DataGridColumn.SortExpression 属性
定义
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
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。