FormView.ItemInserting Zdarzenie

Definicja

Występuje po kliknięciu przycisku wstawiania w FormView kontrolce, ale przed operacją wstawiania.Occurs when an Insert button within a FormView control is clicked, but before the insert operation.

public:
 event System::Web::UI::WebControls::FormViewInsertEventHandler ^ ItemInserting;
public event System.Web.UI.WebControls.FormViewInsertEventHandler ItemInserting;
member this.ItemInserting : System.Web.UI.WebControls.FormViewInsertEventHandler 
Public Custom Event ItemInserting As FormViewInsertEventHandler 

Typ zdarzenia

FormViewInsertEventHandler

Przykłady

Poniższy przykład ilustruje sposób użycia ItemInserting zdarzenia w celu anulowania operacji wstawiania.The following example demonstrates how to use the ItemInserting event to cancel an insert operation.


<%@ Page language="C#" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">

  void EmployeeFormView_ItemInserting(Object sender, FormViewInsertEventArgs e)
  {

    MessageLabel.Text = "";

    // Iterate through the items in the Values collection
    // and verify that the user entered a value for each 
    // text box displayed in the insert item template. Cancel
    // the insert operation if the user left a text box empty.
    foreach (DictionaryEntry entry in e.Values)
    {
      if (entry.Value.Equals(""))
      {
        // Use the Cancel property to cancel the 
        // insert operation.
        e.Cancel = true;

        MessageLabel.Text += "Please enter a value for the " +
          entry.Key.ToString() + " field.<br/>";

      }
    }
  }

  void EmployeeFormView_ModeChanged(Object sender, EventArgs e)
  {
    // Clear the MessageLabel Label control when the FormView
    // control changes modes.
    MessageLabel.Text = "";
  }

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>FormViewInsertEventArgs Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>FormViewInsertEventArgs Example</h3>
                       
      <asp:formview id="EmployeeFormView"
        datasourceid="EmployeeSource"
        allowpaging="true"
        datakeynames="EmployeeID"
        emptydatatext="No employees found."
        oniteminserting="EmployeeFormView_ItemInserting"
        onmodechanged="EmployeeFormView_ModeChanged"
        runat="server">

        <itemtemplate>
          <table>
            <tr>
              <td rowspan="5">
                <asp:image id="CompanyLogoImage"
                  imageurl="~/Images/Logo.jpg"
                  alternatetext="Company logo"
                  runat="server"/>
              </td>
              <td colspan="2">
                  &nbsp; 
              </td>
            </tr>
            <tr>
              <td>
                <b>Name:</b>
              </td>
              <td>
                <%# Eval("FirstName") %> <%# Eval("LastName") %>
              </td>
            </tr>
            <tr>
              <td>
                <b>Title:</b>
              </td>
              <td>
                <%# Eval("Title") %>
              </td>
            </tr>
            <tr>
              <td colspan="2">
                <asp:linkbutton id="NewButton"
                  text="New"
                  commandname="New"
                  runat="server"/> 
              </td>
            </tr>
          </table>       
        </itemtemplate>
        <insertitemtemplate>
          <table>
            <tr>
              <td rowspan="4">
                <asp:image id="CompanyLogoEditImage"
                  imageurl="~/Images/Logo.jpg"
                  alternatetext="Company logo"
                  runat="server"/>
              </td>
              <td colspan="2">
                  &nbsp; 
              </td>
            </tr>
            <tr>
              <td>
                <b><asp:Label
                  runat="server" 
                  AssociatedControlID="FirstNameInsertTextBox" 
                  Text="Name" />:</b>
              </td>
              <td>
                <asp:textbox id="FirstNameInsertTextBox"
                  text='<%# Bind("FirstName") %>'
                  runat="server"/>
                <asp:textbox id="LastNameInsertTextBox"
                  text='<%# Bind("LastName") %>'
                  runat="server"/>
              </td>
            </tr>
            <tr>
              <td>
                <b><asp:Label
                  runat="server" 
                  AssociatedControlID="TitleInsertTextBox" 
                  Text="Title" />:</b>
              </td>
              <td>
                <asp:textbox id="TitleInsertTextBox"
                  text='<%# Bind("Title") %>'
                  runat="server"/> 
              </td>
            </tr>
            <tr>
              <td colspan="2">
                <asp:linkbutton id="InsertButton"
                  text="Insert"
                  commandname="Insert"
                  runat="server"/>
                <asp:linkbutton id="CancelButton"
                  text="Cancel"
                  commandname="Cancel"
                  runat="server"/> 
              </td>
            </tr>
          </table>       
        </insertitemtemplate> 
                  
