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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)

Public Overrides Function TryGetValue ( _
	keyword As String, _
	<OutAttribute> ByRef value As Object _
) As Boolean


Type: System.String

The key of the item to retrieve.

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.")
    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.  
            If builder.TryGetValue(key, value) Then
                Console.WriteLine("{0}='{1}' ", key, value)
                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

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0
© 2015 Microsoft