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OracleConnectionStringBuilder.TryGetValue Method

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)

Parameters

keyword
Type: System.String

The key of the item to retrieve.

value
Type: System.Object%

The value corresponding to keyword.

Return Value

Type: System.Boolean
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 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

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

.NET Framework

Supported in: 3.5, 3.0, 2.0

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