      </asp:formview>
      
      <br/><br/>
      
      <asp:label id="MessageLabel"
        forecolor="Red"
        runat="server"/>

      <!-- This example uses Microsoft SQL Server and connects  -->
      <!-- to the Northwind sample database. Use an ASP.NET     -->
      <!-- expression to retrieve the connection string value   -->
      <!-- from the Web.config file.                            -->
      <asp:sqldatasource id="EmployeeSource"
        selectcommand="Select [EmployeeID], [LastName], [FirstName], [Title], [PhotoPath] From [Employees]"
        insertcommand="Insert Into [Employees] ([LastName], [FirstName], [Title]) VALUES (@LastName, @FirstName, @Title)"
        connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>" 
        runat="server"/>
            
    </form>
  </body>
</html>


<%@ Page language="VB" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">

  Sub EmployeeFormView_ItemInserting(ByVal sender As Object, ByVal e As FormViewInsertEventArgs)

    MessageLabel.Text = ""

    ' Iterate through the items in the Values collection
    ' and verify that the user entered a value for each 
    ' text box displayed in the insert item template. Cancel
    ' the insert operation if the user left a text box empty.
    
    ' In Visual Basic, the DictionaryItem objects contained in 
    ' the Values collection must be copied to an array before
    ' you can iterate through the collection.
    Dim itemArray(e.Values.Count - 1) As DictionaryEntry
    e.Values.CopyTo(itemArray, 0)
    
    Dim entry As DictionaryEntry
    For Each entry In itemArray
    
      If entry.Value.Equals("") Then
      
        ' Use the Cancel property to cancel the 
        ' insert operation.
        e.Cancel = True

        MessageLabel.Text &= "Please enter a value for the " & _
          entry.Key.ToString() & " field.<br/>"
      
      End If
      
    Next
    
  End Sub

  Sub EmployeeFormView_ModeChanged(ByVal sender As Object, ByVal e As EventArgs)
  
    ' Clear the MessageLabel Label control when the FormView
    ' control changes modes.
    MessageLabel.Text = ""
  
  End Sub

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>FormViewInsertEventArgs Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>FormViewInsertEventArgs Example</h3>
                       
      <asp:formview id="EmployeeFormView"
        datasourceid="EmployeeSource"
        allowpaging="true"
        datakeynames="EmployeeID"
        emptydatatext="No employees found."
        oniteminserting="EmployeeFormView_ItemInserting"
        onmodechanged="EmployeeFormView_ModeChanged"
        runat="server">

