FormViewUpdateEventArgs.Keys プロパティ

定義

更新するレコードの元のキー フィールドの名前と値のペアが格納されているディクショナリを取得します。

public:
 property System::Collections::Specialized::IOrderedDictionary ^ Keys { System::Collections::Specialized::IOrderedDictionary ^ get(); };
public System.Collections.Specialized.IOrderedDictionary Keys { get; }
member this.Keys : System.Collections.Specialized.IOrderedDictionary
Public ReadOnly Property Keys As IOrderedDictionary

プロパティ値

更新するレコードの元のキー フィールドの名前と値のペアのディクショナリが格納されている IOrderedDictionary

次の例では、 プロパティを Keys 使用して、更新するレコードのキー フィールドの値にアクセスする方法を示します。


<%@ 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_ItemUpdating(Object sender, FormViewUpdateEventArgs e)
  {

    // Validate the field values entered by the user. This
    // example determines whether the user left any fields
    // empty. The names of the empty fields are added to
    // an ArrayList object.
     
    // Use the NewValues property to access the new 
    // values entered by the user.
    ArrayList emptyFieldList = ValidateFields((OrderedDictionary)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["EmployeeID"].ToString();

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

      // Display the missing fields.
      foreach (String value in emptyFieldList)
      {
        // Use the OldValues property to 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(OrderedDictionary 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.
    foreach (DictionaryEntry entry in list)
    {
      if (entry.Value.Equals(""))
      {
        // Add the field name to the ArrayList object.
        emptyFieldList.Add(entry.Key.ToString());
      }
    }

    return emptyFieldList;
  }

  void EmployeeFormView_ModeChanged(Object sender, EventArgs e)
  {
      // Clear the error message label.
      MessageLabel.Text = "";
  }

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>FormViewUpdateEventArgs Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>FormViewUpdateEventArgs Example</h3>
                       
      <asp:formview id="EmployeeFormView"
        datasourceid="EmployeeSource"
        allowpaging="true"
        datakeynames="EmployeeID"
        emptydatatext="No employees found."
        onitemupdating="EmployeeFormView_ItemUpdating"
        onmodechanged="EmployeeFormView_ModeChanged"   
        runat="server">
        
        <itemtemplate>
          <table>
            <tr>
              <td rowspan="6">
                <asp:image id="EmployeeImage"
                  imageurl='<%# Eval("PhotoPath") %>'
                  alternatetext='<%# Eval("LastName") %>' 
                  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 style="height:150" valign="top">
              <td>
                <b>Address:</b>
              </td>
              <td>
                <%# Eval("Address") %><br/>
                <%# Eval("City") %> <%# Eval("Region") %>
                <%# Eval("PostalCode") %><br/>
                <%# Eval("Country") %>   
              </td>
            </tr>
            <tr>
              <td colspan="2">
                <asp:linkbutton id="Edit"
                  text="Edit"
                  commandname="Edit"
                  runat="server"/> 
              </td>
            </tr>
          </table>       
        </itemtemplate>
        <edititemtemplate>
          <table>
            <tr>
              <td rowspan="6">
                <asp:image id="EmployeeEditImage"
                  imageurl='<%# Eval("PhotoPath") %>'
                  alternatetext='<%# Eval("LastName") %>' 
                  runat="server"/>
              </td>
              <td colspan="2">
                    
