DataGridColumn.SortExpression 属性

参考

定义

命名空间:: System.Web.UI.WebControls

程序集:: System.Web.dll

重要

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获取或设置选择进行排序的列时传递到 OnSortCommand(DataGridSortCommandEventArgs) 方法的字段或表达式的名称。

public:
 virtual property System::String ^ SortExpression { System::String ^ get(); void set(System::String ^ value); };

public virtual string SortExpression { get; set; }

member this.SortExpression : string with get, set

Public Overridable Property SortExpression As String

属性值

String

选定某列进行排序时传递给 OnSortCommand(DataGridSortCommandEventArgs) 的字段的名称。默认值是 Empty。

示例

下面的代码示例演示如何使用 SortExpression 属性指定要用于排序的字段名称。


<%@ Page Language="C#" AutoEventWireup="True" %>
<%@ Import Namespace="System.Data" %>
 
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
   <script runat="server">
 
      ICollection CreateDataSource()
      {
      
         // Create a Random object to mix up the order of items in the 
         // sample data.
         Random Rand_Num = new Random();

         // Create sample data for the DataGrid control.
         DataTable dt = new DataTable();
         DataRow dr;
 
         // Define the columns of the table.
         dt.Columns.Add(new DataColumn("IntegerValue", typeof(Int32)));
         dt.Columns.Add(new DataColumn("StringValue", typeof(String)));
         dt.Columns.Add(new DataColumn("CurrencyValue", typeof(Double)));
 
         // Populate the table with sample values.
         for (int i=0; i<=8; i++) 
         {

            dr = dt.NewRow();
 
            dr[0] = i;
            dr[1] = "Item " + Rand_Num.Next(1, 15).ToString();
            dr[2] = 1.23 * Rand_Num.Next(1, 15);
 
            dt.Rows.Add(dr);
         
         }

         // To persist the data source between posts to the server,
         // store it in session state.  
         Session["Source"] = dt;
 
         DataView dv = new DataView(dt);

         return dv;
      
      }
 
      void Page_Load(Object sender, EventArgs e)
      { 
 
         // Load sample data only once, when the page is first loaded.
         if (!IsPostBack)
         { 
         
            ItemsGrid.DataSource = CreateDataSource();
            ItemsGrid.DataBind();
         
         }

      }

      void Sort_Grid(Object sender, DataGridSortCommandEventArgs e)
      { 

         // Retrieve the data source from session state.
         DataTable dt = (DataTable)Session["Source"];

         // Create a DataView from the DataTable.
         DataView dv = new DataView(dt);

         // The DataView provides an easy way to sort. Simply set the
         // Sort property with the name of the field to sort by.
         dv.Sort = e.SortExpression;

         // Re-bind the data source and specify that it should be sorted
         // by the field specified in the SortExpression property.
         ItemsGrid.DataSource = dv;
         ItemsGrid.DataBind();

      }

   </script>
 
<head runat="server">
    <title>DataGrid SortExpression Example</title>
</head>
<body>
 
   <form id="form1" runat="server">
 
      <h3>DataGrid SortExpression Example</h3>
 
      <b>Product List</b>
 
      <asp:DataGrid id="ItemsGrid"
           BorderColor="black"
           BorderWidth="1"
           CellPadding="3"
           OnSortCommand="Sort_Grid"
           AutoGenerateColumns="False"
           AllowSorting="True"
           runat="server">

         <HeaderStyle BackColor="#00aaaa">
         </HeaderStyle>

         <Columns>

            <asp:BoundColumn DataField="IntegerValue" 
                 SortExpression="IntegerValue"
                 HeaderText="Item"/>

            <asp:BoundColumn DataField="StringValue"
                 SortExpression="StringValue" 
                 HeaderText="Description"/>

            <asp:BoundColumn DataField="CurrencyValue" 
                 HeaderText="Price"
                 SortExpression="CurrencyValue"
                 DataFormatString="{0:c}">

               <ItemStyle HorizontalAlign="Right">
               </ItemStyle>

            </asp:BoundColumn>

         </Columns> 
 
      </asp:DataGrid>
 
   </form>
 
</body>
</html>


<%@ Page Language="VB" AutoEventWireup="True" %>
<%@ Import Namespace="System.Data" %>
 
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
   <script runat="server">
 
      Function CreateDataSource() As ICollection 
      
         ' Create a Random object to mix up the order of items in the
         ' sample data.
         Dim Rand_Num As Random = New Random()

