FormViewUpdatedEventArgs.Keys 属性

定义

获取一个字典,该字典包含已更新记录的原始键字段的名称/值对。Gets a dictionary that contains the original key field name/value pairs for the updated record.

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

属性值

IOrderedDictionary

IOrderedDictionary 包含一个字典,该字典由已更新记录的原始键字段的名称/值对组成。An IOrderedDictionary that contains a dictionary of the original key field name/value pairs for the updated record.

示例

下面的示例演示如何使用 Keys 属性访问已更新记录的键字段的值。The following example demonstrates how to use the Keys property to access the values of the key field for an updated record.


<%@ 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_ItemUpdated(Object sender, FormViewUpdatedEventArgs e)
  {
    // Use the Exception property to determine whether an exception
    // occurred during the update operation.
    if (e.Exception == null)
    {
      // Sometimes an error might occur that does not raise an 
      // exception, but prevents the update operation from 
      // completing. Use the AffectedRows property to determine 
      // whether the record was actually updated. 
      if (e.AffectedRows == 1)
      {
        // Use the Keys property to get the value of the key field.
        String keyFieldValue = e.Keys["EmployeeID"].ToString();

        // Display a confirmation message.
        MessageLabel.Text = "Record " + keyFieldValue +
          " updated successfully. ";

        // Display the new and original values.
        DisplayValues((OrderedDictionary)e.NewValues, (OrderedDictionary)e.OldValues);
      }
      else
      {
        // Display an error message.
        MessageLabel.Text = "An error occurred during the update operation.";

        // When an error occurs, keep the FormView
        // control in edit mode.
        e.KeepInEditMode = 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.KeepInEditMode = true;
    }
  }

  void DisplayValues(OrderedDictionary newValues, OrderedDictionary oldValues)
  {

    MessageLabel.Text += "<br/></br>";

    // Iterate through the new and old values. Display the
    // values on the page.
    for (int i = 0; i < oldValues.Count; i++)
    {
      MessageLabel.Text += "Old Value=" + oldValues[i].ToString() +
        ", New Value=" + newValues[i].ToString() + "<br/>";
    }

    MessageLabel.Text += "</br>";

  }

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>FormViewUpdatedEventArgs Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>FormViewUpdatedEventArgs Example</h3>
                       
      <asp:formview id="EmployeeFormView"
        datasourceid="EmployeeSource"
        allowpaging="true"
        datakeynames="EmployeeID"
        emptydatatext="No employees found."
        onitemupdated="EmployeeFormView_ItemUpdated"   
        runat="server">
        
        <itemtemplate>
          <table>
            <tr>
              <td rowspan="6">
                <asp:image id="EmployeeImage"
                  imageurl='<%# Eval("PhotoPath") %>'
                  alternatetext='<%# Eval("LastName") %>' 
                  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>
                <b>Hire Date:</b>                 
              </td>
              <td>
                <%# Eval("HireDate","{0:d}") %>
              </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">
                  &nbsp; 
              </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_ItemUpdated(ByVal sender As Object, ByVal e As FormViewUpdatedEventArgs) Handles EmployeeFormView.ItemUpdated

    ' Use the Exception property to determine whether an exception
    ' occurred during the update operation.
    If e.Exception Is Nothing Then
    
      ' Sometimes an error might occur that does not raise an 
      ' exception, but prevents the update operation from 
      ' completing. Use the AffectedRows property to determine 
      ' whether the record was actually updated. 
      If e.AffectedRows = 1 Then
      
        ' Use the Keys property to get the value of the key field.
        Dim keyFieldValue As String = e.Keys("EmployeeID").ToString()

        ' Display a confirmation message.
        MessageLabel.Text = "Record " & keyFieldValue & _
          " updated successfully. "

        ' Display the new and original values.
        DisplayValues(CType(e.NewValues, OrderedDictionary), CType(e.OldValues, OrderedDictionary))
      
      Else
      
        ' Display an error message.
        MessageLabel.Text = "An error occurred during the update operation."

        ' When an error occurs, keep the FormView
        ' control in edit mode.
        e.KeepInEditMode = 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.KeepInEditMode = True
    
    End If
    
  End Sub

  Sub DisplayValues(ByVal newValues As OrderedDictionary, ByVal oldValues As OrderedDictionary)

    MessageLabel.Text &= "<br/></br>"

    ' Iterate through the new and old values. Display the
    ' values on the page.
    Dim i As Integer
    For i = 0 To oldValues.Count - 1
    
      MessageLabel.Text &= "Old Value=" & oldValues(i).ToString() & _
        ", New Value=" & newValues(i).ToString() & "<br/>"
    Next

    MessageLabel.Text &= "</br>"

  End Sub

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>FormViewUpdatedEventArgs Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>FormViewUpdatedEventArgs 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">
                  &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>
                <b>Hire Date:</b>                 
              </td>
              <td>
                <%# Eval("HireDate","{0:d}") %>
              </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">
                  &nbsp; 
              </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>

注解

Keys属性包含控件的属性中列出的键字段的原始值 DataKeyNames FormViewThe Keys property contains the original values of the key fields listed in the DataKeyNames property of a FormView control. 使用 Keys 属性可访问已更新记录的键字段的值。Use the Keys property to access the values of the key field for an updated record. 例如,你可以使用这些值来记录已更新的记录。For example, you can use these values to keep a log of updated records.

备注

如果允许用户更新键字段的值,则 Keys 属性将包含原始键字段值。If you allow the user to update the values of the key fields, the Keys property contains the original key field values. 更新的值存储在属性中 NewValuesThe updated values are stored in the NewValues property.

Keys属性返回 OrderedDictionary 实现接口的对象 System.Collections.Specialized.IOrderedDictionaryThe Keys property returns an OrderedDictionary object that implements the System.Collections.Specialized.IOrderedDictionary interface. OrderedDictionary对象包含 System.Collections.DictionaryEntry 表示已更新记录的字段的对象。The OrderedDictionary object contains System.Collections.DictionaryEntry objects that represent the fields of the updated record. 若要访问字段名称,请使用 Keys 对象的属性 OrderedDictionaryTo access the field names, use the Keys property of the OrderedDictionary object. 同样,可以使用属性访问字段值 ValuesSimilarly, you can access the field values by using the Values property.

备注

作为一种快捷方式,还可以使用对象的索引器 OrderedDictionary 直接访问字段值。As a shortcut, you can also use the indexer of the OrderedDictionary object to access the field values directly. 依赖于字段顺序的数据源控件 (如 AccessDataSource) 只能通过索引访问字段值。Data source controls that rely on the field order (such as AccessDataSource) can access field values only by index.

适用于

另请参阅