DetailsViewUpdateEventArgs 類別

定義

提供 ItemUpdating 事件的資料。Provides data for the ItemUpdating event.

public ref class DetailsViewUpdateEventArgs : System::ComponentModel::CancelEventArgs
public class DetailsViewUpdateEventArgs : System.ComponentModel.CancelEventArgs
type DetailsViewUpdateEventArgs = class
    inherit CancelEventArgs
Public Class DetailsViewUpdateEventArgs
Inherits CancelEventArgs
繼承
DetailsViewUpdateEventArgs

範例

下列程式碼範例示範如何使用 DetailsViewUpdateEventArgs 傳遞給事件之事件處理常式的物件 ItemUpdating ,來驗證使用者所輸入的值。The following code example demonstrates how to use the DetailsViewUpdateEventArgs object passed to the event handler for the ItemUpdating event to validate the values entered by the user.


<%@ 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 CustomerDetailsView_ItemUpdating(Object sender, 
      DetailsViewUpdateEventArgs e)
    {

        // Validate the field values entered by the user. This
        // example determines whether the user left any fields
        // empty. Use the NewValues property to access the new 
        // values entered by the user.
        ArrayList emptyFieldList = 
          ValidateFields((IOrderedDictionary)e.NewValues);

        if (emptyFieldList.Count > 0)
        {

            // The user left some fields empty. 
            // Display an error message.

            // Use the Keys property to retrieve the key field value.
            String keyValue = e.Keys["CustomerID"].ToString();

            MessageLabel.Text = 
              "You must enter a value for all fields of record " +
              keyValue + ".<br/>The following fields are missing:<br/><br/>";

            // Display the missing fields.
            foreach (String value in emptyFieldList)
            {
                // Use the OldValues property access the original
                // value of a field.
                MessageLabel.Text += value + " - Original Value = " +
                  e.OldValues[value].ToString() + "<br />";
            }

            // Cancel the update operation.
            e.Cancel = true;

        }
        else
        {
            // The field values passed validation. Clear the
            // error message label.
            MessageLabel.Text = "";
        }

    }

    ArrayList ValidateFields(IOrderedDictionary list)
    {

        // Create an ArrayList object to store the
        // names of any empty fields.
        ArrayList emptyFieldList = new ArrayList();

        // Iterate though the field values entered by
        // the user and check for an empty field. Empty
        // fields contain a null value.
        foreach (DictionaryEntry entry in list)
        {
            if (entry.Value == null)
            {
                // Add the field name to the ArrayList object.
                emptyFieldList.Add(entry.Key.ToString());
            }
        }

        return emptyFieldList;
    }

    void CustomerDetailsView_ModeChanging(Object sender, 
      DetailsViewModeEventArgs e)
    {
        if (e.CancelingEdit)
        {
            // The user canceled the update operation.
            // Clear the error message label.
            MessageLabel.Text = "";
        }
    }

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >

  <head runat="server">
    <title>DetailsViewUpdateEventArgs Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>DetailsViewUpdateEventArgs Example</h3>
                       
        <asp:detailsview id="CustomerDetailsView"
          datasourceid="DetailsViewSource"
          autogeneraterows="true"
          autogenerateeditbutton="true"  
          allowpaging="true"
          datakeynames="CustomerID" 
          onitemupdating="CustomerDetailsView_ItemUpdating"
          onmodechanging="CustomerDetailsView_ModeChanging" 
          runat="server">
            
          <pagersettings position="Bottom"/> 
                    
        </asp:detailsview>
        
        <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="DetailsViewSource"
          selectcommand="Select [CustomerID], [CompanyName], [Address], 
            [City], [PostalCode], [Country] From [Customers]"
          updatecommand="Update [Customers] Set 
          [CompanyName]=@CompanyName, [Address]=@Address, 
          [City]=@City, [PostalCode]=@PostalCode, 
          [Country]=@Country 
          Where [CustomerID]=@CustomerID"
          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 CustomerDetailsView_ItemUpdating(ByVal sender As Object, _
    ByVal e As DetailsViewUpdateEventArgs)

    ' Validate the field values entered by the user. This
    ' example determines whether the user left any fields
    ' empty. Use the NewValues property to access the new 
    ' values entered by the user.
    Dim emptyFieldList As ArrayList = _
      ValidateFields(CType(e.NewValues, IOrderedDictionary))

    If emptyFieldList.Count > 0 Then

      ' The user left some fields empty. Display an error message.
      
      ' Use the Keys property to retrieve the key field value.
      Dim keyValue As String = e.Keys("CustomerID").ToString()

      MessageLabel.Text = _
        "You must enter a value for all fields of record " & _
        keyValue & ".<br/>The following fields are missing:<br/><br/>"

      ' Display the missing fields.
      Dim value As String
      For Each value In emptyFieldList
      
        ' Use the OldValues property access the original value
        ' of a field.
        MessageLabel.Text &= value & " - Original Value = " & _
          e.OldValues(value).ToString() & "<br />"
        
      Next

      ' Cancel the update operation.
      e.Cancel = True

    Else
    
      ' The field values passed validation. Clear the
      ' error message label.
      MessageLabel.Text = ""
      
    End If

  End Sub

    Function ValidateFields(ByVal list As IOrderedDictionary) _
      As ArrayList
    
        ' Create an ArrayList object to store the
        ' names of any empty fields.
        Dim emptyFieldList As New ArrayList()

        ' Iterate though the field values entered by
        ' the user and check for an empty field. Empty
        ' fields contain a null value.
        Dim entry As DictionaryEntry
    
