关于 DropDownList 赋值的问题

<%@ Page Language="C#" MasterPageFile="~/MasterPage.master" AutoEventWireup="true" CodeFile="DepartmentView.aspx.cs" Inherits="DepartmentView" Debug="true" %>
<asp:Content ID="Content1" ContentPlaceHolderID="ContentPlaceHolder1" Runat="Server">
        <div class="c_MainLeft">
<ul style="text-align:left;">
    <li style="list-style-type: none;height:120px;">
        <img src="images/045.png" /></li><li style="list-style-type: none;height:40px;"></li>
    <li style="list-style-type: none;height:40px;">共有 <asp:Label ID="lbl_Count" runat="server"
        Style="color: red"></asp:Label>  个部门</li><li style="list-style-type: none;height:40px;"></li>
    </ul>
        </div>
        <div class="c_MainRight">
            <asp:Panel ID="pDepartmentMenu3" runat="server" CssClass="c_Menu3">
                <asp:LinkButton ID="lbDepartmentAdd" runat="server" OnClick="lbDepartmentAdd_Click" CssClass="c_Menu3Button">新增</asp:LinkButton>
                <asp:LinkButton ID="lbDepartmentEdit" runat="server" OnClick="lbDepartmentEdit_Click" CssClass="c_Menu3Button">修改</asp:LinkButton></asp:Panel>
            <asp:GridView ID="GV_Department" runat="server" AutoGenerateColumns="False" CellPadding="4"
                ForeColor="#333333" Style="width: 100%" OnRowCancelingEdit="GV_Department_RowCancelingEdit" OnRowDeleting="GV_Department_RowDeleting" OnSelectedIndexChanging="GV_Department_SelectedIndexChanging">
                <FooterStyle BackColor="#507CD1" Font-Bold="True" ForeColor="White" />
                <Columns>
                     <asp:BoundField DataField="id" HeaderText="部门代码">
<ItemStyle HorizontalAlign="Center" />
                        <HeaderStyle Width="10%" />
                    </asp:BoundField>
                     <asp:BoundField DataField="name" HeaderText="部门名称">
                        <ItemStyle HorizontalAlign="Center" />
                        <HeaderStyle Width="15%" />
                    </asp:BoundField>
                     <asp:BoundField DataField="create_name" HeaderText="创建用户">
                        <ItemStyle HorizontalAlign="Center" />
                        <HeaderStyle Width="12%" />
                    </asp:BoundField>
                     <asp:BoundField DataField="update_name" HeaderText="更新用户">
                        <ItemStyle HorizontalAlign="Center" />
                        <HeaderStyle Width="12%" />
                    </asp:BoundField>
                     <asp:BoundField DataField="create_date" HeaderText="创建日期">
                        <ItemStyle HorizontalAlign="Center" />
                        <HeaderStyle Width="12%" />
                    </asp:BoundField>
                     <asp:BoundField DataField="update_date" HeaderText="更新日期">
                        <ItemStyle HorizontalAlign="Center" />
                        <HeaderStyle Width="12%" />
                    </asp:BoundField>
                      <asp:TemplateField HeaderText="有效标志">
  <ItemTemplate>
  <asp:DropDownList ID="ddl1" runat="server" Visible="true" width = "100%">
  </asp:DropDownList>   
  </ItemTemplate>
</asp:TemplateField>                    <asp:CommandField HeaderText="选择" ShowSelectButton="True">
                        <HeaderStyle Width="8%" />
                        <ItemStyle HorizontalAlign="Center" />
                    </asp:CommandField>
                    <asp:TemplateField HeaderText="删除" ShowHeader="False">
                        <ItemStyle HorizontalAlign="Center" />
                        <HeaderStyle Width="8%" />
                        <ItemTemplate>
                            <asp:LinkButton ID="LinkButton1" runat="server" CausesValidation="False" CommandName="Delete"
                                OnClientClick='return confirm("确认要删除吗？")' Text="删除"></asp:LinkButton>
                        </ItemTemplate>
                    </asp:TemplateField>
                </Columns>
                <RowStyle BackColor="#EFF3FB" />
                <EditRowStyle BackColor="#2461BF" />
                <SelectedRowStyle BackColor="#D1DDF1" Font-Bold="True" ForeColor="#333333" />
                <PagerStyle BackColor="#2461BF" ForeColor="White" HorizontalAlign="Center" />
                <HeaderStyle BackColor="#507CD1" Font-Bold="True" ForeColor="White" />
                <AlternatingRowStyle BackColor="White" />
            </asp:GridView>
        </div>
</asp:Content>将有效标志位 绑定为 DropDownList ddl （红色部分） 可编译后 显示 编译错误 
说明: 在编译向该请求提供服务所需资源的过程中出现错误。请检查下列特定错误详细信息并适当地修改源代码。 编译器错误消息: CS0165: 使用了未赋值的局部变量“ddl”源错误: 行 27:  SignDropDownList sign = new SignDropDownList();
行 28:  DataSet ds_Sign = sign.GetDataSet("");
行 29:       ddl.DataSource = ds_Sign;
行 30:  ddl.DataValueField = "id";
行 31:  ddl.DataTextField = "name";
 源文件: e:\soft\HR\DepartmentView.aspx.cs    行: 29 请问 这个问题是哪里出错了 该如何修改 谢谢

