C# 如何在回发后将文本保存到绑定数据库数据的texbox中

下面是组成gridview的模板字段之一。标签和文本框的所有值都来自数据库，我想重点关注这个特定的文本框，以下是aspx代码：

<asp:TemplateField HeaderText="ServiceStart" SortExpression="ServiceStart">
        <EditItemTemplate>
            <asp:TextBox ID="txtEditServiceStart" runat="server" type="date" Text='<%# Bind("ServiceStart","{0:d}") %>'  Width="128px"></asp:TextBox>
        </EditItemTemplate>
        <ItemTemplate>
            <asp:Label ID="LblItemServiceStart" runat="server" Text='<%# Bind("ServiceStart","{0:d}") %>' ></asp:Label>
        </ItemTemplate>
</asp:TemplateField>

以下是如何编辑、取消编辑、更新的代码：

protected void GridView1_RowCommand(object sender, GridViewCommandEventArgs e)
{
    if (e.CommandName == "EditRow")
    {
        int rowIndex = ((GridViewRow)((LinkButton)e.CommandSource).NamingContainer).RowIndex;
        GridView1.EditIndex = rowIndex;

        BindGrid();
    }
    else if (e.CommandName == "CancelUpdate")
    {
        GridView1.EditIndex = -1;
        BindGrid();
    }
    else if (e.CommandName == "UpdateRow")
    {
        int rowIndex = ((GridViewRow)((LinkButton)e.CommandSource).NamingContainer).RowIndex;

        string ContractNo = ((TextBox)GridView1.Rows[rowIndex].FindControl("txtEditContractNo")).Text;
        string contractDate = ((TextBox)GridView1.Rows[rowIndex].FindControl("txtEditContractDate")).Text;  
        string contractDuration = ((TextBox)GridView1.Rows[rowIndex].FindControl("txtEditContractDuration")).Text;
        string serviceStart = ((TextBox)GridView1.Rows[rowIndex].FindControl("txtEditServiceStart")).Text;
        string contractDetails = ((TextBox)GridView1.Rows[rowIndex].FindControl("txtEditContractDetails")).Text;
        string contractValue = ((TextBox)GridView1.Rows[rowIndex].FindControl("txtEditContractValue")).Text;
        string DropDownServed = ((DropDownList)GridView1.Rows[rowIndex].FindControl("DropDownServed")).Text;

        AccessLayer.UpdateContract(ContractNo, contractDate, contractDuration, serviceStart, contractDetails, contractValue, DropDownServed);
        GridView1.EditIndex = -1;
        BindGrid();

    }
}

AccessLayer=更新合同：

public static int UpdateContract(string ContractNo, string ContractDate, string ContractDuration, string ServiceStart, string ContractDetails, string ContractValue, string Served)
{
    string css = ConfigurationManager.ConnectionStrings["dbx"].ConnectionString;
    using (SqlConnection con = new SqlConnection(css))
    {
        string UpdateQuery = "UPDATE SCHOLARSHIPCONTRACT SET ContractDate= @ContractDate, ContractDuration = @ContractDuration, ServiceStart = @ServiceStart, ContractDetails = @ContractDetails, ContractValue= @ContractValue, Served = @Served WHERE ContractNo =@ContractNo";
        SqlCommand UpdateCmd = new SqlCommand(UpdateQuery, con);

        SqlParameter paramOriginalContractNo = new SqlParameter("ContractNo", ContractNo);
        UpdateCmd.Parameters.Add(paramOriginalContractNo);
        SqlParameter paramContractDate = new SqlParameter("@ContractDate", ContractDate);
        UpdateCmd.Parameters.Add(paramContractDate);
        SqlParameter paramContractDuration = new SqlParameter("@ContractDuration", ContractDuration);
        UpdateCmd.Parameters.Add(paramContractDuration);
        SqlParameter paramServiceStart = new SqlParameter("@ServiceStart", ServiceStart);
        UpdateCmd.Parameters.Add(paramServiceStart);
        SqlParameter paramContractDetails = new SqlParameter("@ContractDetails", ContractDetails);
        UpdateCmd.Parameters.Add(paramContractDetails);
        SqlParameter paramContractValue = new SqlParameter("@ContractValue", ContractValue);
        UpdateCmd.Parameters.Add(paramContractValue);
        SqlParameter paramServed = new SqlParameter("@Served", Served);
        UpdateCmd.Parameters.Add(paramServed);
        con.Open();
        return UpdateCmd.ExecuteNonQuery();
    }
}

