ObjectDataSourceView.FilterParameters 屬性
定義
重要
部分資訊涉及發行前產品,在發行之前可能會有大幅修改。 Microsoft 對此處提供的資訊,不做任何明確或隱含的瑕疵擔保。
取得與 FilterExpression 字串中任何參數替代符號相關聯的參數集合。
public:
property System::Web::UI::WebControls::ParameterCollection ^ FilterParameters { System::Web::UI::WebControls::ParameterCollection ^ get(); };
public System.Web.UI.WebControls.ParameterCollection FilterParameters { get; }
member this.FilterParameters : System.Web.UI.WebControls.ParameterCollection
Public ReadOnly Property FilterParameters As ParameterCollection
屬性值
ParameterCollection,其中所包含的一組參數,與在 FilterExpression 屬性中找到的任何參數預留位置相關聯。
例外狀況
設定了 FilterExpression 屬性,且 Select(DataSourceSelectArguments) 方法沒有傳回 DataSet。
範例
本節包含兩個程式碼範例。 第一個程式碼範例示範如何使用 控制項顯示篩選的資料,以從仲介層商務物件擷取資料 ObjectDataSource ,以及 GridView 顯示結果的控制項。 第二個程式碼範例提供第一個程式碼範例中使用的仲介層商務物件範例。
下列程式碼範例示範如何使用 控制項顯示篩選的資料,以從仲介層商務物件擷取資料 ObjectDataSource ,以及 GridView 顯示結果的控制項。 ObjectDataSource只有當擷取資料的方法擷取資料做為 DataSet 物件時,控制項才能篩選資料。 基於這個理由, SelectMethod 屬性會識別將資料擷取為 DataSet 的商務物件方法。
程式碼範例包含 TextBox 、 GridView 控制項、 ObjectDataSource 控制項和 [提交] 按鈕。 根據預設,會 TextBox 填入其中一個 Northwind Traders 員工的名稱。 會顯示 GridView 中 TextBox 名稱所識別之員工的相關資訊。 若要擷取另一位員工的資料,請在 中 TextBox 輸入員工的完整名稱,然後按一下 [ 提交 ] 按鈕。
屬性 FilterExpression 會指定運算式,用來篩選 屬性所指定方法所 SelectMethod 擷取的資料。 它會使用評估為集合中所含參數的參數 FilterParameters 預留位置。 在此範例中,參數預留位置會以單引號系結,因為參數的類型是可能包含空格的字串類型。 如果參數的類型是數值或日期類型,則不需要周框引號。 FilterParameters集合包含一個參數, FormParameter 也就是系結至 控制項的 TextBox 。
<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.CS" Assembly="Samples.AspNet.CS" %>
<%@ 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">
protected void ObjectDataSource1_Filtering(object sender, ObjectDataSourceFilteringEventArgs e)
{
if (Textbox1.Text == "")
{
e.ParameterValues.Clear();
e.ParameterValues.Add("FullName", "Nancy Davolio");
}
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
<title>ObjectDataSource - C# Example</title>
</head>
<body>
<form id="Form1" method="post" runat="server">
<p>Show all users with the following name.</p>
<asp:textbox id="Textbox1" runat="server" text="Nancy Davolio" />
<asp:gridview
id="GridView1"
runat="server"
datasourceid="ObjectDataSource1"
autogeneratecolumns="False">
<columns>
<asp:boundfield headertext="ID" datafield="EmpID" />
<asp:boundfield headertext="Name" datafield="FullName" />
<asp:boundfield headertext="Street Address" datafield="Address" />
</columns>
</asp:gridview>
<!-- Security Note: The ObjectDataSource uses a FormParameter,
Security Note: which does not perform validation of input from the client. -->
<asp:objectdatasource
id="ObjectDataSource1"
runat="server"
selectmethod="GetAllEmployeesAsDataSet"
typename="Samples.AspNet.CS.EmployeeLogic"
filterexpression="FullName='{0}'" OnFiltering="ObjectDataSource1_Filtering">
<filterparameters>
<asp:formparameter name="FullName" formfield="Textbox1" defaultvalue="Nancy Davolio" />
</filterparameters>
</asp:objectdatasource>
<p><asp:button id="Button1" runat="server" text="Search" /></p>
</form>
</body>
</html>
<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.VB" Assembly="Samples.AspNet.VB" %>
<%@ 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">
Protected Sub ObjectDataSource1_Filtering(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.ObjectDataSourceFilteringEventArgs)
If Textbox1.Text = "" Then
e.ParameterValues.Clear()
