为什么无法使用 GridView 中的 DropDownList 更新此列？答案

【问题标题】：Why this column cannot be updated using DropDownList inside the GridView?为什么无法使用 GridView 中的 DropDownList 更新此列？
【发布时间】：2012-07-10 22:05:03
【问题描述】：

我有以下数据库设计：

Employee Table: Username, Name, JobTitle, BadgeNo, IsActive, DivisionCode
Divisions Table: SapCode, DivisionShortcut

（DivisionCode 是 Divisions 表中 SapCode 的外键）

我有一个 GridView，我用它来添加、删除和更新/编辑员工信息。此信息是员工用户名、姓名、徽章编号、职位名称、IsActive 和部门快捷方式。部门将列在 DropDownList 中。现在的问题是：更新员工的部门。我编写了代码，但出现以下错误： *

列名“DivisionShortcut”无效。

ASP.NET 代码：

    <asp:TemplateField HeaderText="Division">
        <ItemTemplate>
            <%# Eval("DivisionShortcut")%>
        </ItemTemplate>
        <EditItemTemplate>
            <asp:DropDownList ID="DivisionsList" runat="server" DataSourceID="DivisionsListDataSource"
                                DataTextField="DivisionShortcut" DataValueField="SapCode">
            </asp:DropDownList>
        </EditItemTemplate>
    </asp:TemplateField>

    <asp:BoundField DataField="Username" HeaderText="Network ID" ReadOnly="True" 
        SortExpression="Username" />

    <asp:TemplateField HeaderText="Name">
        <ItemTemplate>
            <%# Eval("Name")%>
        </ItemTemplate>
        <EditItemTemplate>
            <asp:TextBox ID="txtEmployeeName" runat="server" Text='<%# Bind("Name")%>' />
        </EditItemTemplate>
    </asp:TemplateField>

    <asp:TemplateField HeaderText="Job Title">
        <ItemTemplate>
            <%# Eval("JobTitle")%>
        </ItemTemplate>
        <EditItemTemplate>
            <asp:TextBox ID="txtJobTitle" runat="server" Text='<%# Bind("JobTitle")%>' />
        </EditItemTemplate>
    </asp:TemplateField>

    <asp:TemplateField HeaderText="Badge No.">
        <ItemTemplate>
            <%# Eval("BadgeNo")%>
        </ItemTemplate>
        <EditItemTemplate>
            <asp:TextBox ID="txtBadgeNo" runat="server" Text='<%# Bind("BadgeNo")%>' />
        </EditItemTemplate>
    </asp:TemplateField>

    <asp:TemplateField HeaderText="Is Active?">
        <ItemTemplate>
            <%# Eval("IsActive")%>
        </ItemTemplate>
        <EditItemTemplate>
            <asp:CheckBox ID="isActive" runat="server" 
                          Checked='<%# Eval("IsActive").ToString().Equals("True") %>'/>
        </EditItemTemplate>
    </asp:TemplateField>

    <asp:TemplateField HeaderText="Delete?">
        <ItemTemplate>
            <span onclick="return confirm('Are you sure to Delete the record?')">
                <asp:ImageButton ID="lnkB" runat="server" ImageUrl="Images/icons/delete24.png" CommandName="Delete" />
            </span>
        </ItemTemplate>
    </asp:TemplateField>
</Columns>

SelectCommand="SELECT     dbo.Divisions.DivisionShortcut, dbo.employee.Username, dbo.employee.Name, dbo.employee.JobTitle, dbo.employee.BadgeNo, dbo.employee.IsActive
                FROM         dbo.Divisions INNER JOIN
                            dbo.employee ON dbo.Divisions.SapCode = dbo.employee.DivisionCode"
UpdateCommand="UPDATE [employee] SET [Name] = @Name, [JobTitle] = @JobTitle, 
                                    [BadgeNo] = @BadgeNo WHERE [Username] = @Username"
DeleteCommand="DELETE FROM [employee] WHERE [Username] = @Username">
<UpdateParameters>
    <asp:Parameter Name="Name" Type="String"  />
    <asp:Parameter Name="JobTitle" Type="String" />
    <asp:Parameter Name="BadgeNo" Type="String" />
    <asp:Parameter Name="Username" Type="String" />
</UpdateParameters>
<DeleteParameters>
    <asp:Parameter Name="Username" Type="String" />
</DeleteParameters>

