Как показать уникальное ключевое исключение перед сохранением в базе данных?

Question

Я создал сетку, в которой пользователь может вводить элементы и их количества. Количество элементов неизвестно, поэтому требование заключалось в том, что можно добавить столько элементов, которые хотят пользователи. Поэтому я дал положение о добавлении строки позиции для другой записи. Все эти введенные данные попадают во временную таблицу, и все делается щелчком по кнопке, все эти данные будут сохраняться в базе данных.

Есть ли способ скрыть элементы, которые уже были выбраны в предыдущей строке, или показать сообщение об ошибке, которое элемент уже вводил при выборе значения выпадающего списка, прежде чем нажимать на кнопку.

Моя GridView выглядит примерно так:

GridView код: за

<asp:GridView ID="gvItemList" runat="server" AutoGenerateColumns="False" AutoGenerateDeleteButton="True" BackColor="#CCCCCC" BorderColor="#999999" BorderStyle="Solid" BorderWidth="3px" CellPadding="4" CellSpacing="2" CssClass="newStyle9" ForeColor="Black" OnRowDataBound="gvItemList_RowDataBound" OnRowDeleting="gvItemList_RowDeleting" ShowFooter="True" style="text-align: center" ViewStateMode="Enabled"> 
           <Columns> 
            <asp:TemplateField HeaderText="Sl No" SortExpression="Id"> 
             <ItemTemplate> 
              <asp:Label ID="lblId" runat="server" Text="<%# Container.DataItemIndex+1 %>"></asp:Label> 
             </ItemTemplate> 
            </asp:TemplateField> 
            <asp:TemplateField HeaderText="Item Description"> 
             <ItemTemplate> 
              <asp:DropDownList ID="ddlItem" runat="server" Height="25px" Width="200px" AutoPostBack="True" OnSelectedIndexChanged="ddlItem_SelectedIndexChanged"> 
              </asp:DropDownList> 
             </ItemTemplate> 
            </asp:TemplateField> 
            <asp:TemplateField HeaderText="Unit"> 
             <ItemTemplate> 
              <asp:Label ID="txtUnit" runat="server"></asp:Label> 
             </ItemTemplate> 
            </asp:TemplateField> 
            <asp:TemplateField HeaderText="Quantity"> 
             <ItemTemplate> 
              <asp:TextBox ID="txtQty" runat="server" Height="27px" Width="73px"></asp:TextBox> 
             </ItemTemplate> 
             <FooterStyle HorizontalAlign="Right" /> 
             <FooterTemplate> 
              <asp:Button ID="AddRowButton" runat="server" OnClick="ButtonAdd_Click" Text="Add New Item" /> 
             </FooterTemplate> 
            </asp:TemplateField> 
           </Columns> 
           <FooterStyle BackColor="#CCCCCC" /> 
           <HeaderStyle BackColor="Black" Font-Bold="True" ForeColor="White" /> 
           <PagerStyle BackColor="#CCCCCC" ForeColor="Black" HorizontalAlign="Left" /> 
           <RowStyle BackColor="White" /> 
           <SelectedRowStyle BackColor="#000099" Font-Bold="True" ForeColor="White" /> 
           <SortedAscendingCellStyle BackColor="#F1F1F1" /> 
           <SortedAscendingHeaderStyle BackColor="#808080" /> 
           <SortedDescendingCellStyle BackColor="#CAC9C9" /> 
           <SortedDescendingHeaderStyle BackColor="#383838" /> 
          </asp:GridView> 

Код:

private void SetInitialRowToGrid() 
    { 
     // Initialize and Set initial row of Datatable 
     var tempDataTable = new DataTable(); 
     tempDataTable.Columns.Add("lblId"); 
     tempDataTable.Columns.Add("ddlItem"); 
     tempDataTable.Columns.Add("txtUnit"); 
     tempDataTable.Columns.Add("txtQty");   
     tempDataTable.Rows.Add("1", "", "", ""); 

     // Store that datatable into viewstate 
     ViewState["TempTable"] = tempDataTable; 

     // Attach Gridview Datasource to datatable   
     gvItemList.DataSource = tempDataTable; 
     gvItemList.DataBind(); 
    } 
    private void AddNewRowToGrid() 
    { 
     int rowIndex = 0; 

     if (ViewState["TempTable"] != null) 
     { 
      // Get TempTable from viewstate 
      var tempTable = (DataTable)ViewState["TempTable"]; 
      DataRow tempRow = null; 

      if (tempTable.Rows.Count > 0) 
      { 
       for (int i = 1; i <= tempTable.Rows.Count; i++) 
       { 
        // Get Grid's values 
        var Item = 
         (DropDownList)gvItemList.Rows[rowIndex].Cells[2].FindControl("ddlItem"); 
        var Unit = 
         (Label)gvItemList.Rows[rowIndex].Cells[3].FindControl("txtUnit"); 
        var Qty = 
         (TextBox)gvItemList.Rows[rowIndex].Cells[4].FindControl("txtQty"); 


