FormViewInsertEventHandler Делегат

Определение

Представляет метод, обрабатывающий событие ItemInserting элемента управления FormView.Represents the method that handles the ItemInserting event of a FormView control.

public delegate void FormViewInsertEventHandler(System::Object ^ sender, FormViewInsertEventArgs ^ e);
public delegate void FormViewInsertEventHandler(object sender, FormViewInsertEventArgs e);
type FormViewInsertEventHandler = delegate of obj * FormViewInsertEventArgs -> unit
Public Delegate Sub FormViewInsertEventHandler(sender As Object, e As FormViewInsertEventArgs)

Параметры

sender
Object

Источник события.The source of the event.

e
FormViewInsertEventArgs

Объект FormViewInsertEventArgs, содержащий данные события.A FormViewInsertEventArgs that contains the event data.

Наследование
FormViewInsertEventHandler

Примеры

В следующем примере показано, как программным способом FormViewInsertEventHandler добавить делегат ItemInserting к событию FormView элемента управления.The following example demonstrates how to programmatically add a FormViewInsertEventHandler delegate to the ItemInserting event of a FormView control.


<%@ Page language="C#" %>
<%@ import namespace="System.Data"%>

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

  // To dynamically create a template for a FormView control,
  // you must create a custom template class to represent 
  // the template. This template class represents the item
  // template for a FormView control.
  private sealed class EmployeeItemTemplate : ITemplate
  {

    // When implementing the ITemplate interface, you must
    // implement the InstantiateIn method. The FormView
    // control calls this method to create the template's 
    // content. 
    void ITemplate.InstantiateIn(Control container)
    {
      // Create the child controls contained in the template.
      // For this example, the item template displays the
      // FirstName and LastName fields from the data source.
      // To support data binding, create event handlers 
      // for the DataBinding event of each child control.
      // The event handlers must bind the appropriate value 
      // to each control.
      Label firstNameLabel = new Label();
      firstNameLabel.ID = "FirstNameLabel";
      firstNameLabel.DataBinding += new EventHandler(FirstNameLabel_DataBinding);

      LiteralControl nameLineBreak = new LiteralControl("<br/>");
      LiteralControl buttonLineBreak = new LiteralControl("<br/>");

      Label lastNameLabel = new Label();
      lastNameLabel.ID = "LastNameLabel";
      lastNameLabel.DataBinding += new EventHandler(LastNameLabel_DataBinding);

      Button newButton = new Button();
      newButton.ID = "NewButton";
      newButton.CommandName = "New";
      newButton.Text = "New";

      // Add the controls to the Controls collection of the 
      // container control.
      container.Controls.Add(firstNameLabel);
      container.Controls.Add(nameLineBreak);
      container.Controls.Add(lastNameLabel);
      container.Controls.Add(buttonLineBreak);
      container.Controls.Add(newButton);

    }

    // This event handler binds the value of the FirstName field
    // to the FirstNameLabel Label control displayed in the template.
    private void FirstNameLabel_DataBinding(Object sender, EventArgs e)
    {
      // Use the sender parameter to retrieve the Label control
      // being bound to data.
      Label firstNameLabelControl = (Label)sender;

      // Retrieve the value to bind to the Label control. First,
      // use the NamingContainer property to retrieve the parent 
      // control of the Label control. In this example, the parent 
      // control is the FormView control.
      FormView formViewContainer = (FormView)firstNameLabelControl.NamingContainer;

      // Get the data item bound to the FormView control.
      DataRowView rowView = (DataRowView)formViewContainer.DataItem;

      // Use the data item to retrieve the value of the FirstName field.
      // Set the Text property of the Label control to this value.        
      firstNameLabelControl.Text = rowView["FirstName"].ToString();
    }

    // This event handler binds the value of the LastName field
    // to the LastNameLabel Label control displayed in the template.
    private void LastNameLabel_DataBinding(Object sender, EventArgs e)
    {
      // Use the sender parameter to retrieve the Label control
      // being bound to data.
      Label lastNameLabelControl = (Label)sender;

