
ctrl.ID=i；
this.rpt1.Controls.Add（ctrl）；
}
}
受保护的无效按钮单击（对象发送者，事件参数e）
{
按钮thisButton=（按钮）发送器；
列表温度=空；
var uc=（TimesheetUserControl）this.LoadControl（@“TimesheetUserControl.ascx”）；
字符串id=Guid.NewGuid（）.ToString（）；
uc.ID=ID；
温度=无控制；
临时添加（id）；
NoOfControls=温度；
rpt1.控件.添加（uc）；
}

在下图中，如果单击“添加”按钮，则会添加行，但第二个值不会绑定到dropdownlist中

---

有什么想法吗？提前感谢。

根据您提供的id查找用户控件，然后您可以在用户控件内找到

下拉列表

protected void BindActivities()
{
    foreach (string controlName in NoOfControls)
    {
        TimesheetUserControl  userControl = Timesheet.FindControl(controlName) as TimesheetUserControl;
        if(userControl == null) return;
        DropDownList dropActivities = userControl.FindControl("DropDownActivities") as DropDownList;
        if(dropActivities == null) return;
        DbConnection.Open();
        OleDbCommand cmd1 = new OleDbCommand("select designation from emp_master where username = '" + username + "'", DbConnection);
        OleDbDataAdapter da = new OleDbDataAdapter(Deptcmd);
        DataSet ds = new DataSet();
        da.Fill(ds);
        // DbConnection.Close();
        dropActivities.DataSource = ds;
        dropActivities.DataTextField = "ActivityName";
        dropActivities.DataBind();
        dropActivities.Items.Insert(0, new ListItem("--Select--", "0"));
    }
}

根据您给定的id查找用户控件，然后可以在usercontrol中找到
DropDownList

protected void BindActivities()
{
    foreach (string controlName in NoOfControls)
    {
        TimesheetUserControl  userControl = Timesheet.FindControl(controlName) as TimesheetUserControl;
        if(userControl == null) return;
        DropDownList dropActivities = userControl.FindControl("DropDownActivities") as DropDownList;
        if(dropActivities == null) return;
        DbConnection.Open();
        OleDbCommand cmd1 = new OleDbCommand("select designation from emp_master where username = '" + username + "'", DbConnection);
        OleDbDataAdapter da = new OleDbDataAdapter(Deptcmd);
        DataSet ds = new DataSet();
        da.Fill(ds);
        // DbConnection.Close();
        dropActivities.DataSource = ds;
        dropActivities.DataTextField = "ActivityName";
        dropActivities.DataBind();
        dropActivities.Items.Insert(0, new ListItem("--Select--", "0"));
    }
}

值在dropdownlist中绑定，但当我单击“添加新行”按钮时，行被添加，但在dropdownlist中值未绑定，请参见图像添加新用户控件时，需要重新绑定数据集。dropActivities.DataSource=ds；只有在未回发时才执行此操作。值在dropdownlist中绑定，但当我单击“添加新行”按钮时，行被添加，但在dropdownlist中值未绑定，请参见图像添加新用户控件时，需要重新绑定数据集。dropActivities.DataSource=ds；只有在未回发时才可以执行此操作。
protected void BindActivities()
{
    foreach (string controlName in NoOfControls)
    {
        TimesheetUserControl  userControl = Timesheet.FindControl(controlName) as TimesheetUserControl;
        if(userControl == null) return;
        DropDownList dropActivities = userControl.FindControl("DropDownActivities") as DropDownList;
        if(dropActivities == null) return;
        DbConnection.Open();
        OleDbCommand cmd1 = new OleDbCommand("select designation from emp_master where username = '" + username + "'", DbConnection);
        OleDbDataAdapter da = new OleDbDataAdapter(Deptcmd);
        DataSet ds = new DataSet();
        da.Fill(ds);
        // DbConnection.Close();
        dropActivities.DataSource = ds;
        dropActivities.DataTextField = "ActivityName";
        dropActivities.DataBind();
        dropActivities.Items.Insert(0, new ListItem("--Select--", "0"));
    }
}