请教关于在GridView编辑中添加DropDownlist的问题

Question

我想在GirdView控件的编辑功能中，把由TextBox输入换成DropDownlist从数据库取出的值。实现如下，GridView控件绑定AccessDataSourc1，选取Class表中的所有列。DropDownlist控件绑定AccessDataSourc2，选取Product表中的ProName列（注：已将要由Dropdownlist选取的列转化为模板列），可是在Dropdownlist的SelectedValue中只能选取AccessDataSourc1中Class表的列，明明Dropdownlist绑定的是AccessDataSourc2 Product表中的ProName列。

Answer 1

状态保持的问题itemdatabound一个一个设置

Answer 2

不防参考参考:http://blog.csdn.net/insus/archive/2008/03/26/2221260.aspx

Answer 3

<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" DataKeyNames="ID"
            DataSourceID="AccessDataSource1"  CellPadding="4" ForeColor="#333333" GridLines="None" OnRowUpdating="GridView1_RowUpdating">
            <Columns>
                <asp:TemplateField HeaderText="采购物品" SortExpression="Content">
                    <EditItemTemplate>
                        <asp:DropDownList ID="DropDownList1" runat="server"
                            DataTextField="PurchaseName" DataValueField="PurchaseName" DataSourceID="AccessDataSource2" 
                         >
                        </asp:DropDownList>
                        <asp:AccessDataSource ID="AccessDataSource2" runat="server" DataFile="~/App_Data/#Date.mdb"
                            SelectCommand="SELECT [PurchaseName] FROM [Item]" ></asp:AccessDataSource>                    </EditItemTemplate>
                    <ItemTemplate>
                        <asp:Label ID="Label2" runat="server" Text='<%# Bind("Content") %>'></asp:Label>
                    </ItemTemplate>
                    <ItemStyle Width="160px" />
                </asp:TemplateField>
                <asp:BoundField DataField="Type" HeaderText="型号" SortExpression="Type">
                    <ItemStyle Width="160px" />
                </asp:BoundField>
                <asp:BoundField DataField="Notice" HeaderText="备注" SortExpression="Notice">
                    <ItemStyle Width="160px" />
                </asp:BoundField>
                <asp:BoundField DataField="RefPrice" HeaderText="参考价格" SortExpression="RefPrice">
                    <ItemStyle Width="160px" />
                </asp:BoundField>
                <asp:TemplateField HeaderText="数量" SortExpression="Number">
                    <EditItemTemplate>
                        <asp:TextBox ID="NumberReq" runat="server" Text='<%# Bind("Number") %>' Columns="10"></asp:TextBox>
                        <asp:RangeValidator ID="RangeValidator1" runat="server" ControlToValidate="NumberReq"
                            ErrorMessage="*" MaximumValue="9999" MinimumValue="1"></asp:RangeValidator>
                        <asp:RequiredFieldValidator ID="RequiredFieldValidator1" runat="server" ErrorMessage="*" ControlToValidate="NumberReq"
                            ></asp:RequiredFieldValidator>                    </EditItemTemplate>
                    <ItemTemplate>
                        <asp:Label ID="Label1" runat="server" Text='<%# Bind("Number") %>'></asp:Label>
                    </ItemTemplate>
                    <ItemStyle Width="160px" />
                </asp:TemplateField>
                <asp:TemplateField HeaderText="操作" ShowHeader="False">
                    <EditItemTemplate>
                        <asp:Button ID="Button11" runat="server" CausesValidation="True" CommandName="Update"
                            Text="更新" />&nbsp;<asp:Button ID="Button2" runat="server" CausesValidation="False"
                                CommandName="Cancel" Text="取消" />
                    </EditItemTemplate>
                    <ItemTemplate>
                        <asp:Button ID="Button2" runat="server" CausesValidation="False" CommandName="Edit"
                            Text="编辑" />&nbsp;<asp:Button ID="Button3" runat="server" CausesValidation="False"
                                CommandName="Delete" Text="删除"  OnClientClick="return confirm('确认要删除吗？')"/>
                    </ItemTemplate>
                </asp:TemplateField>
                <asp:TemplateField ShowHeader="False">
                    <ItemTemplate>
                        <asp:Button ID="Button1" runat="server" CausesValidation="false" CommandName="Insert"
                            Text="新建" OnClick="Button1_Click1"/>
                    </ItemTemplate>
                </asp:TemplateField>
            </Columns>
            <EmptyDataTemplate>            </EmptyDataTemplate>
            <FooterStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" />
            <RowStyle BackColor="#F7F6F3" ForeColor="#333333" HorizontalAlign="Center" VerticalAlign="Middle" />
            <PagerStyle BackColor="#284775" ForeColor="White" HorizontalAlign="Center" />
            <SelectedRowStyle BackColor="#E2DED6" Font-Bold="True" ForeColor="#333333" />
            <HeaderStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" />
            <EditRowStyle BackColor="#999999" />
            <AlternatingRowStyle BackColor="White" ForeColor="#284775" />
        </asp:GridView>
        <asp:AccessDataSource ID="AccessDataSource1" runat="server" DataFile="~/App_Data/#Date.mdb"
            DeleteCommand="DELETE FROM [PurchaseContent] WHERE [ID] = ?" InsertCommand="INSERT INTO [PurchaseContent] ([Content], [Type], [Notice], [RefPrice], [Number]) VALUES (?, ?, ?, ?, ?)"
            SelectCommand="SELECT * FROM [PurchaseContent]" UpdateCommand="UPDATE [PurchaseContent] SET [Content] = ?, [Type] = ?, [Notice] = ?, [RefPrice] = ?, [Number] = ? WHERE [ID] = ?">
            <DeleteParameters>
                <asp:Parameter Name="ID" Type="Int32" />
            </DeleteParameters>
            <UpdateParameters>
                <asp:Parameter Name="Content" Type="String" />
                <asp:Parameter Name="Type" Type="String" />
                <asp:Parameter Name="Notice" Type="String" />
                <asp:Parameter Name="RefPrice" Type="String" />
                <asp:Parameter Name="Number" Type="Int32" />
                <asp:Parameter Name="ID" Type="Int32" />
            </UpdateParameters>
            <InsertParameters>
                <asp:Parameter Name="Content" Type="String" />
                <asp:Parameter Name="Type" Type="String" />
                <asp:Parameter Name="Notice" Type="String" />
                <asp:Parameter Name="RefPrice" Type="String" />
                <asp:Parameter Name="Number" Type="Int32" />
            </InsertParameters>
        </asp:AccessDataSource>Dropdownlist 的SelectedValue中只能选取AccessDataSourc1的列