        // Create new row and update Row Number 
        tempRow = tempTable.NewRow(); 

        tempTable.Rows[i - 1]["ddlItem"] = Item.SelectedValue; 
        tempTable.Rows[i - 1]["txtUnit"] = Unit.Text; 
        tempTable.Rows[i - 1]["txtQty"] = Qty.Text;      
        rowIndex++; 
       } 

       // Add data to datatable and viewstate 
       tempTable.Rows.Add(tempRow); 
       ViewState["TempTable"] = tempTable; 

       // Attach Gridview Datasource to datatable 
       gvItemList.DataSource = tempTable; 
       gvItemList.DataBind(); 
      } 
     } 

     //Set Previous Data on Postbacks 
     SetPreviousData(); 
    } 

    private void SetPreviousData() 
    { 
     int rowIndex = 0; 

     if (ViewState["TempTable"] != null) 
     { 
      var tempTable = (DataTable)ViewState["TempTable"]; 

      if (tempTable.Rows.Count > 0) 
      { 
       for (int i = 0; i < tempTable.Rows.Count; i++) 
       { 
        var Item = 
         (DropDownList)gvItemList.Rows[rowIndex].Cells[2].FindControl("ddlItem"); 
        var Unit = 
         (Label)gvItemList.Rows[rowIndex].Cells[3].FindControl("txtUnit"); 
        var Qty = 
         (TextBox)gvItemList.Rows[rowIndex].Cells[4].FindControl("txtQty"); 


        Item.SelectedValue = tempTable.Rows[i]["ddlItem"].ToString(); 
        Unit.Text = tempTable.Rows[i]["txtUnit"].ToString(); 
        Qty.Text = tempTable.Rows[i]["txtQty"].ToString();     

        rowIndex++; 
       } 
      } 
     } 
    } 
    protected void ButtonAdd_Click(object sender, EventArgs e) 
    { 
     AddNewRowToGrid(); 
    } 
    protected void gvItemList_RowDeleting(object sender, GridViewDeleteEventArgs e) 
    { 
     int index = Convert.ToInt32(e.RowIndex); 

     deleteRow(index); 
     SetPreviousData();   

     if (gvItemList.Rows.Count == 0) 
     { 
      SetInitialRowToGrid(); 
     } 
    } 
    private int deleteRow(int index) 
    { 
     int rowIndex = 0; 

     if (ViewState["TempTable"] != null) 
     { 
      // Get TempTable from viewstate 
      var tempTable = (DataTable)ViewState["TempTable"]; 


      if (tempTable.Rows.Count > 0) 
      { 
       for (int i = 1; i <= tempTable.Rows.Count; i++) 
       { 
        // Get Grid's TextBox values 
        var Item = 
         (DropDownList)gvItemList.Rows[rowIndex].Cells[2].FindControl("ddlItem"); 
        var Unit = 
         (Label)gvItemList.Rows[rowIndex].Cells[3].FindControl("txtUnit"); 
        var Qty = 
         (TextBox)gvItemList.Rows[rowIndex].Cells[4].FindControl("txtQty"); 
       } 

       // Add data to datatable and viewstate     
       tempTable.Rows.RemoveAt(index); 
       ViewState["TempTable"] = tempTable; 

       // Attach Gridview Datasource to datatable 
       gvItemList.DataSource = tempTable; 
       gvItemList.DataBind(); 
      } 
     } 

     //Set Previous Data on Postbacks   
     return index; 
    } 

    protected void gvItemList_RowDataBound(object sender, GridViewRowEventArgs e) 
    { 
     if (e.Row.RowType == DataControlRowType.DataRow) 
     { 
      DropDownList ddlItem = (e.Row.FindControl("ddlItem") as DropDownList); 
      Jilu1TableAdapters.tbl_ItemTableAdapter item; 
      item = new Jilu1TableAdapters.tbl_ItemTableAdapter(); 
      DataTable dt = new DataTable(); 
      dt = item.GetItems(); 

      ddlItem.DataSource = dt; 
      ddlItem.DataTextField = "Item"; 
      ddlItem.DataValueField = "Item"; 
      ddlItem.DataBind(); 
      ddlItem.Items.Insert(0, new System.Web.UI.WebControls.ListItem("--Select an Item--", "0")); 
     } 
    } 
    private void InsertRecords(StringCollection sc) 
    { 
     Jilu1TableAdapters.tbl_Jr_BOMTableAdapter ds; 
     ds = new Jilu1TableAdapters.tbl_Jr_BOMTableAdapter(); 

