Parameter.ToString Parameter.ToString Parameter.ToString Parameter.ToString Method

Определение

Преобразует значение этого экземпляра в эквивалентное ему строковое представление.Converts the value of this instance to its equivalent string representation.

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

Возвраты

Строковое представление значения данного экземпляра.A string representation of the value of this instance.

Примеры

В следующем примере кода показано, как получить доступ к различным свойствам Parameter объекта, включая его Type Name свойства и.The following code example demonstrates how to access various properties of a Parameter object, including its Name and Type properties.

<%@ 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>

Комментарии

ToString Метод возвращаетParameter свойство объекта. NameThe ToString method returns the Name property of the Parameter object. Если объект не имеет имени, ToString возвращает значение String.Empty. ParameterIf the Parameter object has no name, ToString returns String.Empty.

Применяется к

Дополнительно