解决方案 »

  1.   

    cs 文件 如下 using System;
    using System.Data;
    using System.Data.SqlClient;
    using System.Configuration;
    using System.Collections;
    using System.Web;
    using System.Web.Security;
    using System.Web.UI;
    using System.Web.UI.WebControls;
    using System.Web.UI.WebControls.WebParts;
    using System.Web.UI.HtmlControls;public partial class DepartmentView : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            DropDownList ddl;
    if (!Page.IsPostBack)
            {
                Department department = new Department();
                DataSet ds_Department = department.GetDataSet("");
    //GV_Department.DataSource = ds_Department.Tables["T_Department"];
        GV_Department.DataSource = ds_Department.Tables["hr.dbo.v_hr_bm"];
                GV_Department.DataBind();
                //lbl_Count.Text = ds_Department.Tables["T_Department"].Rows.Count.ToString();
        lbl_Count.Text = ds_Department.Tables["hr.dbo.v_hr_bm"].Rows.Count.ToString();
    SignDropDownList sign = new SignDropDownList();
    DataSet ds_Sign = sign.GetDataSet("");
          ddl.DataSource = ds_Sign;
    ddl.DataValueField = "id";
    ddl.DataTextField = "name";
    ddl.DataBind(); 
    }
            if (Request.Cookies["Rank_Code"] != null)
            {
                publicFunction pFunction = new publicFunction();
                String strRankCode = Request.Cookies["Rank_Code"].Value;
                String strFunctionCode = "Department";
                String strReturn = pFunction.GetPurview(strRankCode, strFunctionCode);
                if (strReturn.Contains("fail"))
                    Response.Redirect("PurviewError.aspx");
            }
        }
        protected void GV_Department_SelectedIndexChanging(object sender, GridViewSelectEventArgs e)
        {
            int Int_SelectIndex = e.NewSelectedIndex;        Response.Cookies["RowIndex"].Value = Int_SelectIndex.ToString();        Department department = new Department();
            DataSet ds_Department = department.GetDataSet("");
            GV_Department.DataSource = ds_Department.Tables["T_Department"];
            GV_Department.DataBind();
        }
        protected void GV_Department_RowCancelingEdit(object sender, GridViewCancelEditEventArgs e)
        {
            int Int_RowIndex = -1;
            GV_Department.EditIndex = Int_RowIndex;        Department department = new Department();
            DataSet ds_Department = department.GetDataSet("");
            GV_Department.DataSource = ds_Department.Tables["T_Department"];
            GV_Department.DataBind();
        }
        protected void GV_Department_RowDeleting(object sender, GridViewDeleteEventArgs e)
        {
            int Int_RowIndex = e.RowIndex;        Department department = new Department();        //删除部门
            department.RowIndex = Int_RowIndex;
            String strReturn = department.DepartmentDelete();
            if (strReturn.Contains("ok"))
            {
                //获取新的部门信息列表
                DataSet ds_Department = new DataSet();
                ds_Department = department.GetDataSet("");
                GV_Department.DataSource = ds_Department.Tables["T_Department"];
                GV_Department.DataBind();
            }
            else if (strReturn.Contains("fail"))
            {
                Response.Write(strReturn.Replace("fail", ""));
            }
        }
        protected void lbDepartmentAdd_Click(object sender, EventArgs e)
        {
            Response.Redirect("DepartmentEdit.aspx?Command=INSERT");
        }
        protected void lbDepartmentEdit_Click(object sender, EventArgs e)
        {
            //GridView GV_Department = (GridView)this.Parent.Controls[3].Controls[1];
            Response.Redirect("DepartmentEdit.aspx?Command=UPDATE&RowIndex=" + GV_Department.SelectedIndex.ToString());
        }
    }
      

