向數據表添加新行

Question

我的表單中有一個GeidView，還有一個按鈕，該按鈕通過向Datatable添加一行來向GridView添加新記錄，然后將該數據表作為GridContol的數據源。

問題是當我添加一條新記錄時，它顯示在GridView中，但是當我添加另一個記錄時，它不在GridView中顯示，該GridView始終包含我添加到DataTable中的第一行！

所以，請您能幫我解決這個問題嗎？

這是源代碼：

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(); 。 這將覆蓋更改並重新創建數據表值

在頁面回發時，變量將恢復為其默認值，並且需要重新創建它們。 您可以使用會話來維護您的價值觀

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;
   }
}

並檢索會話保留的值

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

改變你的

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;
    }

您還必須將數據表保存到會話

Answer 3

recmpensesTable始終是一個新的DateTable，您應將其保存到會話中以備下次使用。