OdbcConnectionStringBuilder.ContainsKey(String) Metodo

Definizione

Spazio dei nomi:

System.Data.Odbc

Assembly:

System.Data.Odbc.dll

Pacchetto:

System.Data.Odbc v9.0.0-preview.3.24172.9

Origine:

OdbcConnectionStringbuilder.cs

Determina se l'oggetto OdbcConnectionStringBuilder contiene una chiave specifica.

public:
 override bool ContainsKey(System::String ^ keyword);

public override bool ContainsKey (string keyword);

override this.ContainsKey : string -> bool

Public Overrides Function ContainsKey (keyword As String) As Boolean

Parametri

keyword

String

Chiave da individuare in OdbcConnectionStringBuilder.

Restituisce

Boolean

true se la classe OdbcConnectionStringBuilder contiene un elemento con la chiave specificata; in caso contrario, false.

Eccezioni

ArgumentNullException

keyword è null (Nothing in Visual Basic).

Esempio

L'esempio seguente crea un'istanza OdbcConnectionStringBuilder , imposta alcune delle relative proprietà e quindi tenta di determinare se esistono diverse chiavi all'interno dell'oggetto chiamando il ContainsKey metodo .

using System.Data.Odbc;

class Program
{
    static void Main()
    {
        OdbcConnectionStringBuilder  builder = new OdbcConnectionStringBuilder();
        builder.Driver = "Microsoft Visual FoxPro Driver";
        builder["SourceType"] = "DBC";

        // Keys that you have provided return true.
        Console.WriteLine(builder.ContainsKey("SourceType"));

        // Comparison is case insensitive.
        Console.WriteLine(builder.ContainsKey("sourcetype"));

        // Keys added by the provider return false. This method
        // only examines keys added explicitly.
        Console.WriteLine(builder.ContainsKey("DNS"));

        // Keys that do not exist return false.
        Console.WriteLine(builder.ContainsKey("MyKey"));

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

Imports System.Data.Odbc    

Module Module1
  Sub Main()
    Dim builder As New OdbcConnectionStringBuilder()
    builder.Driver = "Microsoft Visual FoxPro Driver"
    builder("SourceType") = "DBC"

    ' Keys you have provided return true.
    Console.WriteLine(builder.ContainsKey("SourceType"))

    ' Comparison is case insensitive.
    Console.WriteLine(builder.ContainsKey("sourcetype"))

    ' Keys added by the provider return false. This method
    ' only examines keys added explicitly.
    Console.WriteLine(builder.ContainsKey("DNS"))

    ' Keys that do not exist return false.
    Console.WriteLine(builder.ContainsKey("MyKey"))

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

Vedi anche

• Generatori di stringhe di connessione
• Stringhe di connessione in ADO.NET