  2.   

    ddl没有被初始化。
    检查你的 .designer.cs
      

  3.   

     //遍历GridView 利用FindControl()先找到DropDownList 
       
       DropDownList   ddl= GV_Department.Rows[i].FindControl("ddl1") as DropDownList;  
      

  4.   


    因为服务器不知道你那个 ddl 是什么 
      

  5.   

    SignDropDownList.cs 文件如下using System;
    using System.Data;
    using System.Data.SqlClient;
    using System.Collections;
    using System.Configuration;
    using System.Web;
    using System.Web.Security;
    using System.Web.UI;
    using System.Web.UI.WebControls;
    using System.Web.UI.WebControls.WebParts;
    using System.Web.UI.HtmlControls;/// <summary>
    /// Department 的摘要说明
    /// </summary>
    public class SignDropDownList
    {
    public SignDropDownList()
    {
    //
    // TODO: 在此处添加构造函数逻辑
    //
        }    private String Sign_id;
        private String Sign_name;
        private int intRowIndex;    #region 属性代码
        
        public String Field_Sign_id
        {
            get
            {
                return Sign_id;
            }
            set
            {
                Sign_id = value;
            }
        }    public String Field_Sign_name
        {
            get
            {
                return Sign_name;
            }
            set
            {
                Sign_name = value;
            }
        }    public int RowIndex
        {
            get
            {
                return intRowIndex;
            }
            set
            {
                intRowIndex = value;
            }
        }
        #endregion    //返回符合条件的数据集
        public DataSet GetDataSet(String strQuery)
        {
            ConnectionStringSettingsCollection connectionStrings = ConfigurationManager.ConnectionStrings;        //得到连接字符串
            String strConn = connectionStrings["strConn"].ConnectionString;        String strSQL = "";   strSQL = "Select id,name From hr.dbo.hr_bz";
      