              </td>
            </tr>
            <tr>
              <td>
                <b><asp:Label runat="server" 
                  AssociatedControlID="FirstNameUpdateTextBox" 
                  Text="Name" />:</b>
              </td>
              <td>
                <asp:textbox id="FirstNameUpdateTextBox"
                  text='<%# Bind("FirstName") %>'
                  accesskey="n" tabindex="1" runat="server"/>
                <asp:textbox id="LastNameUpdateTextBox"
                  text='<%# Bind("LastName") %>'
                  accesskey="l" tabindex="2" runat="server"/>
              </td>
            </tr>
            <tr>
              <td>
                <b><asp:Label runat="server" 
                  AssociatedControlID="TitleUpdateTextBox" 
                  Text="Title" />:</b>
              </td>
              <td>
                <asp:textbox id="TitleUpdateTextBox"
                  text='<%# Bind("Title") %>'
                  accesskey="t" tabindex="3" runat="server"/> 
              </td>
            </tr>
            <tr>
                <b><asp:Label runat="server" 
                  AssociatedControlID="HireDateUpdateTextBox" 
                  Text="Hire Date" />:</b>
              <td>
                <asp:textbox id="HireDateUpdateTextBox"
                  text='<%# Bind("HireDate", "{0:d}") %>'
                  accesskey="h" tabindex="4" runat="server" />
              </td>
            </tr>
            <tr style="height:150" valign="top">
              <td>
                <b><asp:Label runat="server" 
                  AssociatedControlID="AddressUpdateTextBox" 
                  Text="Address" />:</b>
              </td>
              <td>
                <asp:textbox id="AddressUpdateTextBox"
                  text='<%# Bind("Address") %>'
                  accesskey="a" tabindex="5" runat="server"/>
                <br/>
                <asp:textbox id="CityUpdateTextBox"
                  text='<%# Bind("City") %>'
                  accesskey="c" tabindex="6" runat="server"/> 
                <asp:textbox id="RegionUpdateTextBox"
                  text='<%# Bind("Region") %>'
                  width="40"
                  accesskey="r" tabindex="7" runat="server"/>
                <asp:textbox id="PostalCodeUpdateTextBox"
                  text='<%# Bind("PostalCode") %>'
                  width="60"
                  accesskey="p" tabindex="8" runat="server"/>
                <br/>
                <asp:textbox id="CountryUpdateTextBox"
                  text='<%# Bind("Country") %>'
                  accesskey="u" tabindex="9" runat="server"/> 
              </td>
            </tr>
            <tr>
              <td colspan="2">
                <asp:linkbutton id="UpdateButton"
                  text="Update" tabindex="10" 
                  commandname="Update"
                  runat="server"/>
                <asp:linkbutton id="CancelButton"
                  text="Cancel" tabindex="11" 
                  commandname="Cancel"
                  runat="server"/> 
              </td>
            </tr>
          </table>       
        </edititemtemplate>
                  
      </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], [Address], [City], [Region], [PostalCode], [Country], [HireDate], [PhotoPath] From [Employees]"
        updatecommand="Update [Employees] Set [LastName]=@LastName, [FirstName]=@FirstName, [Title]=@Title, [Address]=@Address, [City]=@City, [Region]=@Region, [PostalCode]=@PostalCode, [Country]=@Country Where [EmployeeID]=@EmployeeID"
        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_ItemUpdating(ByVal sender As Object, ByVal e As FormViewUpdateEventArgs) Handles EmployeeFormView.ItemUpdating

    ' Validate the field values entered by the user. This
    ' example determines whether the user left any fields
    ' empty. The names of the empty fields are added to
    ' an ArrayList object.
     
    ' Use the NewValues property to access the new 
    ' values entered by the user.
    Dim emptyFieldList As ArrayList = ValidateFields(CType(e.NewValues, OrderedDictionary))

    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("EmployeeID").ToString()

      MessageLabel.Text = "You must enter a value for each field 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 OrderedDictionary) 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.
    Dim entry As DictionaryEntry
    For Each entry In list
    
      If entry.Value.Equals("") Then
      
        ' Add the field name to the ArrayList object.
        emptyFieldList.Add(entry.Key.ToString())
        
      End If
      
    Next

    Return emptyFieldList
      
  End Function

  Sub EmployeeFormView_ModeChanged(ByVal sender As Object, ByVal e As EventArgs) Handles EmployeeFormView.ModeChanged

    ' Clear the error message label.
    MessageLabel.Text = ""
    
  End Sub

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>FormViewUpdateEventArgs Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>FormViewUpdateEventArgs Example</h3>
                       
      <asp:formview id="EmployeeFormView"
        datasourceid="EmployeeSource"
        allowpaging="true"
        datakeynames="EmployeeID"
        emptydatatext="No employees found."
        runat="server">
        
        <itemtemplate>
          <table>
            <tr>
              <td rowspan="6">
                <asp:image id="EmployeeImage"
                  imageurl='<%# Eval("PhotoPath") %>'
                  alternatetext='<%# Eval("LastName") %>' 
                  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 style="height:150" valign="top">
              <td>
                <b>Address:</b>
              </td>
              <td>
                <%# Eval("Address") %><br/>
                <%# Eval("City") %> <%# Eval("Region") %>
                <%# Eval("PostalCode") %><br/>
                <%# Eval("Country") %>   
              </td>
            </tr>
            <tr>
              <td colspan="2">
                <asp:linkbutton id="Edit"
                  text="Edit"
                  commandname="Edit"
                  runat="server"/> 
              </td>
            </tr>
          </table>       
        </itemtemplate>
        <edititemtemplate>
          <table>
            <tr>
              <td rowspan="6">
                <asp:image id="EmployeeEditImage"
                  imageurl='<%# Eval("PhotoPath") %>'
                  alternatetext='<%# Eval("LastName") %>' 
                  runat="server"/>
              </td>
              <td colspan="2">
                    
