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FormView.ItemInserting Událost

Definice

Vyvolá se při kliknutí na tlačítko Vložit v rámci FormView ovládacího prvku, ale před operací vložení.

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 

Event Type

Příklady

Následující příklad ukazuje, jak použít ItemInserting událost ke zrušení operace vložení.


<%@ 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">
                    
              </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">
                    
              </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">
                    
              </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">
                    
              </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>

Poznámky

Ovládací FormView prvek vyvolá ItemInserting událost při kliknutí na tlačítko Vložit (tlačítko s CommandName jeho vlastností nastavenou na "Vložit") v rámci ovládacího prvku, ale předtím, než FormView ovládací prvek vloží záznam. To vám umožní poskytnout metodu zpracování událostí, která provádí vlastní rutinu, například kódování HTML hodnoty záznamu před jeho vložením do zdroje dat, kdykoli dojde k této události.

FormViewInsertEventArgs Objekt je předán metodě zpracování událostí, která umožňuje určit hodnotu volitelného argumentu příkazu odeslaného FormView ovládacímu prvku a označit, že operace vložení by měla být zrušena. Hodnota argumentu CommandArgument příkazu odpovídá vlastnosti tlačítka Vložit. Pokud je nastavena CommandArgument vlastnost tlačítka Insert, použijte CommandArgument vlastnost k určení hodnoty argumentu příkazu. Pokud chcete operaci vložení zrušit, nastavte Cancel vlastnost na true. Pomocí vlastnosti můžete také číst nebo upravovat hodnoty polí pro nový záznam Values .

Další informace o zpracování událostí najdete v tématu Zpracování a vyvolávání událostí.

Platí pro

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