ControlParameter.ControlID 屬性
定義
指定 ControlParameter 物件繫結至之控制項的名稱。Specifies the name of the control that the ControlParameter object binds to.
public:
property System::String ^ ControlID { System::String ^ get(); void set(System::String ^ value); };
[System.ComponentModel.TypeConverter(typeof(System.Web.UI.WebControls.ControlIDConverter))]
public string ControlID { get; set; }
[<System.ComponentModel.TypeConverter(typeof(System.Web.UI.WebControls.ControlIDConverter))>]
member this.ControlID : string with get, set
Public Property ControlID As String
屬性值
string
,表示 Web 伺服器控制項的名稱。A string
that represents the name of a Web server control.
- 屬性
範例
下列程式碼範例示範如何使用 ControlParameter 物件,將控制項中顯示的資料系結 ListBox 至宣告式 DropDownList 案例中控制項的選取值。The following code example demonstrates how to use a ControlParameter object to bind data displayed in a ListBox control to the selected value of a DropDownList control in a declarative scenario. ControlParameter物件會加入至 SelectParameters SqlDataSource 表單上的控制項集合中,並對應至屬性中的 " @Title " 預留位置文字 SelectCommand 。The ControlParameter object is added to the SelectParameters collection of the SqlDataSource control on the form, and corresponds to the "@Title" placeholder text in the SelectCommand property.
<!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" >
<head runat="server">
<title>ASP.NET Example</title>
</head>
<body>
<form id="form1" runat="server">
<p><asp:dropdownlist
id="DropDownList1"
runat="server"
autopostback="True">
<asp:listitem selected="True">Sales Representative</asp:listitem>
<asp:listitem>Sales Manager</asp:listitem>
<asp:listitem>Vice President, Sales</asp:listitem>
</asp:dropdownlist></p>
<asp:sqldatasource
id="SqlDataSource1"
runat="server"
connectionstring="<%$ ConnectionStrings:MyNorthwind%>"
selectcommand="SELECT LastName FROM Employees WHERE Title = @Title">
<selectparameters>
<asp:controlparameter name="Title" controlid="DropDownList1" propertyname="SelectedValue"/>
</selectparameters>
</asp:sqldatasource>
<p><asp:listbox
id="ListBox1"
runat="server"
datasourceid="SqlDataSource1"
datatextfield="LastName">
</asp:listbox></p>
</form>
</body>
</html>
<!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" >
<head runat="server">
<title>ASP.NET Example</title>
</head>
<body>
<form id="form1" runat="server">
<p><asp:dropdownlist
id="DropDownList1"
runat="server"
autopostback="True">
<asp:listitem selected="True">Sales Representative</asp:listitem>
<asp:listitem>Sales Manager</asp:listitem>
<asp:listitem>Vice President, Sales</asp:listitem>
</asp:dropdownlist></p>
<asp:sqldatasource
id="SqlDataSource1"
runat="server"
connectionstring="<%$ ConnectionStrings:MyNorthwind%>"
selectcommand="SELECT LastName FROM Employees WHERE Title = @Title">
<selectparameters>
<asp:controlparameter name="Title" controlid="DropDownList1" propertyname="SelectedValue"/>
</selectparameters>
</asp:sqldatasource>
<p><asp:listbox
id="ListBox1"
runat="server"
datasourceid="SqlDataSource1"
datatextfield="LastName">
</asp:listbox></p>
</form>
</body>
</html>
下列程式碼範例示範如何設定 ControlID 和屬性, PropertyName 以識別物件所系結的控制項 ControlParameter 。The following code example demonstrates how to set the ControlID and PropertyName properties to identify the control that a ControlParameter object is bound to. 此範例會將 ListBox 值填入控制項。The example populates a ListBox control with values. SelectedValue控制項的屬性 ListBox 是用來篩選控制項所抓取 SqlDataSource 並由控制項顯示的資料 GridView 。The SelectedValue property of the ListBox control is used to filter data retrieved by a SqlDataSource control and displayed by a GridView control.
