Parameter.ToString Methode

Definition

Konvertiert den Wert dieser Instanz in die entsprechende Zeichenfolgendarstellung.

public:
 override System::String ^ ToString();
public override string ToString ();
override this.ToString : unit -> string
Public Overrides Function ToString () As String

Gibt zurück

Eine Zeichenfolgendarstellung des Werts dieser Instanz.

Beispiele

Im folgenden Codebeispiel wird veranschaulicht, wie Sie auf verschiedene Eigenschaften eines Parameter Objekts zugreifen, einschließlich seiner Name Eigenschaften und Type .

<%@ 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, EventArgs e) {

    SqlDataSource sqlSource = 
        new SqlDataSource(ConfigurationManager.ConnectionStrings["MyNorthwind"].ConnectionString,
                          "SELECT * From Employees where EmployeeID = @employee");
    
    // When a Parameter is not named, Name returns String.Empty.
    Parameter userID = new Parameter();

    if (userID.Name.Equals(String.Empty)) {
        Response.Write("Name is Empty<br />");
    }

    if (null == userID.Name) {
        Response.Write("Name is Null<br />");
    }

    // Set the Name of the Parameter
    userID.Name = "employee";

    // The Parameter.DefaultValue property is used to bind a static String.
    userID.DefaultValue = "3";

    // The ToString method returns the Name of the Parameter.
    Response.Write(userID.ToString() + "<br />");
    Response.Write(userID.Name + "<br />");

    // The default Type of the Parameter is TypeCode.Object
    Response.Write(userID.Type.ToString() + "<br />");

    sqlSource.SelectParameters.Add(userID);
    Page.Controls.Add(sqlSource);

    GridView grid = new GridView();
    grid.DataSource = sqlSource;
    grid.DataBind();

    PlaceHolder1.Controls.Add(grid);
}
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
    <head runat="server">
    <title>ASP.NET Example</title>
</head>
<body>
        <form id="form1" runat="server">

       <asp:PlaceHolder id="PlaceHolder1" runat="server"/>

        </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">
 Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)

    Dim sqlSource As New SqlDataSource
    sqlSource.ConnectionString = _
        ConfigurationManager.ConnectionStrings("MyNorthwind").ConnectionString

    sqlSource.SelectCommand = _
        "SELECT * From Employees where EmployeeID = @employee"


    ' When a Parameter is not named, Name returns String.Empty.
    Dim userID As New Parameter()

    If userID.Name Is String.Empty Then
        Response.Write("Name is Empty<br />")
    End If

    If userID.Name Is Nothing Then
        Response.Write("Name is Null<br />")
    End If

    ' Set the Name of the Parameter
    userID.Name = "employee"

    ' The Parameter.DefaultValue property is used to bind a static String
    userID.DefaultValue = "3"

    ' The ToString method returns the Name of the Parameter
    Response.Write(userID.ToString & "<br />")
    Response.Write(userID.Name & "<br />")

    ' The default Type of the Parameter is TypeCode.Object
    Response.Write(userID.Type.ToString & "<br />")

    sqlSource.SelectParameters.Add(userID)
    Page.Controls.Add(sqlSource)

    Dim grid As New GridView()
    grid.DataSource = sqlSource
    grid.DataBind()

    PlaceHolder1.Controls.Add(grid)

 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" runat="server">

       <asp:PlaceHolder id="PlaceHolder1" runat="server"/>

        </form>
    </body>
</html>

Hinweise

Die ToString -Methode gibt die Name -Eigenschaft des Parameter -Objekts zurück. Wenn das Parameter Objekt keinen Namen hat, ToString wird zurückgegeben String.Empty.

Gilt für:

Weitere Informationen