在ASP.NET中使用datatable [英] Using datatable in ASP.NET

问题描述

大家好，

我有一个asp.net数据输入页面，每次用户点击按钮时，刚输入的数据将被保存在临时数据表中，然后才能实际发送到后端。代码如下：

  Imports  System.Data。 SqlClient 
 
 公共 类 dt 
  Inherits  System.Web.UI.Page 
 
  Dim  ds 正如 新 dsAster 
 
  Dim  dtable  As  DataTable 
  Dim  r  As  DataRow 
 
 受保护的  Sub  Page_Load（ ByVal  sender 作为 对象， ByVal  e  As  System.EventArgs）句柄 我 .Load 
 
 
 结束  Sub  
 
 受保护的  Sub  Button2_Click（发件人作为 对象，e  As  EventArgs）句柄 Button2.Click 
 
 
 dtable = ds.Tables（  dt1）
 
r = dtable.NewRow 
 
r（   col1）= 我 .TextBox1 .Text 
r（  col2）=    string = +  Me  .TextBox2.Text.ToString 
 
 dtable.Rows.Add（r）
 
  Me  .DataList1.DataSource = dtable 
 < span class =code-keyword> Me  .DataList1.DataBind（）

现在问题是每次用户单击保存按钮，它将覆盖之前输入的按钮。简而言之，DataTable只包含最后输入的记录。我需要的是新记录将附加到数据表。

我认为这是因为每次页面加载时都会创建数据表。



我尝试了什么：



我的想法是不重新创建数据表，如果它不是回发，所以我将声明部分移动到如果不是ispostback中的page_load ...结束if block，但这将使任何vars声明post page_load将无法识别。请帮忙。这两天我一直在拉我的头发:(

谢谢大家。

解决方案

我建​​议你保留 DataTable 在会话中并在更新表格之前检查会话可用性。



当您检查是否存在时，您可以轻松地从会话获取数据，然后更新表并将其分配回会话。

Hi all,
I have an asp.net data entry page, and everytime the user click button the data just entered will be saved in a temp datatable before actually send to the backend. The code is following:

Imports System.Data.SqlClient

Public Class dt
    Inherits System.Web.UI.Page

            Dim ds As New dsAster

            Dim dtable As DataTable
            Dim r As DataRow

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load


    End Sub

Protected Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click


        dtable = ds.Tables("dt1")

        r = dtable.NewRow

        r("col1") = Me.TextBox1.Text
        r("col2") = "string=" + Me.TextBox2.Text.ToString

        dtable.Rows.Add(r)

        Me.DataList1.DataSource = dtable
        Me.DataList1.DataBind()

Now the prob is everytime the user click the save button, it will override the one that entered previously. In short, the DataTable will only contain last entered record. What i require is new records will be appended to the datatable.
I think it's because the datatable got created everytime the page load.

What I have tried:

My idea is to not to recreate the datatable if it's not a postback, so I move the declaration portion into page_load in a if not ispostback...end if block, but that will make any vars declare post page_load will not be recognised. Pls help. I've been pulling my hair these past 2 days :(
Thanks guys.

解决方案

I would suggest you to keep the DataTable in Session and check the Session availability before updating the table.

When you check if that is present, after that you can easily get data from Session and then update the table and assign it back to Session.

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