<%@ 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">
private void Page_Load(object sender, System.EventArgs e)
{
if (IsPostBack) {
GridView1.DataBind();
}
else {
ListBox1.Items.Add(new ListItem("Nancy Davolio", "1",true));
ListBox1.Items.Add(new ListItem("Janet Leverling", "3",true));
ListBox1.Items.Add(new ListItem("Margaret Peacock","4",true));
ListBox1.Items.Add(new ListItem("Michael Suyama", "6",true));
ListBox1.Items.Add(new ListItem("Robert King", "7",true));
ListBox1.Items.Add(new ListItem("Anne Dodsworth", "9",true));
}
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>ASP.NET Example</title>
</head>
<body>
<form id="Form1" method="post" runat="server">
<p>Show Orders For:</p>
<p>
<asp:ListBox
id="ListBox1"
runat="server"
AutoPostBack="True">
</asp:ListBox></p>
<asp:SqlDataSource
id="OdbcDataSource1"
runat="server"
ProviderName="System.Data.Odbc"
DataSourceMode="DataSet"
SelectCommand="SELECT OrderID, ShipName FROM Orders WHERE EmployeeID = ?;"
ConnectionString="dsn=MyOdbcDSN;">
<SELECTPARAMETERS>
<asp:ControlParameter
PropertyName="SelectedValue"
ControlID="ListBox1"
Name="empID">
</asp:ControlParameter>
</SELECTPARAMETERS>
</asp:SqlDataSource>
<p>
<asp:GridView
id="GridView1"
runat="server"
DataSourceID="OdbcDataSource1">
</asp:GridView></p>
</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">
Private Sub Page_Load(sender As Object, e As EventArgs)
If (IsPostBack) Then
GridView1.DataBind()
Else
Dim li As ListItem
li = New ListItem("Nancy Davolio", "1",True)
ListBox1.Items.Add(li)
li = New ListItem("Janet Leverling", "3",True)
ListBox1.Items.Add(li)
li = New ListItem("Margaret Peacock","4",True)
ListBox1.Items.Add(li)
li = New ListItem("Michael Suyama", "6",True)
ListBox1.Items.Add(li)
li = New ListItem("Robert King", "7",True)
ListBox1.Items.Add(li)
li = New ListItem("Anne Dodsworth", "9",True)
ListBox1.Items.Add(li)
End If
End Sub ' Page_Load
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>ASP.NET Example</title>
</head>
<body>
<form id="Form1" method="post" runat="server">
<p>Show Orders For:</p>
<p>
<asp:ListBox
id="ListBox1"
runat="server"
AutoPostBack="True">
</asp:ListBox></p>
<asp:SqlDataSource
id="OdbcDataSource1"
runat="server"
ProviderName="System.Data.Odbc"
DataSourceMode="DataSet"
SelectCommand="SELECT OrderID, ShipName FROM Orders WHERE EmployeeID = ?;"
ConnectionString="dsn=MyOdbcDSN;">
<SELECTPARAMETERS>
<asp:ControlParameter
PropertyName="SelectedValue"
ControlID="ListBox1"
Name="empID">
</asp:ControlParameter>
</SELECTPARAMETERS>
</asp:SqlDataSource>
<p>
<asp:GridView
id="GridView1"
runat="server"
DataSourceID="OdbcDataSource1">
</asp:GridView></p>
</form>
</body>
</html>
備註
ControlID屬性是必要的屬性,可識別 Control ControlParameter 物件在執行時間系結的實例。The ControlID property is a required property that identifies the Control instance that the ControlParameter object binds to at run time.
通常 ControlID PropertyName 會針對方法設定和屬性, Evaluate 以正確系結至控制項。Typically, the ControlID and PropertyName properties are set for the Evaluate method to correctly bind to a control. 如果您未設定 ControlID 屬性,則方法會 Evaluate ArgumentException 在呼叫時擲回例外狀況。If you do not set the ControlID property, the Evaluate method throws an ArgumentException exception when called.