Answer 4

你的AccessDataSource1应该把对应的id查询出来，这样你的代码应该是<asp:DropDownList ID="DropDownList1" runat="server" DataTextField="PurchaseName" DataValueField="PurchaseName" DataSourceID="AccessDataSource2"></asp:DropDownList> 
==
<asp:DropDownList ID="DropDownList1" runat="server" DataTextField="PurchaseName" DataValueField="PurchaseID" DataSourceID="AccessDataSource2" SelectedValue='<%# Eval("PurchaseID")%>'></asp:DropDownList> 

Answer 5

两种方法：
第一：你可以一个一个用foreach遍历上去。
第二：写个存储过程。将结果集一次加进去。请楼下补充

Answer 6

2楼给的视频看完了，没有给OnRowUpdating事件的代码。我可能没表述清楚我的问题。重新说下。
1）是否在前台DropDownlist代码中加入SelectedValue=<%# bind("PurchaseName")就可以自动更新数据（这样做会有错误提示，说PurchaseName不是SelectedValue的属性，也就是我本贴问的问题），后台不用添加任何代码呢？
2）如果需要在后台添加OnRowUpdating事件代码，请给下，谢谢。

Answer 7

1）是否在前台DropDownlist代码中加入SelectedValue= <%# bind("PurchaseName")就可以自动更新数据（这样做会有错误提示，说PurchaseName不是SelectedValue的属性，也就是我本贴问的问题），后台不用添加任何代码呢？ 
==
对的，前提是你使用SqlDataSource控件SelectedValue= '<%# Bind("PurchaseName") %>'

Answer 8

你是想用Item表的选项来更新PurchaseContent表的Content字段是吧？这里有个问题，因为使用了Bind()双向绑定。如果要编辑的PurchaseContent表某一行的Content字段的值没法和Item表中的数据对应上，那就会出现错误！所以一般这种情况从数据库设计时就应该让Content字段成为外键，也就是存Item表的ID（如int)，而不是实际的值。这种情况下利用DropDownList才叫合理。1、把PurchaseContent的Content字段数据类型改成与Item表的ID一样，比如int.
2、你可以把AccessDataSourc2的SelectCommand改成："SELECT [ID], [PurchaseName] FROM [Item]" 
3、改DropDownList的DataValueField
<asp:DropDownList ID="DropDownList1" runat="server" 
                            DataTextField="PurchaseName" DataValueField="ID" DataSourceID="AccessDataSource2" 
   >这样PurchaseContent的Content字段会存对应的ID，将来如果想用GridView之类的控件显示时，你可以把DataSource控件的SelectCommand写成：
SELECT PurchaseContent.ID, Type, Notice, RefPrice, Number, Release, (select Content from Item where Item.ID=PurchaseContent.Content) as Content from PurchaseContent