" SelectCommand="SELECT * FROM Divisions">

代码隐藏： //用于编辑GridView中的任何行 protected void GridView1_RowEditing（对象发送者，GridViewEditEventArgs e） { GridView1.EditIndex = e.NewEditIndex; }

//For canceling any editng in any row in the GridView
protected void GridView1_RowCancelingEdit(object sender, GridViewCancelEditEventArgs e)
{
    e.Cancel = true;
    GridView1.EditIndex = -1;
}

//For updating the information in any row in the GridView
protected void GridView1_RowUpdating(object sender, GridViewUpdateEventArgs e)
{
    GridViewRow gvrow = GridView1.Rows[e.RowIndex];

    DropDownList DivisionsList = (DropDownList)gvrow.FindControl("DivisionsList"); 

    TextBox txtEmployeeName = (TextBox)gvrow.FindControl("txtEmployeeName");
    TextBox txtJobTitle = (TextBox)gvrow.FindControl("txtJobTitle");
    TextBox txtBadgeNo = (TextBox)gvrow.FindControl("txtBadgeNo");

    CheckBox isActive = (CheckBox)gvrow.FindControl("isActive");

    //For getting the ID (primary key) of that row
    string username = GridView1.DataKeys[e.RowIndex].Value.ToString();

    string name = txtEmployeeName.Text;
    string jobTitle = txtJobTitle.Text;
    string badgeNo = txtBadgeNo.Text;
    string division = DivisionsList.SelectedValue.ToString();

    UpdateEmployeeInfo(username, name, jobTitle, badgeNo, division);
}


private void UpdateEmployeeInfo(string username, string name, string jobTitle, string badgeNo, string division)
{
    string connString = ConfigurationManager.ConnectionStrings["UsersInfoDBConnectionString"].ConnectionString;
    SqlConnection conn = new SqlConnection(connString);
    string update = @"UPDATE Employee SET Name = @Name, JobTitle = @JobTitle, 
                        BadgeNo = @BadgeNo, DivisionShortcut = @division WHERE Username = @Username; 
                        UPDATE Divisions SET [DivisionShortcut] = @division WHERE SapCode = @SapCode;";

    SqlCommand cmd = new SqlCommand(update, conn);

    cmd.Parameters.AddWithValue("@Name", name);
    cmd.Parameters.AddWithValue("@JobTitle", jobTitle);
    cmd.Parameters.AddWithValue("@BadgeNo", badgeNo);
    cmd.Parameters.AddWithValue("@division", division);
    cmd.Parameters.AddWithValue("@Username", username);
    //cmd.Parameters.AddWithValue("@IsActive", isActive.checked);

    try
    {
        conn.Open();
        cmd.ExecuteNonQuery();
        conn.Close();

        GridView1.EditIndex = -1;
    }
    catch (Exception ex)
    {
        throw ex;
    }
    finally
    {
        cmd.Dispose();
        conn.Close();
        conn.Dispose();
    }
    GridView1.DataBind();
}

那么我怎样才能使用 GridView 中的 DropDownList 更新员工的 Divivsion 字段？

更新：

这是我更新的代码，但仍然没有任何效果： ASP.NET 代码：

<asp:GridView ID="GridView1" runat="server" AllowSorting="True" 
            AutoGenerateColumns="False" DataKeyNames="Username" 
            DataSourceID="SqlDataSource1" BorderWidth="1px" BackColor="#DEBA84" 
             CellPadding="3" CellSpacing="2" BorderStyle="None" 
             BorderColor="#DEBA84">
            <FooterStyle ForeColor="#8C4510" 
              BackColor="#F7DFB5"></FooterStyle>
            <PagerStyle ForeColor="#8C4510" 
              HorizontalAlign="Center"></PagerStyle>
            <HeaderStyle ForeColor="White" Font-Bold="True" 
              BackColor="#A55129"></HeaderStyle>
            <Columns>
                <asp:CommandField ButtonType="Image" ShowEditButton="true" ShowCancelButton="true"
                                EditImageUrl="Images/icons/edit24.png" UpdateImageUrl="Images/icons/update24.png" 
                                CancelImageUrl="Images/icons/cancel324.png" />

                <asp:TemplateField HeaderText="Division">
                    <ItemTemplate>
                        <%# Eval("DivisionShortcut")%>
                        <asp:HiddenField ID="divisioncode" value='<%#Eval("divisioncode")%>' runat="server" />
                    </ItemTemplate>
                    <EditItemTemplate>
                        <asp:DropDownList ID="DivisionsList" runat="server" DataSourceID="DivisionsListDataSource"
                                          DataTextField="DivisionShortcut" DataValueField="SapCode">
                        </asp:DropDownList>
                    </EditItemTemplate>
                </asp:TemplateField>

