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SqlConnectionStringBuilder.ContainsKey Method

Determines whether the SqlConnectionStringBuilder contains a specific key.

Namespace:  System.Data.SqlClient
Assembly:  System.Data (in System.Data.dll)

'Declaration
Public Overrides Function ContainsKey ( _
	keyword As String _
) As Boolean

Parameters

keyword
Type: System.String

The key to locate in the SqlConnectionStringBuilder.

Return Value

Type: System.Boolean
true if the SqlConnectionStringBuilder contains an element that has the specified key; otherwise, false.

ExceptionCondition
ArgumentNullException

keyword is null (Nothing in Visual Basic)

Because the SqlConnectionStringBuilder contains a fixed-size collection of key/value pairs, the ContainsKey method determines only if a particular key name is valid.

The following example creates a SqlConnectionStringBuilder instance, sets some of its properties, and then tries to determine whether various keys exist within the object by calling the ContainsKey method.

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

The example displays the following output in the console window:

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

.NET Framework

Supported in: 4.5.2, 4.5.1, 4.5, 4, 3.5, 3.0, 2.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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