ContainsKey Method
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SqlConnectionStringBuilder.ContainsKey Method (String)

 

Determines whether the SqlConnectionStringBuilder contains a specific key.

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

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.

Exception Condition
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

Universal Windows Platform
Available since 10
.NET Framework
Available since 2.0
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