      // Retrieve the value to bind to the Label control. First,
      // use the NamingContainer property to retrieve the parent 
      // control of the Label control. In this example, the parent 
      // control is the FormView control.
      FormView formViewContainer = (FormView)lastNameLabelControl.NamingContainer;

      // Get the data item bound to the FormView control.
      DataRowView rowView = (DataRowView)formViewContainer.DataItem;

      // Use the data item to retrieve the value of the LastName field.
      // Set the Text property of the Label control to this value.         
      lastNameLabelControl.Text = rowView["LastName"].ToString();
    }

  }
  
  // This template class represents the insert item
  // template for a FormView control.
  private sealed class EmployeeInsertItemTemplate : ITemplate
  {

    void ITemplate.InstantiateIn(Control container)
    {
      // Create the child controls contained in the template.
      // The insert item template should contain the input 
      // controls for the user to enter a record.
      TextBox firstNameTextBox = new TextBox();
      firstNameTextBox.ID = "FirstNameTextBox";

      LiteralControl nameLineBreak = new LiteralControl("<br/>");
      LiteralControl buttonLineBreak = new LiteralControl("<br/>");

      TextBox lastNameTextBox = new TextBox();
      lastNameTextBox.ID = "LastNameTextBox";

      Button insertButton = new Button();
      insertButton.ID = "InsertButton";
      insertButton.CommandName = "Insert";
      insertButton.Text = "Insert";

      Button cancelButton = new Button();
      cancelButton.ID = "CancelButton";
      cancelButton.CommandName = "Cancel";
      cancelButton.Text = "Cancel";

      // Add the controls to the Controls collection of the 
      // container control.
      container.Controls.Add(firstNameTextBox);
      container.Controls.Add(nameLineBreak);
      container.Controls.Add(lastNameTextBox);
      container.Controls.Add(buttonLineBreak);
      container.Controls.Add(insertButton);
      container.Controls.Add(cancelButton);

    }
  }

  void Page_Load(Object sender, EventArgs e)
  {

    // Create a new FormView object.
    FormView employeesFormView = new FormView();

    // Set the FormView object's properties.
    employeesFormView.ID = "EmployeesFormView";
    employeesFormView.DataSourceID = "EmployeeSource";
    employeesFormView.AllowPaging = true;
    employeesFormView.HeaderText = "Employee Name";
    employeesFormView.DataKeyNames = new String[1] { "EmployeeID" };

    // Programmatically register the event handlers for the 
    // the FormView control.
    employeesFormView.ItemInserted += new FormViewInsertedEventHandler(EmployeeFormView_ItemInserted);
    employeesFormView.ItemInserting += new FormViewInsertEventHandler(EmployeeFormView_ItemInserting);

    // Create the dynamic templates using the custom template classes.
    employeesFormView.ItemTemplate = new EmployeeItemTemplate();
    employeesFormView.InsertItemTemplate = new EmployeeInsertItemTemplate();
    
    // Add the FormView object to the Controls collection
    // of the PlaceHolder control.
    FormViewPlaceHolder.Controls.Add(employeesFormView);

  }

  void EmployeeFormView_ItemInserting(Object sender, FormViewInsertEventArgs e)
  {
    
    // Because the FormView control is dynamically generated, 
    // the Values collection must be programmatically populated
    // with the values for the record to insert.

    // Use the sender argument to retrieve the FormView
    // control that raised the event.
    FormView employeeFormView = (FormView)sender;
    
    // Retrieve the data row from the FormView control.
    FormViewRow row = employeeFormView.Row;

    // Retrieve the TextBox controls that contain the values 
    // entered by the user for the new record. 
    TextBox firstNameTextBox = (TextBox)row.FindControl("FirstNameTextBox");
    TextBox lastNameTextBox = (TextBox)row.FindControl("LastNameTextBox");

    if (firstNameTextBox != null && lastNameTextBox != null)
    {
      // Add the new values to the Values collections.
      e.Values.Add("FirstName", firstNameTextBox.Text);
      e.Values.Add("LastName", lastNameTextBox.Text);
    }

