DataKey.Item[] 属性

参考

定义

命名空间:: System.Web.UI.WebControls

程序集:: System.Web.dll

重要

一些信息与预发行产品相关，相应产品在发行之前可能会进行重大修改。对于此处提供的信息，Microsoft 不作任何明示或暗示的担保。

从 DataKey 对象中获取键字段的值。

重载

Item[Int32]	从 DataKey 对象中的指定索引位置获取键字段的值。
Item[String]	从 DataKey 对象中获取具有指定字段名的键字段的值。

Item[Int32]

从 DataKey 对象中的指定索引位置获取键字段的值。

public:
 virtual property System::Object ^ default[int] { System::Object ^ get(int index); };

public virtual object this[int index] { get; }

member this.Item(int) : obj

Default Public Overridable ReadOnly Property Item(index As Integer) As Object

参数

index: Int32

检索键字段值的从零开始的索引。

属性值

Object

指定索引位置的键字段值。

示例

下面的代码示例演示如何使用 Item[Int32] 属性从对象中的 DataKey 特定索引检索键字段值。


<%@ 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_DataBound(Object sender, EventArgs e)
  {

    // Get the value of the key field at index 2 in the DataKey object.
    String value = CustomerDetailsView.DataKey[2].ToString();

    // Display the value of the key field.
    MessageLabel.Text = "The value of the PostalCode key field is " + value +
      ".";

  }
  
</script>

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

  <head runat="server">
    <title>DataKey Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>DataKey Example</h3>
                       
        <asp:detailsview id="CustomerDetailsView"
          datasourceid="DetailsViewSource"
          autogeneraterows="true"
          datakeynames="CustomerID, CompanyName, PostalCode"  
          allowpaging="true"
          ondatabound="CustomerDetailsView_DataBound" 
          runat="server">
            
        </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]"
          connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>" 
          runat="server"/>
            
      </form>
  </body>
</html>


<%@ Page language="VB" autoeventwireup="false" %>

<!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_DataBound(ByVal sender As Object, ByVal e As EventArgs) Handles CustomerDetailsView.DataBound

    ' Get the value of the key field at index 2 in the DataKey object.
    Dim value As String = CustomerDetailsView.DataKey(2).ToString()

    ' Display the value of the key field.
    MessageLabel.Text = "The value of the PostalCode key field is " & value & _
      "."

  End Sub
  
</script>

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

  <head runat="server">
    <title>DataKey Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>DataKey Example</h3>
                       
        <asp:detailsview id="CustomerDetailsView"
          datasourceid="DetailsViewSource"
          autogeneraterows="true"
          datakeynames="CustomerID, CompanyName, PostalCode"  
          allowpaging="true"
          runat="server">
            
        </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]"
          connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>" 
          runat="server"/>
            
      </form>
  </body>
</html>

注解

Item[Int32]使用属性检索对象中DataKey指定索引处的键字段的值。

注意

作为替代方法，还可以使用 Item[String] 属性按字段名称检索键字段值。

另请参阅

Values
Value

适用于

Item[String]

从 DataKey 对象中获取具有指定字段名的键字段的值。

public:
 virtual property System::Object ^ default[System::String ^] { System::Object ^ get(System::String ^ name); };

public virtual object this[string name] { get; }

member this.Item(string) : obj

Default Public Overridable ReadOnly Property Item(name As String) As Object

参数

name: String

要检索其键字段值的键字段的名称。

属性值

Object

具有指定字段名的键字段的值。

示例

下面的代码示例演示如何使用 Item[String] 属性从对象中的 DataKey 特定索引检索键字段值。


<%@ 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_DataBound(Object sender, EventArgs e)
  {

    // Get the value of the PostalCode key field.
    String value = CustomerDetailsView.DataKey["PostalCode"].ToString();

    // Display the value of the key field.
    MessageLabel.Text = "The value of the PostalCode key field is " + value +
      ".";

  }
  
</script>

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

  <head runat="server">
    <title>DataKey Example</title>
</head>
<body>
    <form id="Form1" runat="server">
        
      <h3>DataKey Example</h3>
                       
        <asp:detailsview id="CustomerDetailsView"
          datasourceid="DetailsViewSource"
          autogeneraterows="true"
          datakeynames="CustomerID, CompanyName, PostalCode"  
          allowpaging="true"
          ondatabound="CustomerDetailsView_DataBound" 
          runat="server">
            
        </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]"
          connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>" 
          runat="server"/>
            
      </form>
  </body>
</html>


<%@ Page language="VB" autoeventwireup="false" %>

<!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_DataBound(ByVal sender As Object, ByVal e As EventArgs) Handles CustomerDetailsView.DataBound

    ' Get the value of the PostalCode key field.
    Dim value As String = CustomerDetailsView.DataKey("PostalCode").ToString()

    ' Display the value of the key field.
    MessageLabel.Text = "The value of the PostalCode key field is " & value & _
      "."

  End Sub
  
</script>

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

  <head runat="server">
    <title>DataKey Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>DataKey Example</h3>
                       
        <asp:detailsview id="CustomerDetailsView"
          datasourceid="DetailsViewSource"
          autogeneraterows="true"
          datakeynames="CustomerID, CompanyName, PostalCode"  
          allowpaging="true"
          runat="server">
            
        </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]"
          connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>" 
          runat="server"/>
            
      </form>
  </body>
</html>

注解

Item[String]使用属性可从对象中检索指定键字段DataKey的值。

注意

作为替代方法，还可以使用 Item[Int32] 属性按索引检索键字段值。

另请参阅

Values
Value

适用于

通过

DataKey.Item[] 属性

定义

重载

Item[Int32]

参数

属性值

示例

注解

另请参阅

适用于

Item[String]

参数

属性值

示例

注解

另请参阅

适用于

其他资源