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OracleConnectionStringBuilder.TryGetValue Method

Note: This method is new in the .NET Framework version 2.0.

Retrieves a value corresponding to the supplied key from this OracleConnectionStringBuilder.

Namespace: System.Data.OracleClient
Assembly: System.Data.OracleClient (in system.data.oracleclient.dll)

'Declaration
Public Overrides Function TryGetValue ( _
	keyword As String, _
	<OutAttribute> ByRef value As Object _
) As Boolean
'Usage
Dim instance As OracleConnectionStringBuilder
Dim keyword As String
Dim value As Object
Dim returnValue As Boolean

returnValue = instance.TryGetValue(keyword, value)
public boolean TryGetValue (
	String keyword, 
	/** @attribute OutAttribute() */ /** @ref */ Object value
)
JScript does not support passing value-type arguments by reference.

Parameters

keyword

The key of the item to retrieve.

value

The value corresponding to keyword.

Return Value

true if keyword was found within the connection string; otherwise, false.

The TryGetValue method lets developers safely retrieve a value from an OracleConnectionStringBuilder without needing to verify that the supplied key name is a valid key name. Because TryGetValue gracefully handles searching for a non-existent key, there is no need to look for the existence of a key before retrieving its value. Calling TryGetValue with a nonexistent key will place the value null (Nothing in Visual Basic) in the value parameter.

The following example demonstrates the behavior of the TryGetValue method.

' You may need to set a reference to the System.Data.OracleClient
' assembly before you can run this sample.
Imports System.Data.OracleClient

Module Module1
    Sub Main()
        Dim builder As New OracleConnectionStringBuilder()
        builder.ConnectionString = GetConnectionString()

        ' Call TryGetValue method for multiple
        ' key names. Note that these keys are converted
        ' to well-known synonynms for data retrieval.
        DisplayValue(builder, "Data Source")
        DisplayValue(builder, "trusted_connection")
        DisplayValue(builder, "InvalidKey")
        DisplayValue(builder, Nothing)

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

    Private Sub DisplayValue( _
     ByVal builder As OracleConnectionStringBuilder, ByVal key As String)
        Dim value As Object = Nothing

        ' Although TryGetValue handles missing keys just fine,
        ' it doesn't handle passing in a null (Nothing in Visual Basic)
        ' key. This example traps for that particular error, but
        ' bubbles any other unknown exceptions back out to the
        ' caller. 
        Try
            If builder.TryGetValue(key, value) Then
                Console.WriteLine("{0='{1' ", key, value)
            Else
                Console.WriteLine("Unable to retrieve value for '{0'", key)
            End If
        Catch ex As ArgumentNullException
            Console.WriteLine("Unable to retrieve value for null key.")
        End Try
    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=OracleDemo;Integrated Security=True"
    End Function
End Module

Windows 98, Windows 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

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

.NET Framework

Supported in: 2.0

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