        <itemtemplate>
          <table>
            <tr>
              <td rowspan="5">
                <asp:image id="CompanyLogoImage"
                  imageurl="~/Images/Logo.jpg"
                  alternatetext="Company logo"
                  runat="server"/>
              </td>
              <td colspan="2">
                  &nbsp; 
              </td>
            </tr>
            <tr>
              <td>
                <b>Name:</b>
              </td>
              <td>
                <%# Eval("FirstName") %> <%# Eval("LastName") %>
              </td>
            </tr>
            <tr>
              <td>
                <b>Title:</b>
              </td>
              <td>
                <%# Eval("Title") %>
              </td>
            </tr>
            <tr>
              <td colspan="2">
                <asp:linkbutton id="NewButton"
                  text="New"
                  commandname="New"
                  runat="server"/> 
              </td>
            </tr>
          </table>       
        </itemtemplate>
        <insertitemtemplate>
          <table>
            <tr>
              <td rowspan="4">
                <asp:image id="CompanyLogoEditImage"
                  imageurl="~/Images/Logo.jpg"
                  alternatetext="Company logo"
                  runat="server"/>
              </td>
              <td colspan="2">
                  &nbsp; 
              </td>
            </tr>
            <tr>
              <td>
                <b><asp:Label
                  runat="server" 
                  AssociatedControlID="FirstNameInsertTextBox" 
                  Text="Name" />:</b>
              </td>
              <td>
                <asp:textbox id="FirstNameInsertTextBox"
                  text='<%# Bind("FirstName") %>'
                  runat="server"/>
                <asp:textbox id="LastNameInsertTextBox"
                  text='<%# Bind("LastName") %>'
                  runat="server"/>
              </td>
            </tr>
            <tr>
              <td>
                <b><asp:Label
                  runat="server" 
                  AssociatedControlID="TitleInsertTextBox" 
                  Text="Title" />:</b>
              </td>
              <td>
                <asp:textbox id="TitleInsertTextBox"
                  text='<%# Bind("Title") %>'
                  runat="server"/> 
              </td>
            </tr>
            <tr>
              <td colspan="2">
                <asp:linkbutton id="InsertButton"
                  text="Insert"
                  commandname="Insert"
                  runat="server"/>
                <asp:linkbutton id="CancelButton"
                  text="Cancel"
                  commandname="Cancel"
                  runat="server"/> 
              </td>
            </tr>
          </table>       
        </insertitemtemplate> 
                  
      </asp:formview>
      
      <br/><br/>
      
      <asp:label id="MessageLabel"
        forecolor="Red"
        runat="server"/>

      <!-- This example uses Microsoft SQL Server and connects  -->
      <!-- to the Northwind sample database. Use an ASP.NET     -->
      <!-- expression to retrieve the connection string value   -->
      <!-- from the Web.config file.                            -->
      <asp:sqldatasource id="EmployeeSource"
        selectcommand="Select [EmployeeID], [LastName], [FirstName], [Title], [PhotoPath] From [Employees]"
        insertcommand="Insert Into [Employees] ([LastName], [FirstName], [Title]) VALUES (@LastName, @FirstName, @Title)"
        connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>" 
        runat="server"/>
            
    </form>
  </body>
</html>

Uwagi

FormViewKontrolka wywołuje ItemInserting zdarzenie, gdy kliknięto przycisk Wstaw (przycisk z CommandName właściwością ustawioną na "INSERT") wewnątrz kontrolki, ale przed FormView wstawieniem rekordu przez formant.The FormView control raises the ItemInserting event when an Insert button (a button with its CommandName property set to "Insert") within the control is clicked, but before the FormView control inserts the record. Dzięki temu można podać metodę obsługi zdarzeń, która wykonuje procedurę niestandardową, taką jak kodowanie HTML wartości rekordu przed wstawieniem go do źródła danych, gdy wystąpi zdarzenie.This allows you to provide an event-handling method that performs a custom routine, such as HTML encoding the values of a record before inserting it in the data source, whenever this event occurs.

FormViewInsertEventArgsObiekt jest przekazywany do metody obsługi zdarzeń, co pozwala określić wartość opcjonalnego argumentu polecenia wysłanego do FormView kontrolki i wskazać, że operacja wstawiania powinna zostać anulowana.A FormViewInsertEventArgs object is passed to the event-handling method, which allows you to determine the value of an optional command argument sent to the FormView control and to indicate that the insert operation should be canceled. Wartość argumentu polecenia odpowiada CommandArgument Właściwości przycisku wstawiania.The command argument value corresponds to the CommandArgument property of the Insert button. Po CommandArgument ustawieniu właściwości przycisku Wstaw Użyj CommandArgument właściwości, aby określić wartość argumentu polecenia.When the CommandArgument property of the Insert button is set, use the CommandArgument property to determine the value of the command argument. Aby anulować operację wstawiania, należy ustawić Cancel Właściwość na true .To cancel the insert operation, set the Cancel property to true. Możesz również odczytać lub zmodyfikować wartości pól dla nowego rekordu przy użyciu Values właściwości.You can also read or modify the field values for the new record by using the Values property.

Aby uzyskać więcej informacji o sposobie obsługi zdarzeń, zobacz Obsługa iwywoływanie zdarzeń.For more information about how to handle events, see Handling and Raising Events.

Dotyczy

Zobacz też