                <asp:BoundField DataField="Username" HeaderText="Network ID" ReadOnly="True" 
                    SortExpression="Username" />

                <asp:TemplateField HeaderText="Name">
                    <ItemTemplate>
                        <%# Eval("Name")%>
                    </ItemTemplate>
                    <EditItemTemplate>
                        <asp:TextBox ID="txtEmployeeName" runat="server" Text='<%# Bind("Name")%>' />
                    </EditItemTemplate>
                </asp:TemplateField>

                <asp:TemplateField HeaderText="Job Title">
                    <ItemTemplate>
                        <%# Eval("JobTitle")%>
                    </ItemTemplate>
                    <EditItemTemplate>
                        <asp:TextBox ID="txtJobTitle" runat="server" Text='<%# Bind("JobTitle")%>' />
                    </EditItemTemplate>
                </asp:TemplateField>

                <asp:TemplateField HeaderText="Badge No.">
                    <ItemTemplate>
                        <%# Eval("BadgeNo")%>
                    </ItemTemplate>
                    <EditItemTemplate>
                        <asp:TextBox ID="txtBadgeNo" runat="server" Text='<%# Bind("BadgeNo")%>' />
                    </EditItemTemplate>
                </asp:TemplateField>

                <asp:TemplateField HeaderText="Is Active?">
                    <ItemTemplate>
                        <%# Eval("IsActive")%>
                    </ItemTemplate>
                    <EditItemTemplate>
                        <asp:CheckBox ID="isActive" runat="server" 
                                      Checked='<%# Eval("IsActive").ToString().Equals("True") %>'/>
                    </EditItemTemplate>
                </asp:TemplateField>

                <asp:TemplateField HeaderText="Delete?">
                    <ItemTemplate>
                        <span onclick="return confirm('Are you sure to Delete the record?')">
                            <asp:ImageButton ID="lnkB" runat="server" ImageUrl="Images/icons/delete24.png" CommandName="Delete" />
                        </span>
                    </ItemTemplate>
                </asp:TemplateField>
            </Columns>
        </asp:GridView>
        <asp:SqlDataSource ID="SqlDataSource1" runat="server" 
            ConnectionString="<%$ ConnectionStrings:UsersInfoDBConnectionString %>" 

            SelectCommand="SELECT     dbo.Divisions.DivisionShortcut,dbo.employee.DivisionCode, dbo.employee.Username, dbo.employee.Name, dbo.employee.JobTitle, dbo.employee.BadgeNo, dbo.employee.IsActive
                    FROM         dbo.Divisions INNER JOIN
                                dbo.employee ON dbo.Divisions.SapCode = dbo.employee.DivisionCode"
            UpdateCommand="UPDATE [employee] SET [Name] = @Name, [JobTitle] = @JobTitle, 
                                                [BadgeNo] = @BadgeNo WHERE [Username] = @Username"
            DeleteCommand="DELETE FROM [employee] WHERE [Username] = @Username">
            <UpdateParameters>
                <asp:Parameter Name="Name" Type="String"  />
                <asp:Parameter Name="JobTitle" Type="String" />
                <asp:Parameter Name="BadgeNo" Type="String" />
                <asp:Parameter Name="Username" Type="String" />
            </UpdateParameters>
            <DeleteParameters>
                <asp:Parameter Name="Username" Type="String" />
            </DeleteParameters>
        </asp:SqlDataSource>

        <asp:SqlDataSource ID="DivisionsListDataSource" runat="server" 
            ConnectionString="<%$ ConnectionStrings:UsersInfoDBConnectionString %>" 
            SelectCommand="SELECT * FROM Divisions">
        </asp:SqlDataSource>

代码隐藏：

//For editing any row in the GridView
    protected void GridView1_RowEditing(object sender, GridViewEditEventArgs e) 
    {
        GridView1.EditIndex = e.NewEditIndex;
    }

    //For canceling any editng in any row in the GridView
    protected void GridView1_RowCancelingEdit(object sender, GridViewCancelEditEventArgs e)
    {
        e.Cancel = true;
        GridView1.EditIndex = -1;
    }

    //For updating the information in any row in the GridView
    protected void GridView1_RowUpdating(object sender, GridViewUpdateEventArgs e)
    {
        GridViewRow gvrow = GridView1.Rows[e.RowIndex];

