ControlParameter.ControlID Vlastnost

Definice

Určuje název ovládacího prvku, ke kterému se ControlParameter objekt váže.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

Hodnota vlastnosti

String

stringKterý představuje název ovládacího prvku webového serveru.A string that represents the name of a Web server control.

Atributy

Příklady

Následující příklad kódu ukazuje, jak použít ControlParameter objekt pro svázání dat zobrazených v ListBox ovládacím prvku s vybranou hodnotou DropDownList ovládacího prvku v deklarativním scénáři.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. ControlParameterObjekt je přidán do SelectParameters kolekce SqlDataSource ovládacího prvku ve formuláři a odpovídá @Title zástupnému textu ve SelectCommand Vlastnosti.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>

Následující příklad kódu ukazuje, jak nastavit ControlID PropertyName vlastnosti a pro identifikaci ovládacího prvku, ControlParameter na který je objekt svázán.The following code example demonstrates how to set the ControlID and PropertyName properties to identify the control that a ControlParameter object is bound to. Tento příklad naplní ListBox ovládací prvek hodnotami.The example populates a ListBox control with values. SelectedValueVlastnost ListBox ovládacího prvku slouží k filtrování dat načtených SqlDataSource ovládacím prvkem a zobrazeného GridView ovládacím prvkem.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>

Poznámky

ControlIDVlastnost je povinná vlastnost, která identifikuje Control instanci, na kterou se ControlParameter objekt váže v době běhu.The ControlID property is a required property that identifies the Control instance that the ControlParameter object binds to at run time.

Obvykle ControlID PropertyName jsou vlastnosti a nastaveny pro Evaluate metodu pro správné vázání k ovládacímu prvku.Typically, the ControlID and PropertyName properties are set for the Evaluate method to correctly bind to a control. Pokud vlastnost nenastavíte ControlID , Evaluate ArgumentException při volání metody vyvolá výjimku.If you do not set the ControlID property, the Evaluate method throws an ArgumentException exception when called.

Platí pro

Viz také