  }

  void EmployeeFormView_ItemInserted(Object sender, FormViewInsertedEventArgs e)
  {
    // Use the Exception property to determine whether an exception
    // occurred during the insert operation.
    if (e.Exception == null)
    {
      // Use the AffectedRows property to determine whether the
      // record was inserted. Sometimes an error might occur that 
      // does not raise an exception, but prevents the insert
      // operation from completing.
      if (e.AffectedRows == 1)
      {
        MessageLabel.Text = "Record inserted successfully.";
      }
      else
      {
        MessageLabel.Text = "An error occurred during the insert operation.";
        
        // Use the KeepInInsertMode property to keep the control in 
        // insert mode when an error occurs during the insert operation.
        e.KeepInInsertMode = true;
      }
    }
    else
    {
      // Insert the code to handle the exception.
      MessageLabel.Text = e.Exception.Message;
      
      // Use the ExceptionHandled property to indicate that the 
      // exception has already been handled.
      e.ExceptionHandled = true;
      e.KeepInInsertMode = true;
    }
  }

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>FormView Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>FormView Example</h3>
      
      <!-- Use a PlaceHolder control as the container for the -->
      <!-- dynamically generated FormView control.            -->       
      <asp:placeholder id="FormViewPlaceHolder"
        runat="server"/>
      
      <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] From [Employees]"
        insertcommand="Insert Into [Employees] ([LastName], [FirstName]) VALUES (@LastName, @FirstName)"
        connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>" 
        runat="server"/>
            
    </form>
  </body>
</html>


<%@ Page language="VB" %>
<%@ import namespace="System.Data"%>

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

  ' To dynamically create a template for a FormView control,
  ' you must create a custom template class to represent 
  ' the template. This template class represents the item
  ' template for a FormView control.
  Private NotInheritable Class EmployeeItemTemplate
    Implements ITemplate

    ' When implementing the ITemplate interface, you must
    ' implement the InstantiateIn method. The FormView
    ' control calls this method to create the template's 
    ' content. 
    Sub InstantiateIn(ByVal container As Control) Implements ITemplate.InstantiateIn
      
      ' Create the child controls contained in the template.
      ' For this example, the item template displays the
      ' FirstName and LastName fields from the data source.
      ' To support data binding, create event handlers 
      ' for the DataBinding event of each child control.
      ' The event handlers must bind the appropriate value 
      ' to each control.
      Dim firstNameLabel As New Label()
      firstNameLabel.ID = "FirstNameLabel"
      AddHandler firstNameLabel.DataBinding, AddressOf FirstNameLabel_DataBinding

      Dim nameLineBreak As New LiteralControl("<br/>")
      Dim buttonLineBreak As New LiteralControl("<br/>")

      Dim lastNameLabel As New Label()
      lastNameLabel.ID = "LastNameLabel"
      AddHandler lastNameLabel.DataBinding, AddressOf LastNameLabel_DataBinding

      Dim newButton As New Button()
      newButton.ID = "NewButton"
      newButton.CommandName = "New"
      newButton.Text = "New"

      ' Add the controls to the Controls collection of the 
      ' container control.
      container.Controls.Add(firstNameLabel)
      container.Controls.Add(nameLineBreak)
      container.Controls.Add(lastNameLabel)
      container.Controls.Add(buttonLineBreak)
      container.Controls.Add(newButton)
      
    End Sub

    ' This event handler binds the value of the FirstName field
    ' to the FirstNameLabel Label control displayed in the template.
    Private Sub FirstNameLabel_DataBinding(ByVal sender As Object, ByVal e As EventArgs)

      ' Use the sender parameter to retrieve the Label control
      ' being bound to data.
      Dim firstNameLabelControl As Label = CType(sender, Label)

      ' Retrieve the value to bind to the Label control. First,
      ' use the NamingContainer property to retrieve the parent 
      ' control of the Label control. In this example, the parent 
      ' control is the FormView control.
      Dim formViewContainer As FormView = CType(firstNameLabelControl.NamingContainer, FormView)
      
      ' Get the data item bound to the FormView control.
      Dim rowView As DataRowView = CType(formViewContainer.DataItem, DataRowView)

