所选项目在回发时丢失（Sharepoint wss3.0 webpart）

Question

我是新的 Sharepoint 开发人员，尝试在窗口 Sharepoint 服务 3.0 [免费版] 中创建搜索 Web 部件，到目前为止，我可以从列表框中选择多个项目，但当我尝试将所选项目显示到文本框中时，它会丢失。

下面是我的代码：

using System;
using System.Runtime.InteropServices;
using System.Data;
using System.Collections.ObjectModel;
using System.Collections.Generic;
using System.ComponentModel;
using System.Text;
using System.Web;
using System.Drawing;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using Microsoft.SharePoint;
using Microsoft.SharePoint.Utilities;
using Microsoft.SharePoint.WebControls;
using Microsoft.SharePoint.WebPartPages;
using System.Xml.Serialization;
using System.Collections;


namespace Filter_WebPart  
{
    [Guid("6641a7a3-d2c4-4fda-9ef5-89596845bd6e")]

    public class Filter_WebPart : System.Web.UI.WebControls.WebParts.WebPart
    {
        protected DataSet _dataset;        
        protected ListBox lstRegion;
        protected ListBox lstMaterial;        
        protected HtmlButton btnSubmit;
        protected HtmlInputText txtDisplay;        

        private string myExceptions = "";                
        //private int[] Index1;


        protected override void CreateChildControls()
        {                                                
            try
            {                                                                
                //Region Table / DataSet
                lstRegion = new ListBox();                                

                lstRegion.ID="lstRegion";                
                lstRegion.SelectionMode = ListSelectionMode.Multiple;                                  
                //lstRegion.EnableViewState = true;                                
                //lstRegion.SelectedIndex = 0;                                


                //Material Table / DataSet
                lstMaterial = new ListBox();                
                lstMaterial.SelectionMode = ListSelectionMode.Multiple;                
                lstMaterial.EnableViewState = true;

                btnSubmit = new HtmlButton();                
                btnSubmit.InnerText = "Filter";                                                
                btnSubmit.ServerClick += new EventHandler(btnSubmit_Click);

                txtDisplay = new HtmlInputText();                                


                //CommandButton

                this.Controls.Add(lstRegion);
                this.Controls.Add(lstMaterial);
                this.Controls.Add(btnSubmit);
                this.Controls.Add(txtDisplay);               

            }
            catch(Exception ChildControlException)
            {
                myExceptions += "ChildControlException:" + ChildControlException.Message;
            }
            finally
            { 
                //base.CreateChildControls();
            }

        }        

        protected override void OnPreRender(EventArgs e)
        {            
           if(!this.Page.IsPostBack)
           {                
                lstMaterial.DataSource = GetMaterialList();
                lstMaterial.DataTextField = "Material Name";
                lstMaterial.DataValueField = "Material Name";
                lstMaterial.DataBind();                                                              

                lstRegion.DataSource = GetRegionList();                                
                lstRegion.DataTextField = "Region Name";
                lstRegion.DataValueField = "Region Name";
                lstRegion.DataBind();
                txtDisplay.Value="1 time";
            }
            base.OnPreRender(e);            
        }

        void btnSubmit_Click(object sender, EventArgs e)
        {                        
            string tmpStr="";                                   
            int k=0;    
            //int i=0; 


            lstMaterial.DataBind(); 
            lstRegion.DataBind();

            //int[] indx = lstRegion.GetSelectedIndices();
            //for(i=0;i<indx.Length;i++)
            //{
            //    tmpStr = tmpStr+","+lstRegion.Items[indx[i]].Text;
            //}


            //if(lstRegion.SelectedIndex >=0 )
            //{
               //for(i=0;i < lstRegion.Items.Count;i++)
               //{
               //    //if(i==5 || i==10)
               //    //{
               //    //    lstRegion.Items[i].Selected = true;
               //    //}
               //    if(lstRegion.Items[i].Selected)
               //    {
               //        tmpStr = lstRegion.Items[i].Text;                       
               //    }
               //    k=k+1;
               //}
            //}

            foreach(ListItem RgItem in lstRegion.Items)
            {                                    
                if(RgItem.Selected == true)
                {                                                
                    tmpStr = tmpStr +","+RgItem.Text;                    
                    k=k+1;
                }                                
            }                

            //for(i=0;i<lstRegion.Items.Count;i++)
            //{
            //    if(lstRegion.Items[i].Selected == true)
            //    {
            //        txtDisplay.Value = txtDisplay.Value +","+lstRegion.Items[i].Text;     
            //        k=k+1;
            //    }                
            //}

            if(tmpStr != "" )
            {txtDisplay.Value = tmpStr;}
            else{                                   
                txtDisplay.Value = k.ToString();
                btnSubmit.InnerText = "Done";} 


        }                


        protected override void OnInit(EventArgs e)
        {                               
            base.OnInit(e);
            EnsureChildControls();                                                     
        }

        private DataSet GetRegionList()
        {            
            _dataset = new DataSet();
            DataTable _tbl = new DataTable();
            DataColumn _tblcol = new DataColumn("Region Name");
            _tbl.Columns.Add(_tblcol);            

            SPWeb web = SPContext.Current.Site.RootWeb;
            SPList myList = web.Lists["Service Area"];
            SPQuery query = new SPQuery();
            query.Query = "";
            SPListItemCollection items = myList.GetItems(query);

                foreach (SPListItem item in items)
                {
                    DataRow _row = _tbl.NewRow();                     
                    _row[0] = SPEncode.HtmlEncode(item["Region Name"].ToString());
                    _tbl.Rows.Add(_row);
                }

            _dataset.Tables.Add(_tbl);
            return _dataset;
        }

        private DataSet GetMaterialList()
        {
            _dataset = new DataSet();
            DataTable _tbl = new DataTable();
            DataColumn _tblcol = new DataColumn("Material Name");
            _tbl.Columns.Add(_tblcol);
            SPWeb web = SPContext.Current.Site.RootWeb;

                SPList myList = web.Lists["Material Master"];
                SPQuery query = new SPQuery();
                query.Query = "";
                SPListItemCollection items = myList.GetItems(query);
                foreach (SPListItem item in items)
                {
                    DataRow _row = _tbl.NewRow();
                    _row[0] = SPEncode.HtmlEncode(item["Material Name"].ToString());
                    _tbl.Rows.Add(_row);
                }

            _dataset.Tables.Add(_tbl);
            return _dataset;            
        }

        protected override void RenderContents(HtmlTextWriter output)
        {
            try
            {                
                this.EnsureChildControls();
                lstRegion.RenderControl(output);
                lstMaterial.RenderControl(output);
                btnSubmit.RenderControl(output);
                output.Write("<br>");
                txtDisplay.RenderControl(output);     

                //base.RenderContents(output);
            }
            catch (Exception RenderContentsException)
            {
                myExceptions += "RenderException:" + RenderContentsException.Message;
            }
            finally
            {
                if (myExceptions.Length > 0)
                {
                    output.WriteLine(myExceptions);
                }
            }
        }


    }
}

Answer 1

这应该有效。我已经在我的 2010 年农场上尝试过你的代码，它工作正常（也应该适用于 WSS3）。

您是否在更新程序集后忘记执行 iisreset ？

找到解决方案的最佳机会是使用调试器。您可以将调试器附加到正确的 w3wp.exe 进程。如果您不知道哪一个，请全部选择。然后在事件处理程序上设置断点并检查丢失选择的位置。

您不需要覆盖OnInit，您可以将EnsureChildControls()放在btnSubmit_Click中。