Answer 9

对了，DropDownList里还得加一个Bind
<asp:DropDownList ID="DropDownList1" runat="server" 
    DataTextField="PurchaseName" DataValueField="ID" DataSourceID="AccessDataSource2"  SelectedValue='<%# Bind("Content") %>'
  > 

Answer 10

这个问题的例子 有很多 
可以参照下事例
自己学习下..地址:
http://blog.csdn.net/insus/archive/2008/03/26/2221260.aspx

Answer 11

综合大家的意见，代码如下。可以得到DropDownList的SelectedValue了。但是不知道怎么更新数据库，怎么才能获得要更换新的行的ID呢？
    protected void GridView1_RowUpdating(object sender, GridViewUpdateEventArgs e)
    {
     
            DropDownList ddl = GridView1.Rows[e.RowIndex].FindControl("DropDownlist1") as DropDownList;
            if (ddl != null)
            {
               string Name = ddl.SelectedValue;
               OleDbConnection conn = new OleDbConnection(@"Provider=Microsoft.Jet.OLEDB.4.0; Data Source=" + HttpContext.Current.Server.MapPath("~/App_Data/#date.mdb"));
               conn.Open();
               OleDbCommand cmd = new OleDbCommand("UPDATE PurchaseContent SET Content='" + Name + "' WHERE ID = @ID", conn);
               OleDbParameter parm1 = new OleDbParameter("@ID", SqlDbType.Int);
               parm1.Value =GridView1.DataKeys         //这行不会写了，怎么才能获得ID？？？？
               cmd.Parameters.Add(parm1);
               cmd.ExecuteNonQuery();
               conn.Close();
            }
    }

Answer 12

其实在用DataSource控件的情况下，在GridView_RowUpdating或DataSource_Updating里写更新数据库这种作法都是‘错误’的。如果都照这么个写法，那要DataSource控件干吗呢！

Answer 13

终于搞定了，数据绑定的代码如下：    protected void GridView1_RowUpdating(object sender, GridViewUpdateEventArgs e)
    {
     
            DropDownList ddl = GridView1.Rows[e.RowIndex].FindControl("DropDownlist1") as DropDownList;
            if (ddl != null)
            {
               string Name = ddl.SelectedValue;
               OleDbConnection conn = new OleDbConnection(@"Provider=Microsoft.Jet.OLEDB.4.0; Data Source=" + HttpContext.Current.Server.MapPath("~/App_Data/#date.mdb"));
               if (conn.State == ConnectionState.Closed)
               {
                   conn.Open();
               }
               int ID = (int)GridView1.DataKeys[e.RowIndex].Value;
               string sql = "UPDATE PurchaseContent SET Content =" +Name+" WHERE ID = " + ID;
               OleDbCommand cmd = new OleDbCommand(sql, conn);
               cmd.ExecuteNonQuery();
               conn.Close();
               GridView1.EditIndex = -1;
               Label3.Text = sql;
            }
    }至此，Gridview在编辑模板中添加DropdownList，并更新数据库完成。谢谢各位老师，回答都有分