      ' Use the data item to retrieve the value of the FirstName field.
      ' Set the Text property of the Label control to this value.        
      firstNameLabelControl.Text = rowView("FirstName").ToString()
  
    End Sub

    ' This event handler binds the value of the LastName field
    ' to the LastNameLabel Label control displayed in the template.
    Private Sub LastNameLabel_DataBinding(ByVal sender As Object, ByVal e As EventArgs)

      ' Use the sender parameter to retrieve the Label control
      ' being bound to data.
      Dim lastNameLabelControl As Label = CType(sender, Label)

      ' Retrieve the value to bind to the Label control. First,
      ' use the NamingContainer property to retrieve the parent 
      ' control of the Label control. In this example, the parent 
      ' control is the FormView control.
      Dim formViewContainer As FormView = CType(lastNameLabelControl.NamingContainer, FormView)

      ' Get the data item bound to the FormView control.
      Dim rowView As DataRowView = CType(formViewContainer.DataItem, DataRowView)

      ' Use the data item to retrieve the value of the LastName field.
      ' Set the Text property of the Label control to this value.         
      lastNameLabelControl.Text = rowView("LastName").ToString()
    
    End Sub

  End Class
  
  ' This template class represents the insert item
  ' template for a FormView control.
  Private NotInheritable Class EmployeeInsertItemTemplate
    Implements ITemplate

    Sub InstantiateIn(ByVal container As Control) Implements ITemplate.InstantiateIn
      
      ' Create the child controls contained in the template.
      ' The insert item template should contain the input 
      ' controls for the user to enter a record.
      Dim firstNameTextBox As New TextBox()
      firstNameTextBox.ID = "FirstNameTextBox"

      Dim nameLineBreak As New LiteralControl("<br/>")
      Dim buttonLineBreak As New LiteralControl("<br/>")

      Dim lastNameTextBox As New TextBox()
      lastNameTextBox.ID = "LastNameTextBox"

      Dim insertButton As New Button()
      insertButton.ID = "InsertButton"
      insertButton.CommandName = "Insert"
      insertButton.Text = "Insert"

      Dim cancelButton As New Button()
      cancelButton.ID = "CancelButton"
      cancelButton.CommandName = "Cancel"
      cancelButton.Text = "Cancel"

      ' Add the controls to the Controls collection of the 
      ' container control.
      container.Controls.Add(firstNameTextBox)
      container.Controls.Add(nameLineBreak)
      container.Controls.Add(lastNameTextBox)
      container.Controls.Add(buttonLineBreak)
      container.Controls.Add(insertButton)
      container.Controls.Add(cancelButton)

    End Sub
    
  End Class

  Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)

    ' Create a new FormView object.
    Dim employeesFormView As New FormView()

    ' Set the FormView object's properties.
    employeesFormView.ID = "EmployeesFormView"
    employeesFormView.DataSourceID = "EmployeeSource"
    employeesFormView.AllowPaging = True
    employeesFormView.HeaderText = "Employee Name"
    
    Dim keyArray() As String = {"EmployeeID"}
    employeesFormView.DataKeyNames = keyArray

    ' Programmatically register the event handlers for the 
    ' FormView control.
    AddHandler employeesFormView.ItemInserted, AddressOf EmployeeFormView_ItemInserted
    AddHandler employeesFormView.ItemInserting, AddressOf EmployeeFormView_ItemInserting

    ' Create the dynamic templates using the custom template classes.
    employeesFormView.ItemTemplate = New EmployeeItemTemplate()
    employeesFormView.InsertItemTemplate = New EmployeeInsertItemTemplate()
    
    ' Add the FormView object to the Controls collection
    ' of the PlaceHolder control.
    FormViewPlaceHolder.Controls.Add(employeesFormView)

  End Sub

  Sub EmployeeFormView_ItemInserting(ByVal sender As Object, ByVal e As FormViewInsertEventArgs)
    
    ' Because the FormView control is dynamically generated, 
    ' the Values collection must be programmatically populated
    ' with the values for the record to insert.

