向数据表添加新行

Question

我的表单中有一个GeidView，还有一个按钮，该按钮通过向Datatable添加一行来向GridView添加新记录，然后将该数据表作为GridContol的数据源。

问题是当我添加一条新记录时，它显示在GridView中，但是当我添加另一个记录时，它不在GridView中显示，该GridView始终包含我添加到DataTable中的第一行！

所以，请您能帮我解决这个问题吗？

这是源代码：

private DataTable recompensesTable;

private void AjoutLivre_Load(object sender, EventArgs e)
        {
          recompensesTable = MakeRecomponsesTable();
          recompenseGridControl.DataSource = recompensesTable;
        }
private DataTable MakeRecomponsesTable()
        {
            DataTable recmpensesTable = new DataTable("Recompenses");

            var anneeColumn = new DataColumn();
            anneeColumn.DataType = Type.GetType("System.Int32");
            anneeColumn.ColumnName = "Année";
            recmpensesTable.Columns.Add(anneeColumn);

            var prixLiteraireColumn = new DataColumn();
            prixLiteraireColumn.DataType = Type.GetType("System.String");
            prixLiteraireColumn.ColumnName = "Prix Litéraire";
            recmpensesTable.Columns.Add(prixLiteraireColumn);

            return recmpensesTable;
        }

private void nouveauRecompense_Click(object sender, EventArgs e)
        {
            DataRow row = recompensesTable.NewRow();

            row[0] = ajoutRecompense.KeyWordAnnee;
            row[1] = ajoutRecompense.KeyWordPrixLiteraire;
            recompensesTable.Rows.Add(row);

            recompenseGridControl.DataSource = recompensesTable;
        }

Answer 1

在您的Page_Load中，您有recompensesTable = MakeRecomponsesTable(); 。 这将覆盖更改并重新创建数据表值

在页面回发时，变量将恢复为其默认值，并且需要重新创建它们。 您可以使用会话来维护您的价值观

private void AjoutLivre_Load(object sender, EventArgs e)
{
   if(!Page.IsPostBack)
   {
     DataTable recompensesTable = MakeRecomponsesTable();
     Session["recompensesTable"] = recompensesTable; //Save it to session the first time
     recompenseGridControl.DataSource = recompensesTable;
   }
}

并检索会话保留的值

private void nouveauRecompense_Click(object sender, EventArgs e)
{
    DataTable recompensesTable = (DataTable) Session["recompensesTable"]; //retrieve it from session
    DataRow row =  recompensesTable.NewRow();

    row[0] = ajoutRecompense.KeyWordAnnee;
    row[1] = ajoutRecompense.KeyWordPrixLiteraire;
    recompensesTable.Rows.Add(row);

    Session["recompensesTable"] = recompensesTable; //save it back to session

    recompenseGridControl.DataSource = recompensesTable;
}

Answer 2

改变你的

private void AjoutLivre_Load(object sender, EventArgs e)
    {
      recompensesTable = MakeRecomponsesTable();
      recompenseGridControl.DataSource = recompensesTable;
    }

至

private void AjoutLivre_Load(object sender, EventArgs e)
    {
      if(!IsPostback)
         recompensesTable = MakeRecomponsesTable();
      recompenseGridControl.DataSource = recompensesTable;
    }

您还必须将数据表保存到会话

Answer 3

recmpensesTable始终是一个新的DateTable，您应将其保存到会话中以备下次使用。