        DropDownList DivisionsList = (DropDownList)gvrow.FindControl("DivisionsList");
        HiddenField hidden = (HiddenField)gvrow.FindControl("divisioncode");
        string division_code = hidden.Value.ToString();

        TextBox txtEmployeeName = (TextBox)gvrow.FindControl("txtEmployeeName");
        TextBox txtJobTitle = (TextBox)gvrow.FindControl("txtJobTitle");
        TextBox txtBadgeNo = (TextBox)gvrow.FindControl("txtBadgeNo");

        CheckBox isActive = (CheckBox)gvrow.FindControl("isActive");

        //For getting the ID (primary key) of that row
        string username = GridView1.DataKeys[e.RowIndex].Value.ToString();

        string name = txtEmployeeName.Text;
        string jobTitle = txtJobTitle.Text;
        string badgeNo = txtBadgeNo.Text;
        string division = DivisionsList.SelectedValue.ToString();

        //string divisioncode = DivisionsList.SelectedValue;

        UpdateEmployeeInfo(username, name, jobTitle, badgeNo, division, division_code);
    }


    private void UpdateEmployeeInfo(string username, string name, string jobTitle, string badgeNo, string division, string divisioncode)
    {
        string connString = ConfigurationManager.ConnectionStrings["UsersInfoDBConnectionString"].ConnectionString;
        SqlConnection conn = new SqlConnection(connString);
        string update = @"UPDATE Employee SET Name = @Name, JobTitle = @JobTitle, 
                            BadgeNo = @BadgeNo WHERE Username = @Username; 
                            UPDATE Divisions SET [DivisionShortcut] = @division WHERE SapCode = @SapCode;";

        SqlCommand cmd = new SqlCommand(update, conn);

        cmd.Parameters.AddWithValue("@Name", name);
        cmd.Parameters.AddWithValue("@JobTitle", jobTitle);
        cmd.Parameters.AddWithValue("@BadgeNo", badgeNo);
        cmd.Parameters.AddWithValue("@division", division);
        cmd.Parameters.AddWithValue("@Username", username);
        cmd.Parameters.AddWithValue("@SapCode", divisioncode);
        //cmd.Parameters.AddWithValue("@IsActive", isActive.checked);

        try
        {
            conn.Open();
            cmd.ExecuteNonQuery();
            conn.Close();

            GridView1.EditIndex = -1;
        }
        catch (Exception ex)
        {
            throw ex;
        }
        finally
        {
            cmd.Dispose();
            conn.Close();
            conn.Dispose();
        }
        GridView1.DataBind();
    }

【问题讨论】：

标签： c# asp.net sql gridview sql-server-2008-r2

【解决方案1】：

您在以下行代码部分有错误：

string update = @"UPDATE Employee SET Name = @Name, JobTitle = @JobTitle, 
                        BadgeNo = @BadgeNo, DivisionShortcut = @division WHERE Username = @Username;
                                                     ^^
                        UPDATE Divisions SET [DivisionShortcut] = @division WHERE SapCode = @SapCode;";

dividionshortcut 不是员工表的成员。只需将其从标记位置删除并再次运行它，我相信这将消除您的错误。

要使用的代码。在您的网格视图中添加以下字段：

 <asp:TemplateField HeaderText="Division">
            <ItemTemplate>
                <%# Eval("DivisionShortcut")%>
<asp:HiddenField ID="divisioncode" value='<%#Eval("divisioncode")%>' runat="server" />
            </ItemTemplate>
            <EditItemTemplate>
                <asp:DropDownList ID="DivisionsList" runat="server" DataSourceID="DivisionsListDataSource"
                                    DataTextField="DivisionShortcut" DataValueField="SapCode">
                </asp:DropDownList>
            </EditItemTemplate>
        </asp:TemplateField>

首先使用下面的选择命令

 SelectCommand="SELECT     dbo.Divisions.DivisionShortcut,dbo.employee.DivisionCode, dbo.employee.Username, dbo.employee.Name, dbo.employee.JobTitle, dbo.employee.BadgeNo, dbo.employee.IsActive
                    FROM         dbo.Divisions INNER JOIN
                                dbo.employee ON dbo.Divisions.SapCode = dbo.employee.DivisionCode"
    UpdateCommand="UPDATE [employee] SET [Name] = @Name, [JobTitle] = @JobTitle, 
                                        [BadgeNo] = @BadgeNo WHERE [Username] = @Username"
    DeleteCommand="DELETE FROM [employee] WHERE [Username] = @Username">
    <UpdateParameters>
        <asp:Parameter Name="Name" Type="String"  />
        <asp:Parameter Name="JobTitle" Type="String" />
        <asp:Parameter Name="BadgeNo" Type="String" />
        <asp:Parameter Name="Username" Type="String" />
    </UpdateParameters>
    <DeleteParameters>
        <asp:Parameter Name="Username" Type="String" />
    </DeleteParameters>

