asp.net 用户控件传值

aspx:

  private string _USID;

    public string USID
    {
        get { return _USID; }
        set { this.Label1.Text = value; }
    }

aspx

<%@ Register Src="uc.ascx" TagName="uc" TagPrefix="uc1" %>

 <uc1:uc ID="Uc1" runat="server" />

this.Uc1.USID = "aaa";
        this.Uc1.DataBind();