            //连接数据库
            SqlConnection connMain = new SqlConnection(strConn);
            connMain.Open();        DataSet ds_Sign = new DataSet();
            SqlDataAdapter dr_Sign = new SqlDataAdapter(strSQL, connMain);        dr_Sign.Fill(ds_Sign, "hr.dbo.hr_bz");        //生成Sing数据表的主键
            ds_Sign.Tables["hr.dbo.hr_bz"].PrimaryKey = new DataColumn[] { ds_Sign.Tables["hr.dbo.hr_bz"].Columns["id"] };        return ds_Sign;
        }
        //返回符合条件的DataReader
        public SqlDataReader GetDataReader(String strQuery)
        {
            ConnectionStringSettingsCollection connectionStrings = ConfigurationManager.ConnectionStrings;        //得到连接字符串
            String strConn = connectionStrings["strConn"].ConnectionString;        String strSQL = ""; 
       strSQL = "Select id,name From hr.dbo.hr_bz";
            //连接数据库
            SqlConnection connMain = new SqlConnection(strConn);
            connMain.Open();        SqlCommand cmd_Department = new SqlCommand(strSQL, connMain);
            SqlDataReader SDR_Department = cmd_Department.ExecuteReader();        return SDR_Department;
        }
        //插入新行
        public String DepartmentInsert()
        {
            ConnectionStringSettingsCollection connectionStrings = ConfigurationManager.ConnectionStrings;
    /*
            //得到连接字符串
            String strConn = connectionStrings["strConn"].ConnectionString;        String strSQL = "INSERT INTO T_Department (";
            strSQL += "Department_Code,";
            strSQL += "Department_Name";
            strSQL += ") VALUES (";
            strSQL += "'" + Department_Code + "',";
            strSQL += "'" + Department_Name + "')";
            //连接数据库
            SqlConnection connMain = new SqlConnection(strConn);
            connMain.Open();        SqlCommand cmdDepartment = new SqlCommand(strSQL, connMain);
            int intReturn = cmdDepartment.ExecuteNonQuery();        return "ok";
        */return "OK";
    }
        //更新记录 
        public String DepartmentUpdate()
        {
        /*  
    try
            {
                ConnectionStringSettingsCollection connectionStrings = ConfigurationManager.ConnectionStrings;            //得到连接字符串
                String strConn = connectionStrings["strConn"].ConnectionString;            //连接数据库
                SqlConnection connMain = new SqlConnection(strConn);
                connMain.Open();            String strSQL = "Select * From T_Department";            DataSet ds_Department = new DataSet();
                SqlDataAdapter dr_Department = new SqlDataAdapter();
                SqlCommandBuilder CB_Department = new SqlCommandBuilder(dr_Department);
                dr_Department.SelectCommand = new SqlCommand(strSQL, connMain);
                dr_Department.UpdateCommand = CB_Department.GetUpdateCommand(true);            dr_Department.Fill(ds_Department, "T_Department");  //填充T_Department信息表            //生成T_Department数据表的主键
                ds_Department.Tables["T_Department"].PrimaryKey = new DataColumn[] { ds_Department.Tables["T_Department"].Columns["Department_ID"] };            DataRow DR_Department = ds_Department.Tables["T_Department"].Rows[intRowIndex];            DR_Department["Department_Code"] = Department_Code;
                DR_Department["Department_Name"] = Department_Name;            dr_Department.Update(ds_Department.Tables["T_Department"]);    //把更新的信息发送到数据库            ds_Department.AcceptChanges();            return "ok" + Department_Name;
            }
            catch (Exception ex)
            {
                return "fail" + intRowIndex.ToString() + "/" + ex.ToString();
            }
        */ return "OK";
    }
        //删除行
        public String DepartmentDelete()
        {
    /*
            try
            {
                ConnectionStringSettingsCollection connectionStrings = ConfigurationManager.ConnectionStrings;            //得到连接字符串
                String strConn = connectionStrings["strConn"].ConnectionString;            //连接数据库
                SqlConnection connMain = new SqlConnection(strConn);
                connMain.Open();            String strSQL = "Select * From T_Department";            DataSet ds_Department = new DataSet();
                SqlDataAdapter dr_Department = new SqlDataAdapter();
                SqlCommandBuilder CB_Department = new SqlCommandBuilder(dr_Department);
                dr_Department.SelectCommand = new SqlCommand(strSQL, connMain);
                dr_Department.DeleteCommand = CB_Department.GetDeleteCommand(true);            dr_Department.Fill(ds_Department, "T_Department");  //填充T_Department信息表            //生成T_Department数据表的主键
                ds_Department.Tables["T_Department"].PrimaryKey = new DataColumn[] { ds_Department.Tables["T_Department"].Columns["Department_ID"] };            ds_Department.Tables["T_Department"].Rows[intRowIndex].Delete();            dr_Department.Update(ds_Department.Tables["T_Department"]);            ds_Department.AcceptChanges();            return "ok";
            }
            catch (Exception ex)
            {
                return "fail" + intRowIndex.ToString() + "/" + ex.ToString();
            }
        */return "OK";
    }
    }
    问下  //遍历GridView 利用FindControl()先找到DropDownList  
        
      DropDownList ddl= GV_Department.Rows[i].FindControl("ddl1") as DropDownList;这个应该 放在 上面 3个文件的那个文件的 那个位置 是最恰当的  最好能帮我分析下这3个文件的作用 和 拆分原则 谢谢 ！ 第一次 学 很白 
      

  6.   

    我晕，嵌套到gridveiw的控件不能直接调用。遍历findconreol后自再使用
      

  7.   

    DropDownList dp=(DropDownList)gridview1.Rows[0].FinControl("ddl1");
    dp.datasource=....