OdbcConnectionStringBuilder.Clear Метод

Определение

Пространство имен:

System.Data.Odbc

Сборка:

System.Data.Odbc.dll

Пакет:

System.Data.Odbc v8.0.0

Исходный код:

OdbcConnectionStringbuilder.cs

Удаляет содержимое экземпляра OdbcConnectionStringBuilder.

public:
 override void Clear();

public override void Clear ();

override this.Clear : unit -> unit

Public Overrides Sub Clear ()

Примеры

using System.Data.Odbc;
class Program
{
    static void Main()
    {
        OdbcConnectionStringBuilder builder = new OdbcConnectionStringBuilder();

        // Call the Add method to explicitly add key/value
        // pairs to the internal collection.
        builder.Driver = "Microsoft Excel Driver (*.xls)";
        builder["Dbq"] = "C:\\Data.xls";
        builder["DriverID"] = "790";
        builder["DefaultDir"] = "C:\\";

        // Dump the contents of the "filled-in" OdbcConnectionStringBuilder
        // to the Console window:
        DumpBuilderContents(builder);

        // Clear current values and reset known keys to their
        // default values.
        builder.Clear();

        // Dump the contents of the newly emptied OdbcConnectionStringBuilder
        // to the console window.
        DumpBuilderContents(builder);

        Console.WriteLine("Press Enter to continue.");
        Console.ReadLine();
    }

    private static void DumpBuilderContents(OdbcConnectionStringBuilder builder)
    {
        Console.WriteLine("=================");
        Console.WriteLine("builder.ConnectionString = " + builder.ConnectionString);
        foreach (string key in builder.Keys)
        {
            Console.WriteLine(key + "=" + builder[key].ToString());
        }
    }
}

Imports System.Data.Odbc    

Module Module1
  Sub Main()
    Dim builder As New OdbcConnectionStringBuilder()

    ' Call the Add method to explicitly add key/value
    ' pairs to the internal collection.
    builder.Driver = "Microsoft Excel Driver (*.xls)"
    builder("Dbq") = "C:\Data.xls"
    builder("DriverID") = "790"
    builder("DefaultDir") = "C:\"

    ' Dump the contents of the "filled-in" OdbcConnectionStringBuilder
    ' to the console window.
    DumpBuilderContents(builder)

    ' Clear current values and reset known keys to their
    ' default values.
    builder.Clear()

    ' Dump the contents of the newly emptied 
    ' OdbcConnectionStringBuilder
    ' to the console window.
    DumpBuilderContents(builder)

    Console.WriteLine("Press Enter to continue.")
    Console.ReadLine()
  End Sub

  Private Sub DumpBuilderContents(ByVal builder As OdbcConnectionStringBuilder)
    Console.WriteLine("=================")
    Console.WriteLine("builder.ConnectionString = " & builder.ConnectionString)
    For Each key As String In builder.Keys
      Console.WriteLine(key & "=" & builder.Item(key).ToString)
    Next
  End Sub
End Module

Комментарии

Метод Clear удаляет все пары "ключ-значение" из OdbcConnectionStringBuilder и сбрасывает Driver свойства и Dsn до значений по умолчанию. Метод Clear также задает Count для свойства значение 0, а для ConnectionString свойства — пустую строку.

См. также раздел

• Построители строк подключения
• Строки подключения в ADO.NET