     StringBuilder sb = new StringBuilder(string.Empty); 
     string[] splitItems = null; 
     string user = Page.User.Identity.Name; 

     try 
     { 
      foreach (string item in sc) 
      { 


       if (item.Contains(",,,")) 
       { 
        //To prevent null reference error 
       } 
       else 
       { 
        splitItems = item.Split(",".ToCharArray()); 
        ds.InsertJrBOM(ddlState.SelectedValue, ddlDistrict.SelectedValue, ddlCluster.SelectedValue, ddlSiteID.SelectedValue, txtSiteName.Text, ddlSiteType.SelectedValue, txtNoBTS.Text, txtNoLinks.Text, txtLoadBand.Text, ddlEBAvailability.SelectedValue, txtEBPhase.Text, txtDGCapacity.Text, txtDGPhase.Text, splitItems[0], splitItems[1], splitItems[2], user, DateTime.Now, "Nil", 1, txtDispatch.Text); 

       } 

      } 
      lblSuccess.Visible = true; 
      lblSuccess.Text = "Records Successfully Saved!"; 
      Timer1.Enabled = true; 
     } 
     catch (System.Data.SqlClient.SqlException) 
     { 
      lblErrorMessage.Visible = true; 
      lblErrorMessage.Text = "Duplicate Items has been entered, please correct it before proceeding or an entry for " + ddlSiteID.Text + " has already made, please go to edit page to make necessary changes!"; 
      Timer1.Enabled = true; 
      return; 
     } 
     catch (Exception ex) 
     { 
      lblErrorMessage.Visible = true; 
      lblErrorMessage.Text = "Error: " + ex.Message; 
      Timer1.Enabled = true; 
     }   

    }  
    protected void btnAdd_Click(object sender, EventArgs e) 
    { 
     int rowIndex = 0; 
     StringCollection sc = new StringCollection(); 
     if (ViewState["TempTable"] != null) 
     { 

      DataTable dtCurrentTable = (DataTable)ViewState["TempTable"]; 
      if (dtCurrentTable.Rows.Count > 0) 
      { 
       for (int i = 1; i <= dtCurrentTable.Rows.Count; i++) 
       { 
        //extract the TextBox values 
        DropDownList ddlItem = (DropDownList)gvItemList.Rows[rowIndex].Cells[2].FindControl("ddlItem"); 
        Label txtUnit = (Label)gvItemList.Rows[rowIndex].Cells[3].FindControl("txtUnit"); 
        TextBox txtQty = (TextBox)gvItemList.Rows[rowIndex].Cells[4].FindControl("txtQty"); 

        //get the values from the TextBoxes 
        //then add it to the collections with a comma "," as the delimited values 
        sc.Add(ddlItem.SelectedValue + "," + txtUnit.Text + "," + txtQty.Text); 
        if (sc.Contains(",,,")) 
        { 
         lblErrorMessage.Visible = true; 
         lblErrorMessage.Text = "Fields should not be left empty!"; 
         Timer1.Enabled = true; 
         return; 
        } 
        else 
        { 
         string Quantity = txtQty.Text; 
         float num; 
         if (float.TryParse(Quantity, out num)) 
         { 
          rowIndex++; 
         } 
         else 
         { 
          lblErrorMessage.Visible = true; 
          lblErrorMessage.Text = "Quantity field must be a number!"; 
          Timer1.Enabled = true; 
          return; 
         } 
        } 
       } 
       //Call the method for executing inserts 
       InsertRecords(sc); 
       if (lblSuccess.Text == "Records Successfully Saved!") 
       { 
        this.SetInitialRowToGrid(); 
        string user = Page.User.Identity.Name; 
        StatusTableAdapters.tbl_NotificationsTableAdapter ds2; 
        ds2 = new StatusTableAdapters.tbl_NotificationsTableAdapter(); 

        ds2.InsertNotification(ddlSiteID.SelectedValue, "BOM Notification", DateTime.Now, user, "Role6"); 

       } 
      } 
     } 
    } 

Любая помощь будет принята с благодарностью.

Answer 1

protected void ddlItem_SelectedIndexChanged(object sender, EventArgs e) 
{ 
    var main = (sender as DropDownList); 

    foreach (GridViewRow row in gvItemList.Rows) 
    { 
      var ddl = (row.FindControl("ddlItem") as DropDownList); 

      if (main.ClientID != ddl.ClientID && ddl.SelectedValue == main.SelectedValue) 
      { 
       row.BackColor = System.Drawing.Color.Red; 
       string script = "alert('already selected!');"; 
       ScriptManager.RegisterStartupScript(this, GetType(), 
        "ServerControlScript", script, true); 
      } 
    }   
}