在GridView1中的DropDownList如何赋值（邦定）？

Question

我在GridView1中有TextBox也有DropDownList，TextBox赋值没有问题，但是DropDownList赋值却出现问题？是我的写法错了吗？<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" CssClass="GVTab"
            onrowdatabound="GridView1_RowDataBound" onrowdeleting="GridView1_RowDeleting" DataKeyNames="id" >
            <Columns>
                <asp:BoundField DataField="id" HeaderText="ID" Visible="false" />
                <asp:CommandField ShowDeleteButton="True" />
                <asp:TemplateField HeaderText="物料编号">
                    <ItemTemplate>
                        <asp:TextBox ID="pno" runat="server" Enabled="false" 
                            Text='<%# Eval("pno") %>' Width="100px" />
                        </asp:textbox>
                    </ItemTemplate>
                </asp:TemplateField>
<asp:TemplateField HeaderText="仓位">
                    <ItemTemplate>
                        <asp:DropDownList ID="loc" runat="server" Enabled="true" 
                            SelectValue='<%# Eval("loc") %>' Width="80px" />     //<-----请问这个地方如何写
                        </asp:dropdownList>
                    </ItemTemplate>
                </asp:TemplateField>
                <asp:TemplateField HeaderText="备注">
                    <ItemTemplate>
                        <asp:TextBox ID="re" runat="server" Enabled="true" 
                            Text='<%# Eval("re") %>' Width="180px" />
                        </asp:textbox>
                    </ItemTemplate>
                </asp:TemplateField>
           </Columns>
        </asp:GridView>

Answer 1

SelectedValue='<%# Eval("loc") %>' Width="80px" /> //<-----请问这个地方如何写
  

Answer 2

另外，在定义DropdownList的时候可以定义数据源，例如（仅仅是举例）<asp:DropDownList ID="loc" runat="server" DataSource='<%# Get仓位集合((string)Eval("pno")) %>' ......protected List<string> Get仓位集合(string 物料)
{
    return 查询数据库返回能够保存某个或者某种物料的所有仓位(物料);
}当然，如果仓位集合是多个属性的，例如返回的是"List<仓位>"类型或者DataTable类型的，你还可以在声明中指出显示所用的属性名、值所用的属性名。当实际使用时，其实应该在“查询数据库返回......”之前增加一句，先从数据缓存里取数据。当然也可以仅仅缓存在本页对象的private变量里（要根据所使用的查询条件——仓位——而分开保存），这样本页上这个GridView种不同行的DropdownList的数据绑定就不一定需要重复去读取数据库了。最后，这个方法其实就是BLL方法。这里演示的是用很干净的方法将界面声明和BLL方法分开，代码维护起来肯定比那种跑到什么GridView的DataBound事件处理方法中又访问BLL有查找和设置控件要清晰方便了。

Answer 3

查找控件foreach(GridViewRow row in GridView1.Rows){
dropdown drop=row.findControl("") as DropDownlist;
drop.datasource="";
drop.dadtabind();
}

Answer 4

<ItemTemplate>
<asp:DropDownList ID="ddlSort" runat="server" Width="98%">
    </asp:DropDownList>
<asp:HiddenField ID="Hd_Sort" runat="server" Value=' <%# Eval("BalSort")%>' />
</ItemTemplate>
protected void gv_RowDataBound(object sender, GridViewRowEventArgs e)
        {
            if (e.Row.RowIndex != -1)
            {  if (e.Row.RowState == DataControlRowState.Edit || e.Row.RowState == (DataControlRowState.Alternate | DataControlRowState.Edit))
            {
                ((DropDownList)e.Row.FindControl("ddlSort")).SelectedValue = ((HiddenField)e.Row.FindControl("Hd_Sort")).Value;
            }
            }
        }protected void gv_RowEditing(object sender, GridViewEditEventArgs e)
        {
            gv.EditIndex = e.NewEditIndex;
            string strSort = ((DropDownList)gv.Rows[e.NewEditIndex].FindControl("ddlSort")).SelectedValue.Trim();
            gv.EditIndex = -1;
            BindData();
        }