---

请建议我可以在aspx或c代码中添加的方式/方法谢谢你

你的问题是你总是更新你的合同日期。您必须编辑查询字符串。Add COALESCE将为ContractDate分配一个值，如果已填充该值，则该值为：@ContractDate，否则它将分配ContractDate的现有值。将方法中ContractDate的类型更改为？DateTime，它允许您将其放入方法null中。当你们调用这个方法时，若日期被编辑，只需勾选文本框，若并没有设置为空，就把它放在方法中

 public static int UpdateContract(string ContractNo, DateTime? ContractDate, string ContractDuration, string ServiceStart, string ContractDetails, string ContractValue, string Served)
    {
        string css = ConfigurationManager.ConnectionStrings["dbx"].ConnectionString;
        using (SqlConnection con = new SqlConnection(css))
        {
            string UpdateQuery = "UPDATE SCHOLARSHIPCONTRACT SET ContractDate=COALESCE(@ContractDate=ContractDate), ContractDuration = @ContractDuration, ServiceStart = @ServiceStart, ContractDetails = @ContractDetails, ContractValue= @ContractValue, Served = @Served WHERE ContractNo =@ContractNo";
            SqlCommand UpdateCmd = new SqlCommand(UpdateQuery, con);


            UpdateCmd.Parameters.AddWithValue("ContractNo", ContractNo);
            //Here you have to convert string to DateTime
            UpdateCmd.Parameters.AddWithValue("@ContractDate", ContractDate);
            UpdateCmd.Parameters.AddWithValue("@ContractDuration", ContractDuration);
            UpdateCmd.Parameters.AddWithValue("@ServiceStart", ServiceStart);
            UpdateCmd.Parameters.AddWithValue("@ContractDetails", ContractDetails);
            UpdateCmd.Parameters.AddWithValue("@ContractValue", ContractValue);
            UpdateCmd.Parameters.AddWithValue("@Served", Served);

            con.Open();
            return UpdateCmd.ExecuteNonQuery();
        }
    }

---

更新后的日期也是1900年1月1日，单位为db？我怀疑您在加载页面时绑定了网格。你能分享一些你的代码吗？或者确保你做了绑定，如果！页IsPostback@mwisnicki没错，1/1/1900也在数据库中，你可以把你的代码，显示你如何更新这些数据。我想问题出在你的更新方法上。@Ted你是对的，这里有一个小代码：受保护的无效页面_loadobjectsender，EventArgs e{if！IsPostBack{BindGrid；}很抱歉，我对问题的第一个描述是错误的。请再看一次我的问题，我用图片更新了它。基本上，我只需要在gridview中再次显示数据，如果它不是由用户编辑的，而不是显示1/1/1900。我希望你能帮助我，谢谢~需要从ContractDate==Coalesciv中删除额外的等号签名e更新了AccessLayer更新契约，现在在GridView1_row命令中：否则，如果e.CommandName==UpdateRow，我将其从字符串更改为DateTime DateTime contractDate=TextBoxGridView1.Rows[rowIndex].FindControltxtEditContractDate.Text；及其给我的错误：无法将类型字符串隐式转换为System.DateTime。我想这是因为我在BindGrid中声明了字符串？？有什么想法吗？谢谢大家，请建议其他方法调用SQL语句，而不使用字符串SQL=Select…，请注意，查询具有连接状态T以便我可以将ContractDate称为DateTime。或者您是否有其他建议，感谢我在声明SQL查询以绑定数据时将字符串替换为var。您能告诉我如何将字符串转换为DateTime，如回答中所述^Thank

 public static int UpdateContract(string ContractNo, DateTime? ContractDate, string ContractDuration, string ServiceStart, string ContractDetails, string ContractValue, string Served)
    {
        string css = ConfigurationManager.ConnectionStrings["dbx"].ConnectionString;
        using (SqlConnection con = new SqlConnection(css))
        {
            string UpdateQuery = "UPDATE SCHOLARSHIPCONTRACT SET ContractDate=COALESCE(@ContractDate=ContractDate), ContractDuration = @ContractDuration, ServiceStart = @ServiceStart, ContractDetails = @ContractDetails, ContractValue= @ContractValue, Served = @Served WHERE ContractNo =@ContractNo";
            SqlCommand UpdateCmd = new SqlCommand(UpdateQuery, con);


            UpdateCmd.Parameters.AddWithValue("ContractNo", ContractNo);
            //Here you have to convert string to DateTime
            UpdateCmd.Parameters.AddWithValue("@ContractDate", ContractDate);
            UpdateCmd.Parameters.AddWithValue("@ContractDuration", ContractDuration);
            UpdateCmd.Parameters.AddWithValue("@ServiceStart", ServiceStart);
            UpdateCmd.Parameters.AddWithValue("@ContractDetails", ContractDetails);
            UpdateCmd.Parameters.AddWithValue("@ContractValue", ContractValue);
            UpdateCmd.Parameters.AddWithValue("@Served", Served);

            con.Open();
            return UpdateCmd.ExecuteNonQuery();
        }
    }