SqlConnectionStringBuilder.ContainsKey(String) Methode

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

Parameters

Retouren

trueals het SqlConnectionStringBuilder een element bevat met de opgegeven sleutel; anders. false

Uitzonderingen

Voorbeelden

In het volgende voorbeeld wordt een SqlConnectionStringBuilder exemplaar gemaakt, enkele eigenschappen ervan ingesteld en vervolgens wordt geprobeerd te bepalen of er verschillende sleutels in het object bestaan door de containskey-methode aan te roepen.

using System.Data.SqlClient;

class Program
{
    static void Main()
    {
        SqlConnectionStringBuilder builder =
            new SqlConnectionStringBuilder(GetConnectionString());
        Console.WriteLine("Connection string = " + builder.ConnectionString);

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

        // Comparison is case insensitive, and synonyms
        // are automatically converted to their "well-known"
        // names.
        Console.WriteLine(builder.ContainsKey("Database"));

        // Keys that are valid but have not been set return true.
        Console.WriteLine(builder.ContainsKey("Max Pool Size"));

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

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

    private static string GetConnectionString()
    {
        // To avoid storing the connection string in your code,
        // you can retrieve it from a configuration file.
        return "Server=(local);Integrated Security=SSPI;" +
            "Initial Catalog=AdventureWorks";
    }
}

Imports System.Data.SqlClient

Module Module1
    Sub Main()
        Dim builder As _
         New SqlConnectionStringBuilder(GetConnectionString())
        Console.WriteLine("Connection string = " & builder.ConnectionString)

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

        ' Comparison is case insensitive, and synonyms
        ' are automatically converted to their "well-known"
        ' names.
        Console.WriteLine(builder.ContainsKey("Database"))

        ' Keys that are valid but have not been set return true.
        Console.WriteLine(builder.ContainsKey("Max Pool Size"))

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

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

    Private Function GetConnectionString() As String
        ' To avoid storing the connection string in your code,
        ' you can retrieve it from a configuration file. 
        Return "Server=(local);Integrated Security=SSPI;" & _
          "Initial Catalog=AdventureWorks"
    End Function
End Module

In het voorbeeld ziet u de volgende uitvoer in het consolevenster:

Connection string = Data Source=(local);Initial Catalog=AdventureWorks;Integrated Security=True
True
True
True
False

Opmerkingen

Omdat de SqlConnectionStringBuilder verzameling een verzameling met vaste grootte van sleutel-waardeparen bevat, bepaalt de ContainsKey methode alleen of een bepaalde sleutelnaam geldig is.

Zie ook

• Verbindingsreeksen in ADO.NET
• overzicht van ADO.NET