第二次调用行更新事件时使用如下：

protected void GridView1_RowUpdating(object sender, GridViewUpdateEventArgs e)
{
    GridViewRow gvrow = GridView1.Rows[e.RowIndex];

    DropDownList DivisionsList = (DropDownList)gvrow.FindControl("DivisionsList"); 
    HiddenField hidden = (HiddenField)gvrow.FindControl("divisioncode");
    string division_code=hidden.value.ToString();
    TextBox txtEmployeeName = (TextBox)gvrow.FindControl("txtEmployeeName");
    TextBox txtJobTitle = (TextBox)gvrow.FindControl("txtJobTitle");
    TextBox txtBadgeNo = (TextBox)gvrow.FindControl("txtBadgeNo");

    CheckBox isActive = (CheckBox)gvrow.FindControl("isActive");

    //For getting the ID (primary key) of that row
    string username = GridView1.DataKeys[e.RowIndex].Value.ToString();

    string name = txtEmployeeName.Text;
    string jobTitle = txtJobTitle.Text;
    string badgeNo = txtBadgeNo.Text;
    string division = DivisionsList.SelectedValue.ToString();

    UpdateEmployeeInfo(username, name, jobTitle, badgeNo, division,division_code);
}

现在在后面的代码中为您的函数中的除法代码添加一个参数并调用以下更新函数：

 private void UpdateEmployeeInfo(string username, string name, string jobTitle, string badgeNo, string division,string divisioncode)
    {
        string connString = ConfigurationManager.ConnectionStrings["UsersInfoDBConnectionString"].ConnectionString;
        SqlConnection conn = new SqlConnection(connString);
        string update = @"UPDATE Employee SET Name = @Name, JobTitle = @JobTitle, 
                            BadgeNo = @BadgeNo WHERE Username = @Username; 
                            UPDATE Divisions SET [DivisionShortcut] = @division WHERE SapCode = @SapCode;";

        SqlCommand cmd = new SqlCommand(update, conn);

        cmd.Parameters.AddWithValue("@Name", name);
        cmd.Parameters.AddWithValue("@JobTitle", jobTitle);
        cmd.Parameters.AddWithValue("@BadgeNo", badgeNo);
        cmd.Parameters.AddWithValue("@division", division);
        cmd.Parameters.AddWithValue("@Username", username);
        cmd.Parameters.AddWithValue("@DapCode", divisioncode);

        try
        {
            conn.Open();
            cmd.ExecuteNonQuery();
            conn.Close();

            GridView1.EditIndex = -1;
        }
        catch (Exception ex)
        {
            throw ex;
        }
        finally
        {
            cmd.Dispose();
            conn.Close();
            conn.Dispose();
        }
        GridView1.DataBind();
    }

希望能解决你的问题

【讨论】：

我收到以下错误：'必须声明标量变量“@SapCode”。'
如何获取 SapCode 的值以及我应该在哪里使用它。很抱歉问了很多，但我是一个新的 ASP.NET 开发人员。请看看我上面的代码隐藏。
您的 DivisionCode 是 Divisions 表中 SapCode 的外键，因此您可以使用员工表中更新员工的部门代码作为 sapcode 的值，因为它们都是相同的（我希望） .
您在此函数中添加的除法代码变量的值是多少。众所周知，除法=dropdownlist.text的值，那么除法码呢
您可以使用 GV 中的隐藏字段并将其分配给从选择查询中收到的部门代码的值。在您后面的代码中，您可以访问该值以及其他值并将其发送到您的更新函数。

【解决方案2】：

这是你的代码

UPDATE Employee SET Name = @Name, JobTitle = @JobTitle, 
                    BadgeNo = @BadgeNo, DivisionShortcut = @division WHERE Username =     @Username;

DivisionShortcut 不是 Employee 表的成员。你下面有一个更新声明，所以我认为你只是不小心把它留在了那里，从这个更新行中删除它可以解决这个问题。

【讨论】：

我删除了它，但仍然遇到一个错误：'必须声明标量变量“@SapCode”。'