Discuz下拉树形框控件

昨天发现简单的改进的下拉树形框控件,和大家一起分享

控件代码:

  1using System.Data;
  2using System.Web.UI;
  3using System.Web;
  4using System.Web.UI.WebControls;
  5using System.ComponentModel;
  6
  7using Discuz.Common;
  8using Discuz.Data;
  9
 10namespace Discuz.Control
 11{
 12    /**//// <summary>
 13    /// 下拉树形框控件。
 14    /// </summary>
 15    [DefaultProperty("Text"),ToolboxData("<{0}:DropDownTreeList runat=server></{0}:DropDownTreeList>")]
 16    public class DropDownTreeList : Discuz.Control.WebControl, IPostBackDataHandler, IPostBackEventHandler
 17    {
 18        /**//// <summary>
 19        /// 下拉列表框控件变量
 20        /// </summary>
 21        public System.Web.UI.WebControls.DropDownList TypeID=new System.Web.UI.WebControls.DropDownList();
 22    
 23
 24        /**//// <summary>
 25        /// 构造函数
 26        /// </summary>
 27        public DropDownTreeList(): base()
 28        {
 29            this.BorderStyle = BorderStyle.Groove; 
 30            this.BorderWidth=1; 
 31        }
 32
 33        /**//// <summary>
 34        /// 构造函数
 35        /// </summary>
 36        /// <param name="sqlstring">查询字符串</param>
 37        public DropDownTreeList(string sqlstring): this()
 38        {
 39             BuildTree(sqlstring);
 40        }
 41
 42        /**//// <summary>
 43        /// 构造函数
 44        /// </summary>
 45        /// <param name="sqlstring">查询字符串</param>
 46        /// <param name="selectid">选取项</param>
 47        public DropDownTreeList(string sqlstring,string selectid): this(sqlstring)
 48        {
 49            this.TypeID.SelectedValue=selectid;
 50        }
 51
 52        /**//// <summary>
 53        /// 创建树
 54        /// </summary>
 55        public void BuildTree()
 56        {
 57            if((this.SqlText!=null)&&(this.SqlText!=""))
 58            {
 59                BuildTree(this.SqlText);
 60            }
 61        }
 62
 63        /**//// <summary>
 64        /// 创建树
 65        /// </summary>
 66        /// <param name="sqlstring">查询字符串</param>
 67        public void BuildTree(string sqlstring)
 68        {
 69        
 70            string SelectedType="0";
 71            
 72            TypeID.SelectedValue=SelectedType;
 73
 74            this.Controls.Add(TypeID);
 75
 76            DataTable dt = DbHelper.ExecuteDataset(CommandType.Text, sqlstring).Tables[0];
 77
 78            TypeID.Items.Clear();
 79            //加载树
 80            TypeID.Items.Add(new ListItem("请选择     ","0"));
 81            DataRow [] drs = dt.Select(this.ParentID+"=0");    
 82        
 83            foreach( DataRow r in drs )
 84            {
 85                TypeID.Items.Add(new ListItem(r[1].ToString(),r[0].ToString()));
 86                string blank = HttpUtility.HtmlDecode("&nbsp;&nbsp;&nbsp;&nbsp;");
 87                BindNode( r[0].ToString() , dt,blank);
 88            }    
 89            TypeID.DataBind();            
 90
 91        }
 92
 93        /**//// <summary>
 94        /// 创建树
 95        /// </summary>
 96        /// <param name="sqlstring">查询字符串</param>
 97        /// <param name="selectid">选取项</param>
 98        public void BuildTree(string sqlstring,string selectid)
 99        {
            BuildTree(sqlstring);
            this.TypeID.SelectedValue=selectid;
        }

        /**//// <summary>
        /// 创建树结点
        /// </summary>
        /// <param name="sonparentid">当前数据项</param>
        /// <param name="dt">数据表</param>
        /// <param name="blank">空白符</param>
        private void BindNode(string sonparentid ,DataTable dt,string blank)
        {
            DataRow [] drs = dt.Select(this.ParentID+"=" + sonparentid );
            
            foreach( DataRow r in drs )
            {
                string nodevalue = r[0].ToString();                
                string text = r[1].ToString();                    
                text = blank + text;
                TypeID.Items.Add(new ListItem(text,nodevalue));
                string blankNode = HttpUtility.HtmlDecode("&nbsp;&nbsp;&nbsp;&nbsp;" + blank);
                BindNode(nodevalue,dt,blankNode);
            }
        }