e.ParameterValues.Add("FullName", "Nancy Davolio")
End If
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
<title>ObjectDataSource - VB Example</title>
</head>
<body>
<form id="Form1" method="post" runat="server">
<p>Show all users with the following name.</p>
<asp:textbox id="Textbox1" runat="server" text="Nancy Davolio" />
<asp:gridview
id="GridView1"
runat="server"
datasourceid="ObjectDataSource1"
autogeneratecolumns="False">
<columns>
<asp:boundfield headertext="ID" datafield="EmpID" />
<asp:boundfield headertext="Name" datafield="FullName" />
<asp:boundfield headertext="Street Address" datafield="Address" />
</columns>
</asp:gridview>
<!-- Security Note: The ObjectDataSource uses a FormParameter,
Security Note: which does not perform validation of input from the client. -->
<asp:objectdatasource
id="ObjectDataSource1"
runat="server"
selectmethod="GetAllEmployeesAsDataSet"
typename="Samples.AspNet.VB.EmployeeLogic"
filterexpression="FullName='{0}'" OnFiltering="ObjectDataSource1_Filtering">
<filterparameters>
<asp:formparameter name="FullName" formfield="Textbox1" defaultvalue="Nancy Davolio" />
</filterparameters>
</asp:objectdatasource>
<p><asp:button id="Button1" runat="server" text="Search" /></p>
</form>
</body>
</html>
下列程式碼範例提供上述程式碼範例所使用的仲介層商務物件範例。 程式碼範例包含兩個基本類別:
類別
EmployeeLogic
,這是封裝商務邏輯的類別。類別
NorthwindEmployee
,這是一個模型類別,其中包含從資料層載入和保存資料所需的基本功能。
為了簡單起見,類別 EmployeeLogic
會建立靜態資料集,而不是從資料層擷取資料。 此範例也很有説明,因為此範例依賴您提供 Northwind Traders 員工的完整名稱來示範篩選。
如需完整的工作範例,您必須編譯並使用這些類別搭配提供的Web Form頁程式碼範例。
namespace Samples.AspNet.CS {
using System;
using System.Collections;
using System.Data;
using System.Web.UI.WebControls;
//
// EmployeeLogic is a stateless business object that encapsulates
// the operations you can perform on a NorthwindEmployee object.
//
public class EmployeeLogic {
// Returns a collection of NorthwindEmployee objects.
public static ICollection GetAllEmployees () {
ArrayList data = new ArrayList();
data.Add(new NorthwindEmployee(1,"Nancy","Davolio","507 - 20th Ave. E. Apt. 2A"));
data.Add(new NorthwindEmployee(2,"Andrew","Fuller","908 W. Capital Way"));
data.Add(new NorthwindEmployee(3,"Janet","Leverling","722 Moss Bay Blvd."));
data.Add(new NorthwindEmployee(4,"Margaret","Peacock","4110 Old Redmond Rd."));
data.Add(new NorthwindEmployee(5,"Steven","Buchanan","14 Garrett Hill"));
data.Add(new NorthwindEmployee(6,"Michael","Suyama","Coventry House Miner Rd."));
data.Add(new NorthwindEmployee(7,"Robert","King","Edgeham Hollow Winchester Way"));
return data;
}
public static NorthwindEmployee GetEmployee(object anID) {
ArrayList data = GetAllEmployees() as ArrayList;
int empID = Int32.Parse(anID.ToString());
return data[empID] as NorthwindEmployee;
}
//
// To support basic filtering, the employees cannot
// be returned as an array of objects, rather as a
// DataSet of the raw data values.
public static DataSet GetAllEmployeesAsDataSet () {
ICollection employees = GetAllEmployees();
DataSet ds = new DataSet("Table");
// Create the schema of the DataTable.
DataTable dt = new DataTable();
DataColumn dc;
dc = new DataColumn("EmpID", typeof(int)); dt.Columns.Add(dc);
dc = new DataColumn("FullName",typeof(string)); dt.Columns.Add(dc);
dc = new DataColumn("Address", typeof(string)); dt.Columns.Add(dc);
// Add rows to the DataTable.