Answer 5

SelectValue='<%# Eval("loc") %>' Width="80px" /> 
我不太推荐赋值，说不上为什么，
建议给selectIndex赋值
我一般都这样用
 void dllBind()
    {
        string sSql;
        sqlcon = new SqlConnection(sConnStr);
        sqlcon.Open();
        SqlDataReader dr;
        SqlCommand sc;
        // 学生类别
        sSql = "SELECT [XSLB_DM], [XSLB_MC] FROM [XSLB]";
        sc= new SqlCommand(sSql, sqlcon);
        dr = sc.ExecuteReader();
        if (dr != null)
        {
            while (dr.Read())
            {
                string txt = dr["XSLB_MC"].ToString().Trim();
                string val = dr["XSLB_DM"].ToString().Trim();
                ddlXSLB.Items.Add(new ListItem(txt, val));
            }
        }
        sqlcon.Close();
        //政治面貌
        sSql = "SELECT [ZZMM_DM], [ZZMM_MC] FROM [ZZMM]";
        sqlcon.Open();
        sc = new SqlCommand(sSql, sqlcon);
        dr = sc.ExecuteReader();
        if (dr != null)
        {
            while (dr.Read())
            {
                string txt = dr["ZZMM_MC"].ToString().Trim();
                string val = dr["ZZMM_DM"].ToString().Trim();
                ddlZZMM.Items.Add(new ListItem(txt, val));
            }
        }
        sqlcon.Close();
        //学生系所
        sSql = "SELECT [XSXS_DM], [XSXS_MC] FROM [XSXS]";
        sqlcon.Open();
        sc = new SqlCommand(sSql, sqlcon);
        dr = sc.ExecuteReader();
        if (dr != null)
        {
            while (dr.Read())
            {
                string txt = dr["XSXS_MC"].ToString().Trim();
                string val = dr["XSXS_DM"].ToString().Trim();
                ddlXSXS.Items.Add(new ListItem(txt, val));
            }
        }
        sqlcon.Close();
        //专业
        sSql = "SELECT [XSZY_DM], [XSZY_MC] FROM [XSZY]";
        sqlcon.Open();
        sc = new SqlCommand(sSql, sqlcon);
        dr = sc.ExecuteReader();
        if (dr != null)
        {
            while (dr.Read())
            {
                string txt = dr["XSZY_MC"].ToString().Trim();
                string val = dr["XSZY_DM"].ToString().Trim();
                ddlXSZY.Items.Add(new ListItem(txt, val));
            }
        }
        sqlcon.Close();
        //年级
        sSql = "SELECT [XSJB_DM], [XSJB_MC] FROM [XSJB]";
        sqlcon.Open();
        sc = new SqlCommand(sSql, sqlcon);
        dr = sc.ExecuteReader();
        if (dr != null)
        {
            while (dr.Read())
            {
                string txt = dr["XSJB_MC"].ToString().Trim();
                string val = dr["XSJB_DM"].ToString().Trim();
                ddlXSNJ.Items.Add(new ListItem(txt, val));
            }
        }
        sqlcon.Close();
    }

Answer 6

不好意思贴成添加的了    void Bind(string XSXH)
    {
        
        string sSql = "SELECT [XSXX_XH], [XSXX_MM], [XSXX_XM], [XSXX_SFZH], [XSXX_XB], [XSXX_XSLB], [XSXX_JG], "+
            "[XSXX_CSRQ], [XSXX_ZZMM], [XSXX_XS], [XSXX_RXRQ], [XSXX_ZY], [XSXX_NJ], [XSXX_BJ], [XSXX_SM] FROM [XSXX]  " +
            "WHERE ([XSXX_XH] = '"+XSXH+"') " ;
        string sTmp;
        sqlcon = new SqlConnection(sConnStr);
        sqlcon.Open();
        SqlDataReader dr;
        SqlCommand sc = new SqlCommand(sSql, sqlcon);
        dr = sc.ExecuteReader();
        if (dr != null)
        {
            if (dr.Read())
            {
                lblXH.Text = XSXH;
                tbxMM.Text = dr["XSXX_MM"].ToString().Trim();
                tbxXM.Text = dr["XSXX_XM"].ToString().Trim();
                tbxSFZH.Text = dr["XSXX_SFZH"].ToString().Trim();
                //sTmp = "";
                sTmp = dr["XSXX_XB"].ToString().Trim();
                ddlXB.SelectedIndex = ddlXB.Items.IndexOf(ddlXB.Items.FindByValue(sTmp));
                //sTmp = "";
                sTmp = dr["XSXX_XSLB"].ToString().Trim();
                ddlXSLB.SelectedIndex = ddlXSLB.Items.IndexOf(ddlXSLB.Items.FindByValue(sTmp));
                tbxJG.Text = dr["XSXX_JG"].ToString().Trim();
                tbxCSRQ.Text =Convert.ToDateTime(dr["XSXX_CSRQ"].ToString().Trim()).ToShortDateString();
                //sTmp = "";
                sTmp = dr["XSXX_ZZMM"].ToString().Trim();
                ddlZZMM.SelectedIndex = ddlZZMM.Items.IndexOf(ddlZZMM.Items.FindByValue(sTmp));
                //sTmp = "";
                sTmp = dr["XSXX_XS"].ToString().Trim();
                ddlXSXS.SelectedIndex = ddlXSXS.Items.IndexOf(ddlXSXS.Items.FindByValue(sTmp));
                tbxRXRQ.Text = Convert.ToDateTime(dr["XSXX_RXRQ"].ToString().Trim()).ToShortDateString();
                //sTmp = "";
                sTmp = dr["XSXX_ZY"].ToString().Trim();
                ddlXSZY.SelectedIndex = ddlXSZY.Items.IndexOf(ddlXSZY.Items.FindByValue(sTmp));
                //sTmp = "";
                sTmp = dr["XSXX_NJ"].ToString().Trim();
                ddlXSNJ.SelectedIndex = ddlXSNJ.Items.IndexOf(ddlXSNJ.Items.FindByValue(sTmp));
                tbxBJ.Text = dr["XSXX_BJ"].ToString().Trim();
                if (dr["XSXX_SM"] != DBNull.Value)
                {
                    tbxSM.Text = dr["XSXX_SM"].ToString().Trim();
                }
                else
                {
                    tbxSM.Text = "无";
                }
            }
        }
        sqlcon.Close();    }