    ' Use the sender argument to retrieve the FormView
    ' control that raised the event.
    Dim employeeFormView As FormView = CType(sender, FormView)
    
    ' Retrieve the data row from the FormView control.
    Dim row As FormViewRow = employeeFormView.Row

    ' Retrieve the TextBox controls that contain the values 
    ' entered by the user for the new record. 
    Dim firstNameTextBox As TextBox = CType(row.FindControl("FirstNameTextBox"), TextBox)
    Dim lastNameTextBox As TextBox = CType(row.FindControl("LastNameTextBox"), TextBox)

    If firstNameTextBox IsNot Nothing And lastNameTextBox IsNot Nothing Then
    
      ' Add the new values to the Values collections.
      e.Values.Add("FirstName", firstNameTextBox.Text)
      e.Values.Add("LastName", lastNameTextBox.Text)
      
    End If

  End Sub

  Sub EmployeeFormView_ItemInserted(ByVal sender As Object, ByVal e As FormViewInsertedEventArgs)
  
    ' Use the Exception property to determine whether an exception
    ' occurred during the insert operation.
    If e.Exception Is Nothing Then
    
      ' Use the AffectedRows property to determine whether the
      ' record was inserted. Sometimes an error might occur that 
      ' does not raise an exception, but prevents the insert
      ' operation from completing.
      If e.AffectedRows = 1 Then
      
        MessageLabel.Text = "Record inserted successfully."
      
      Else
      
        MessageLabel.Text = "An error occurred during the insert operation."
        
        ' Use the KeepInInsertMode property to keep the control in insert  
        ' mode when an error occurs during the insert operation.
        e.KeepInInsertMode = True
      
      End If
    
    Else
    
      ' Insert the code to handle the exception.
      MessageLabel.Text = e.Exception.Message
      
      ' Use the ExceptionHandled property to indicate that the 
      ' exception has already been handled.
      e.ExceptionHandled = True
      e.KeepInInsertMode = True
    
    End If
        
  End Sub

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>FormView Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>FormView Example</h3>
      
      <!-- Use a PlaceHolder control as the container for the -->
      <!-- dynamically generated FormView control.            -->       
      <asp:placeholder id="FormViewPlaceHolder"
        runat="server"/>
      
      <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] From [Employees]"
        insertcommand="Insert Into [Employees] ([LastName], [FirstName]) VALUES (@LastName, @FirstName)"
        connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>" 
        runat="server"/>
            
    </form>
  </body>
</html>

В следующем примере показано, как декларативно добавить FormViewInsertEventHandler делегат ItemInserting к событию FormView элемента управления.The following example demonstrates how to declaratively add a FormViewInsertEventHandler delegate to the ItemInserting event of a FormView control.


<%@ 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>

Комментарии

Элемент управления CommandName вызывает событие, когда нажата кнопка вставки (кнопка со свойством, равным INSERT) в FormView элементе управления, но до вставки записи в элемент управления. ItemInserting FormViewThe 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. Это позволяет предоставить метод обработки событий, выполняющий пользовательскую подпрограммы, например кодирование HTML или проверку значений записи перед вставкой в источник данных, при каждом возникновении этого события.This allows you to provide an event-handling method that performs a custom routine, such as HTML encoding or validating the values of a record before inserting it in the data source, whenever this event occurs.

При создании делегата FormViewInsertEventHandler необходимо указать метод, обрабатывающий событие.When you create a FormViewInsertEventHandler delegate, you identify the method that will handle the event. Чтобы связать событие с обработчиком событий, нужно добавить в событие экземпляр делегата.To associate the event with your event handler, add an instance of the delegate to the event. Обработчик событий вызывается всякий раз, когда происходит событие, если делегат не удален.The event handler is called whenever the event occurs, unless you remove the delegate. Дополнительные сведения о делегатах обработчиков событий см. в разделе обработка и вызов событий.For more information about event-handler delegates, see Handling and Raising Events.

Методы расширения

GetMethodInfo(Delegate)

Получает объект, представляющий метод, представленный указанным делегатом.Gets an object that represents the method represented by the specified delegate.

Применяется к

Дополнительно