              </td>
            </tr>
            <tr>
              <td>
                <b><asp:Label runat="server" 
                  AssociatedControlID="FirstNameUpdateTextBox" 
                  Text="Name" />:</b>
              </td>
              <td>
                <asp:textbox id="FirstNameUpdateTextBox"
                  text='<%# Bind("FirstName") %>'
                  accesskey="n" tabindex="1" runat="server"/>
                <asp:textbox id="LastNameUpdateTextBox"
                  text='<%# Bind("LastName") %>'
                  accesskey="l" tabindex="2" runat="server"/>
              </td>
            </tr>
            <tr>
              <td>
                <b><asp:Label runat="server" 
                  AssociatedControlID="TitleUpdateTextBox" 
                  Text="Title" />:</b>
              </td>
              <td>
                <asp:textbox id="TitleUpdateTextBox"
                  text='<%# Bind("Title") %>'
                  accesskey="t" tabindex="3" runat="server"/> 
              </td>
            </tr>
            <tr>
                <b><asp:Label runat="server" 
                  AssociatedControlID="HireDateUpdateTextBox" 
                  Text="Hire Date" />:</b>
              <td>
                <asp:textbox id="HireDateUpdateTextBox"
                  text='<%# Bind("HireDate", "{0:d}") %>'
                  accesskey="h" tabindex="4" runat="server" />
              </td>
            </tr>
            <tr style="height:150" valign="top">
              <td>
                <b><asp:Label runat="server" 
                  AssociatedControlID="AddressUpdateTextBox" 
                  Text="Address" />:</b>
              </td>
              <td>
                <asp:textbox id="AddressUpdateTextBox"
                  text='<%# Bind("Address") %>'
                  accesskey="a" tabindex="5" runat="server"/>
                <br/>
                <asp:textbox id="CityUpdateTextBox"
                  text='<%# Bind("City") %>'
                  accesskey="c" tabindex="6" runat="server"/> 
                <asp:textbox id="RegionUpdateTextBox"
                  text='<%# Bind("Region") %>'
                  width="40"
                  accesskey="r" tabindex="7" runat="server"/>
                <asp:textbox id="PostalCodeUpdateTextBox"
                  text='<%# Bind("PostalCode") %>'
                  width="60"
                  accesskey="p" tabindex="8" runat="server"/>
                <br/>
                <asp:textbox id="CountryUpdateTextBox"
                  text='<%# Bind("Country") %>'
                  accesskey="u" tabindex="9" runat="server"/> 
              </td>
            </tr>
            <tr>
              <td colspan="2">
                <asp:linkbutton id="UpdateButton"
                  text="Update" tabindex="10" 
                  commandname="Update"
                  runat="server"/>
                <asp:linkbutton id="CancelButton"
                  text="Cancel" tabindex="11" 
                  commandname="Cancel"
                  runat="server"/> 
              </td>
            </tr>
          </table>       
        </edititemtemplate>
                  
      </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], [Address], [City], [Region], [PostalCode], [Country], [HireDate], [PhotoPath] From [Employees]"
        updatecommand="Update [Employees] Set [LastName]=@LastName, [FirstName]=@FirstName, [Title]=@Title, [Address]=@Address, [City]=@City, [Region]=@Region, [PostalCode]=@PostalCode, [Country]=@Country Where [EmployeeID]=@EmployeeID"
        connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>" 
        runat="server"/>
            
    </form>
  </body>
</html>

注釈

Keysプロパティには、コントロールの プロパティに一覧表示されているキー フィールドの元の値がFormViewDataKeyNames含まれます。 プロパティを Keys 使用して、更新するレコードのキー フィールドの元の値にアクセスします。 たとえば、これらの値を使用して、更新されたレコードのログを保持できます。

注意

ユーザーがキー フィールドの値を更新できるようにする場合、 Keys プロパティには元のキー フィールド値が含まれます。 更新された値は、 プロパティに NewValues 格納されます。

プロパティは Keys 、 インターフェイスを OrderedDictionary 実装する オブジェクトを System.Collections.Specialized.IOrderedDictionary 返します。 オブジェクトには OrderedDictionarySystem.Collections.DictionaryEntry 更新されたレコードのフィールドを表す オブジェクトが含まれています。 フィールド名にアクセスするには、 オブジェクトの Keys プロパティを OrderedDictionary 使用します。 同様に、 プロパティを使用してフィールド値に Values アクセスできます。

注意

ショートカットとして、オブジェクトの OrderedDictionary インデクサーを使用してフィールド値に直接アクセスすることもできます。 フィールドの順序 (など AccessDataSource) に依存するデータ ソース コントロールは、インデックスによってのみフィールド値にアクセスできます。

適用対象

こちらもご覧ください