        For Each entry In list
    
            If entry.Value Is Nothing Then
      
                ' Add the field name to the ArrayList object.
                emptyFieldList.Add(entry.Key.ToString())
        
            End If
        Next

        Return emptyFieldList
  
    End Function

  Sub CustomerDetailsView_ModeChanging(ByVal sender As Object, ByVal e As DetailsViewModeEventArgs)
  
    If e.CancelingEdit Then
      
      ' The user canceled the update operation.
      ' Clear the error message label.
      MessageLabel.Text = ""
    
    End If
    
  End Sub

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >

  <head runat="server">
    <title>DetailsViewUpdateEventArgs Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>DetailsViewUpdateEventArgs Example</h3>
                       
        <asp:detailsview id="CustomerDetailsView"
          datasourceid="DetailsViewSource"
          autogeneraterows="true"
          autogenerateeditbutton="true"  
          allowpaging="true"
          datakeynames="CustomerID" 
          onitemupdating="CustomerDetailsView_ItemUpdating"
          onmodechanging="CustomerDetailsView_ModeChanging" 
          runat="server">
            
          <pagersettings position="Bottom"/> 
                    
        </asp:detailsview>
        
        <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="DetailsViewSource"
          selectcommand="Select [CustomerID], [CompanyName], [Address], 
          [City], [PostalCode], [Country] From [Customers]"
          updatecommand="Update [Customers] Set 
          [CompanyName]=@CompanyName, [Address]=@Address, 
          [City]=@City, [PostalCode]=@PostalCode, 
          [Country]=@Country 
          Where [CustomerID]=@CustomerID"
          connectionstring=
          "<%$ ConnectionStrings:NorthWindConnectionString%>" 
          runat="server"/>
            
      </form>
  </body>
</html>

備註

DetailsView ItemUpdating 當按一下 [更新] (按鈕時,控制項會引發事件,而此按鈕的 CommandName 屬性會設定為 [更新],但在 DetailsView 控制項更新記錄之前 ) 。The DetailsView control raises the ItemUpdating event when an Update button (a button with its CommandName property set to "Update") within the control is clicked, but before the DetailsView control updates the record. 這可讓您提供執行自訂常式的事件處理常式,例如在資料來源中更新記錄的值,然後在每次發生此事件時進行 HTML 編碼。This allows you to provide an event handler that performs a custom routine, such as HTML-encoding the values of a record before updating it in the data source, whenever this event occurs.

DetailsViewUpdateEventArgs物件會傳遞至事件處理常式,可讓您判斷傳送至控制項的選擇性命令引數值, DetailsView 並指出是否應該取消更新作業。A DetailsViewUpdateEventArgs object is passed to the event handler, which allows you to determine the value of an optional command argument sent to the DetailsView control and to indicate whether the update operation should be canceled. 若要判斷命令引數的值,請使用 CommandArgument 屬性。To determine the value of the command argument, use the CommandArgument property. 若要取消更新作業,請將 Cancel 屬性設定為 trueTo cancel the update operation, set the Cancel property to true. 您也可以使用和屬性,來讀取或修改使用者輸入的新值 Keys NewValuesYou can also read or modify the new values entered by the user by using the Keys and NewValues properties. Keys屬性包含索引鍵欄位,而 NewValues 屬性包含非索引鍵欄位。The Keys property contains the key fields, while the NewValues property contains the non-key fields. 如果您需要存取原始的非索引鍵域值,請使用 OldValues 屬性。If you need to access the original non-key field values, use the OldValues property.

如需如何處理事件的詳細資訊,請參閱 處理和引發事件For more information about how to handle events, see Handling and Raising Events.

如需 DetailsViewUpdateEventArgs 類別之執行個體的初始屬性值清單,請參閱 DetailsViewUpdateEventArgs 建構函式。For a list of initial property values for an instance of the DetailsViewUpdateEventArgs class, see the DetailsViewUpdateEventArgs constructor.

建構函式

DetailsViewUpdateEventArgs(Object)

初始化 DetailsViewUpdateEventArgs 類別的新執行個體。Initializes a new instance of the DetailsViewUpdateEventArgs class.

屬性

Cancel

取得或設定值,這個值表示是否應該取消事件。Gets or sets a value indicating whether the event should be canceled.

(繼承來源 CancelEventArgs)
CommandArgument

取得傳遞至 DetailsView 控制項的更新作業命令引數。Gets the command argument for the update operation passed to the DetailsView control.

Keys

取得字典,其中包含要更新之資料錄的索引鍵欄位名稱/值組。Gets a dictionary that contains the key field name/value pairs for the record to update.

NewValues

取得字典,其包含所要更新之資料錄的新欄位名稱/值組。Gets a dictionary that contains the new field name/value pairs for the record to update.

OldValues

取得字典,其中包含要更新之資料錄的原始欄位名稱/值組。Gets a dictionary that contains the original field name/value pairs for the record to update.

方法

Equals(Object)

判斷指定的物件是否等於目前的物件。Determines whether the specified object is equal to the current object.

(繼承來源 Object)
GetHashCode()

做為預設雜湊函式。Serves as the default hash function.

(繼承來源 Object)
GetType()

取得目前執行個體的 TypeGets the Type of the current instance.

(繼承來源 Object)
MemberwiseClone()

建立目前 Object 的淺層複製。Creates a shallow copy of the current Object.

(繼承來源 Object)
ToString()

傳回代表目前物件的字串。Returns a string that represents the current object.

(繼承來源 Object)

適用於

另請參閱