SqlConnectionStringBuilder.ContainsKey(String) Metod

Definition

Namnområde:
System.Data.SqlClient
Sammansättning:
System.Data.SqlClient.dll
Sammansättning:
System.Data.dll
Källa:
System.Data.SqlClient.notsupported.cs

Avgör om innehåller SqlConnectionStringBuilder en specifik nyckel.

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

Parametrar

keyword
String

Nyckeln som ska hittas SqlConnectionStringBuilderi .

Returer

Boolean

true SqlConnectionStringBuilder om innehåller ett element som har den angivna nyckeln, falseannars .

Undantag

ArgumentNullException

keyword är null (Nothing i Visual Basic)

Exempel

Följande exempel skapar en SqlConnectionStringBuilder instans, anger några av dess egenskaper och försöker sedan avgöra om det finns olika nycklar i objektet genom att anropa metoden ContainsKey .

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

Exemplet visar följande utdata i konsolfönstret:

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

Kommentarer

Eftersom innehåller SqlConnectionStringBuilder en samling nyckel/värde-par med fast storlek avgör ContainsKey metoden endast om ett visst nyckelnamn är giltigt.

Gäller för

Se även