DataRow row;
foreach (NorthwindEmployee ne in employees) {
row = dt.NewRow();
row["EmpID"] = ne.EmpID;
row["FullName"] = ne.FullName;
row["Address"] = ne.Address;
dt.Rows.Add(row);
}
// Add the complete DataTable to the DataSet.
ds.Tables.Add(dt);
return ds;
}
}
public class NorthwindEmployee {
public NorthwindEmployee (int anID,
string aFirstName,
string aLastName,
string anAddress) {
ID = anID;
firstName = aFirstName;
lastName = aLastName;
address = anAddress;
}
private object ID;
public string EmpID {
get { return ID.ToString(); }
}
private string lastName;
public string LastName {
get { return lastName; }
set { lastName = value; }
}
private string firstName;
public string FirstName {
get { return firstName; }
set { firstName = value; }
}
public string FullName {
get { return FirstName + " " + LastName; }
}
private string address;
public string Address {
get { return address; }
set { address = value; }
}
}
}
Imports System.Collections
Imports System.Data
Imports System.Web.UI.WebControls
Namespace Samples.AspNet.VB
'
' EmployeeLogic is a stateless business object that encapsulates
' the operations you can perform on a NorthwindEmployee object.
'
Public Class EmployeeLogic
' Returns a collection of NorthwindEmployee objects.
Public Shared Function GetAllEmployees() As ICollection
Dim data As New ArrayList()
data.Add(New NorthwindEmployee(1, "Nancy", "Davolio", "507 - 20th Ave. E. Apt. 2A"))
data.Add(New NorthwindEmployee(2, "Andrew", "Fuller", "908 W. Capital Way"))
data.Add(New NorthwindEmployee(3, "Janet", "Leverling", "722 Moss Bay Blvd."))
data.Add(New NorthwindEmployee(4, "Margaret", "Peacock", "4110 Old Redmond Rd."))
data.Add(New NorthwindEmployee(5, "Steven", "Buchanan", "14 Garrett Hill"))
data.Add(New NorthwindEmployee(6, "Michael", "Suyama", "Coventry House Miner Rd."))
data.Add(New NorthwindEmployee(7, "Robert", "King", "Edgeham Hollow Winchester Way"))
Return data
End Function 'GetAllEmployees
Public Shared Function GetEmployee(anID As Object) As NorthwindEmployee
Dim data As ArrayList = CType(GetAllEmployees(), ArrayList)
Dim empID As Integer = Int32.Parse(anID.ToString())
Return CType(data(empID),NorthwindEmployee)
End Function 'GetEmployee
' To support basic filtering, the employees cannot
' be returned as an array of objects, rather as a
' DataSet of the raw data values.
Public Shared Function GetAllEmployeesAsDataSet() As DataSet
Dim employees As ICollection = GetAllEmployees()
Dim ds As New DataSet("Table")
' Create the schema of the DataTable.
Dim dt As New DataTable()
Dim dc As DataColumn
dc = New DataColumn("EmpID", GetType(Integer))
dt.Columns.Add(dc)
dc = New DataColumn("FullName", GetType(String))
dt.Columns.Add(dc)
dc = New DataColumn("Address", GetType(String))
dt.Columns.Add(dc)
' Add rows to the DataTable.
Dim row As DataRow
Dim ne As NorthwindEmployee
For Each ne In employees
row = dt.NewRow()
row("EmpID") = ne.EmpID
row("FullName") = ne.FullName
row("Address") = ne.Address
dt.Rows.Add(row)
Next
' Add the complete DataTable to the DataSet.
ds.Tables.Add(dt)
Return ds
End Function 'GetAllEmployeesAsDataSet
End Class
Public Class NorthwindEmployee
Public Sub New(anID As Integer, aFirstName As String, aLastName As String, anAddress As String)
ID = anID
Me.aFirstName = aFirstName
Me.aLastName = aLastName
Me.aAddress = anAddress
End Sub
Private ID As Object
Public ReadOnly Property EmpID() As String
Get
Return ID.ToString()
End Get
End Property
Private aLastName As String
Public Property LastName() As String
Get
Return aLastName
End Get
Set
aLastName = value
End Set
End Property
Private aFirstName As String
Public Property FirstName() As String
Get
Return aFirstName
End Get
Set
aFirstName = value
End Set
End Property
Public ReadOnly Property FullName() As String
Get
Return FirstName & " " & LastName
End Get
End Property
Private aAddress As String
Public Property Address() As String
Get
Return aAddress
End Get
Set
aAddress = value
End Set
End Property
End Class
End Namespace
備註
只有當方法傳 DataSet 回 、 DataTable 或 DataView 物件時 Select ,控制項 ObjectDataSource 才支援篩選資料。
集合中的 FilterParameters 參數會與 屬性中指定的 FilterExpression 任何參數相關聯。 呼叫 屬性所指定的 SelectMethod 方法時,屬性中指定的 FilterExpression 參數預留位置會比對集合中的 FilterParameters 參數物件。