         ' Create sample data for the DataGrid control.
         Dim dt As DataTable = New DataTable()
         Dim dr As DataRow
 
         ' Define the columns of the table.
         dt.Columns.Add(new DataColumn("IntegerValue", GetType(Int32)))
         dt.Columns.Add(new DataColumn("StringValue", GetType(String)))
         dt.Columns.Add(new DataColumn("CurrencyValue", GetType(Double)))
 
         ' Populate the table with sample values.
         Dim i As Integer

         For i = 0 To 8 
        
            dr = dt.NewRow()
 
            dr(0) = i
            dr(1) = "Item " & Rand_Num.Next(1, 15).ToString()
            dr(2) = 1.23 * Rand_Num.Next(1, 15)
 
            dt.Rows.Add(dr)
         
         Next i

         ' To persist the data source between posts to the server,
         ' store it in session state.  
         Session("Source") = dt
 
         Dim dv As DataView = New DataView(dt)

         Return dv
      
      End Function
 
      Sub Page_Load(sender As Object, e As EventArgs) 
 
         ' Load sample data only once, when the page is first loaded.
         If Not IsPostBack Then 
         
            ItemsGrid.DataSource = CreateDataSource()
            ItemsGrid.DataBind()
         
         End If

      End Sub

      Sub Sort_Grid(sender As Object, e As DataGridSortCommandEventArgs) 

         ' Retrieve the data source from session state.
         Dim dt As DataTable = CType(Session("Source"), DataTable)

         ' Create a DataView from the DataTable.
         Dim dv As DataView = New DataView(dt)

         ' The DataView provides an easy way to sort. Simply set the
         ' Sort property with the name of the field to sort by.
         dv.Sort = e.SortExpression

         ' Re-bind the data source and specify that it should be sorted
         ' by the field specified in the SortExpression property.
         ItemsGrid.DataSource = dv
         ItemsGrid.DataBind()

      End Sub

   </script>
 
<head runat="server">
    <title>DataGrid SortExpression Example</title>
</head>
<body>
 
   <form id="form1" runat="server">
 
      <h3>DataGrid SortExpression Example</h3>
 
      <b>Product List</b>
 
      <asp:DataGrid id="ItemsGrid"
           BorderColor="black"
           BorderWidth="1"
           CellPadding="3"
           OnSortCommand="Sort_Grid"
           AutoGenerateColumns="False"
           AllowSorting="True"
           runat="server">

         <HeaderStyle BackColor="#00aaaa">
         </HeaderStyle>

         <Columns>

            <asp:BoundColumn DataField="IntegerValue" 
                 SortExpression="IntegerValue"
                 HeaderText="Item"/>

            <asp:BoundColumn DataField="StringValue"
                 SortExpression="StringValue" 
                 HeaderText="Description"/>

            <asp:BoundColumn DataField="CurrencyValue" 
                 HeaderText="Price"
                 SortExpression="CurrencyValue"
                 DataFormatString="{0:c}">

               <ItemStyle HorizontalAlign="Right">
               </ItemStyle>

            </asp:BoundColumn>

         </Columns> 
 
      </asp:DataGrid>
 
   </form>
 
</body>
</html>

注解

选择列进行排序时， SortExpression 使用属性可以指定或确定要传递给 OnSortCommand 方法的字段的名称。

注意

此属性不将列绑定到数据源中的字段。若要将列绑定到字段，请参阅特定列类型的文档。

启用排序后， LinkButton 控件将呈现在设置了属性的每个列 SortExpression 的标题部分中。

注意

当属性 AutoGenerateColumns 设置为 true时， SortExpression 将自动设置控件中 DataGrid 支持数据绑定的每个列的属性，并将字段名称绑定到列。如果属性 AutoGenerateColumns 设置为 false，则需要手动设置属性， SortExpression 并将字段名称绑定到要为其启用排序的每个列的列。

这些 LinkButton 控件允许按所选列对控件进行排序 DataGrid 。 LinkButton单击列的控件时，将引发事件SortCommand。所选列的 SortExpression 属性值作为 OnSortCommand 对象的一部分 DataGridSortCommandEventArgs 传递给事件处理程序。

适用于

DataGridColumn.SortExpression 属性

定义

属性值

示例

注解

适用于

另请参阅

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