Answer 14

GridViewUp.aspx.cs文件代码：
using System;
using System.Data;
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;
using System.Data.SqlClient;public partial class gridview_GridViewUp : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            GridViewBind();
        }
    }    protected void GridView1_PageIndexChanging(object sender, GridViewPageEventArgs e)
    {
        GridView1.PageIndex = e.NewPageIndex;
        GridViewBind();
    }    private void GridViewBind()
    {
        string connStr = ConfigurationManager.ConnectionStrings["ConnString"].ConnectionString;
        string SqlStr = "Select a.*,b.description FROM test01 a,xueli b where a.xueli=b.code and a.id<1000 and a.id>200";
        DataSet ds = new DataSet();        try
        {
            SqlConnection conn = new SqlConnection(connStr);
            if (conn.State.ToString() == "Closed") conn.Open();
            SqlDataAdapter da = new SqlDataAdapter(SqlStr, conn);
            da.Fill(ds, "test01");
            if (conn.State.ToString() == "Open") conn.Close();            GridView1.DataSource = ds.Tables[0].DefaultView;
            GridView1.DataBind();
        }
        catch (Exception ex)
        {
            Response.Write("数据库错误，错误原因：" + ex.Message);
            Response.End();
        }
    }    protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
    {
        if (((DropDownList)e.Row.FindControl("DDLXueli")) != null)
        {        
            DropDownList ddlxueli = (DropDownList)e.Row.FindControl("DDLXueli");            // 生成 DropDownList 的值，绑定数据
            string connStr = ConfigurationManager.ConnectionStrings["ConnString"].ConnectionString;
            string SqlStr = "Select * from xueli";
            DataSet ds = new DataSet();            SqlConnection conn = new SqlConnection(connStr);
            if (conn.State.ToString() == "Closed") conn.Open();
            SqlDataAdapter da = new SqlDataAdapter(SqlStr, conn);
            da.Fill(ds, "xueli");
            if (conn.State.ToString() == "Open") conn.Close();            ddlxueli.DataSource = ds.Tables[0].DefaultView;
            ddlxueli.DataTextField = "description";
            ddlxueli.DataValueField = "code";
            ddlxueli.DataBind();
            //            // 选中 DropDownList
            ddlxueli.SelectedValue = ((HiddenField)e.Row.FindControl("HDFXueli")).Value;
            //
        }
    }    protected void GridView1_RowEditing(object sender, GridViewEditEventArgs e)
    {
        GridView1.EditIndex = e.NewEditIndex;
        GridViewBind();
    }
    protected void GridView1_RowCancelingEdit(object sender, GridViewCancelEditEventArgs e)
    {
        GridView1.EditIndex = -1;
        GridViewBind();
    }    protected void GridView1_RowUpdating(object sender, GridViewUpdateEventArgs e)
    {
        string id = GridView1.DataKeys[e.RowIndex].Values[0].ToString();
        string card = ((TextBox)GridView1.Rows[e.RowIndex].FindControl("TBCard")).Text;
        string xueli = ((DropDownList)GridView1.Rows[e.RowIndex].FindControl("DDLXueli")).SelectedValue;
        string price = ((TextBox)GridView1.Rows[e.RowIndex].FindControl("TBPrice")).Text;        string connStr = ConfigurationManager.ConnectionStrings["ConnString"].ConnectionString;
        string SqlStr = "update test01 set card='" + card + "',xueli='" + xueli + "',price='" + price + "' where id=" + id;        try
        {
            SqlConnection conn = new SqlConnection(connStr);
            if (conn.State.ToString() == "Closed") conn.Open();
            SqlCommand comm = new SqlCommand(SqlStr, conn);
            comm.ExecuteNonQuery();
            comm.Dispose();
            if (conn.State.ToString() == "Open") conn.Close();            GridView1.EditIndex = -1;
            GridViewBind();
        }
        catch (Exception ex)
        {
            Response.Write("数据库错误，错误原因：" + ex.Message);
            Response.End();
        }
    }    protected void GridView1_RowDeleting(object sender, GridViewDeleteEventArgs e)
    {
        string id = GridView1.DataKeys[e.RowIndex].Values[0].ToString();
        string connStr = ConfigurationManager.ConnectionStrings["ConnString"].ConnectionString;
        string SqlStr = "delete from test01 where id=" + id;        try
        {
            SqlConnection conn = new SqlConnection(connStr);
            if (conn.State.ToString() == "Closed") conn.Open();
            SqlCommand comm = new SqlCommand(SqlStr, conn);
            comm.ExecuteNonQuery();
            comm.Dispose();
            if (conn.State.ToString() == "Open") conn.Close();            GridView1.EditIndex = -1;
            GridViewBind();
        }
        catch (Exception ex)
        {
            Response.Write("数据库错误，错误原因：" + ex.Message);
            Response.End();
        }
    }
}sql server2000生成表代码：
Create TABLE [dbo].[test01] (
    [id] [decimal](18, 0) IDENTITY (1, 1) NOT NULL ,
    [name] [varchar] (50) COLLATE Chinese_PRC_CI_AS NULL ,
    [card] [varchar] (50) COLLATE Chinese_PRC_CI_AS NULL ,
    [xueli] [varchar] (50) COLLATE Chinese_PRC_CI_AS NULL ,
    [price] [decimal](18, 0) NULL ,
    [createdate] [datetime] NULL 
) ON [PRIMARY]
GOAlter TABLE [dbo].[test01] ADD 
    CONSTRAINT [DF_test01_createdate] DEFAULT (getdate()) FOR [createdate],
    CONSTRAINT [PK_test01] PRIMARY KEY CLUSTERED 
    (
        [id]
    ) ON [PRIMARY] 
GO
Create TABLE [dbo].[xueli](
    [id] [int] IDENTITY(1,1) NOT NULL,
    [code] [int] NULL,
    [description] [nvarchar](50) COLLATE Chinese_PRC_CI_AS NULL,
CONSTRAINT [PK_xueli] PRIMARY KEY CLUSTERED 
(
    [id] ASC
)WITH (IGNORE_DUP_KEY = OFF) ON [PRIMARY]
) ON [PRIMARY]