        
        /**//// <summary>
        /// 选取项
        /// </summary>
        [Bindable(true),Browsable(true),Category("Appearance"),DefaultValue("")]
        public string SelectedValue
        {
            get
            {
                return this.TypeID.SelectedValue;
            }

            set
            {
                this.TypeID.SelectedValue = value;
            }
        }

        /**//// <summary>
        /// 父字段名称
        /// </summary>
        private string m_parentid="parentid";
        [Bindable(true),Category("Appearance"),DefaultValue("parentid")]
        public string ParentID
        {
            get
            {
                return m_parentid;
            }

            set
            {
                m_parentid = value;
            }
        }


        SQL字符串#region SQL字符串

        /**//// <summary>
        /// SQL字符串变量
        /// </summary>
        private string sqltext;


        /**//// <summary>
        /// SQL字符串属性
        /// </summary>
        [Bindable(true), Category("Appearance"), DefaultValue("")]
        public string SqlText
        {
            get
            {
                return sqltext;
            }

            set
            {
                sqltext = value;
            }
        }

        #endregion


        /**//// <summary>
        /// 当某选项被选中后,获取焦点的控件ID(如提交按钮等)
        /// </summary>
        [Bindable(true),Category("Appearance"),DefaultValue("")] 
        public string SetFocusButtonID
        {
            get
            {
                object o = ViewState[this.ClientID+"_SetFocusButtonID"];
                return (o==null)?"":o.ToString(); 
            }
            set
            {
                ViewState[this.ClientID+"_SetFocusButtonID"] = value;
                if(value!="")
                {
                    this.TypeID.Attributes.Add("onChange","document.getElementById('"+value+"').focus();");
                }
            }
        }

        /**//// <summary>
        /// 输出html,在浏览器中显示控件
        /// </summary>
        /// <param name="output"> 要写出到的 HTML 编写器 </param>
        protected override void Render(HtmlTextWriter output)
        {
            if (this.HintInfo != "")
            {
                output.WriteBeginTag("span id=\"" + this.ClientID + "\"  onmouseover=\"showhintinfo(this," + this.HintLeftOffSet + "," + this.HintTopOffSet + ",'" + this.HintTitle + "','" + this.HintInfo + "','" + this.HintHeight + "','" + this.HintShowType + "');\" onmouseout=\"hidehintinfo();\">");
            }

            RenderChildren(output);

            if (this.HintInfo != "")
            {
                output.WriteEndTag("span");
            }
        }



        IPostBackDataHandler 成员#region IPostBackDataHandler 成员

 
        /**//// <summary>
        /// 引发PostBackChanged事件
        /// </summary>
        public void RaisePostDataChangedEvent()
        {
        }


        /**//// <summary>
        /// 引发PostBack事件
        /// </summary>
        /// <param name="eventArgument"></param>
        public void RaisePostBackEvent(string eventArgument)
        {
        }

        /**//// <summary>
        /// 加载提交数据
        /// </summary>
        /// <param name="postDataKey"></param>
        /// <param name="postCollection"></param>
        /// <returns></returns>
        public bool LoadPostData(string postDataKey, System.Collections.Specialized.NameValueCollection postCollection)
        {

            string presentValue = this.TypeID.SelectedValue;
            string postedValue = postCollection[postDataKey];

            //如果回发数据不等于原有数据
            if (!presentValue.Equals(postedValue))
            {
                this.SqlText = postedValue;
                return true;
            }
            return false;

        }
        #endregion

    }
}

使用方法:

页面aspx代码:

<%@ Register TagPrefix="cc2" Namespace="Discuz.Control" Assembly="Discuz.Control" %>

<div id="showtargetforum" runat="server">

 <cc2:DropDownTreeList id="targetforumid" runat="server" Visible="true"></cc2:DropDownTreeList>

</div>

*.apsx.cs代码:  

  public void InitInfo()

        {
            #region 初始化信息绑定
            targetforumid.BuildTree(DatabaseProvider.GetInstance().GetForumsTree());
//绑定SQL语句
 if (DNTRequest.GetString("fid") != "")
            {
                targetforumid.SelectedValue = DNTRequest.GetString("fid");
                //addtype.SelectedValue = "1";
                targetforumid.Visible = true;
            }
  #endregion

}