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Devart.Common Namespace / DbDump Class / BeginBackupQuery Method / BeginBackupQuery(String,Stream,AsyncCallback,Object) Method
The query, returning data for backup.
The System.IO.Stream to write the script to.
The delegate to call when the asynchronous invoke is complete. If callback is a null reference (Nothing in Visual Basic), the delegate is not called.
State information that is passed on to the delegate.

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    BeginBackupQuery(String,Stream,AsyncCallback,Object) Method
    In This Topic
    Starts an asynchronous invocation of a BackupQuery(String,Stream) method with information for callback function.
    Syntax
    'Declaration
     
    Public Overloads Function BeginBackupQuery( _
       ByVal query As String, _
       ByVal stream As Stream, _
       ByVal callback As AsyncCallback, _
       ByVal stateObject As Object _
    ) As IAsyncResult
    public IAsyncResult BeginBackupQuery( 
       string query,
       Stream stream,
       AsyncCallback callback,
       object stateObject
    )

    Parameters

    query
    The query, returning data for backup.
    stream
    The System.IO.Stream to write the script to.
    callback
    The delegate to call when the asynchronous invoke is complete. If callback is a null reference (Nothing in Visual Basic), the delegate is not called.
    stateObject
    State information that is passed on to the delegate.

    Return Value

    An System.IAsyncResult interface that represents the asynchronous operation started by calling this method.
    Remarks

    BeginBackupQuery(String,Stream,AsyncCallback,Object) method enables you to perform a query backup operation without having current thread blocked. In other words, your program can continue execution while the backup runs in background so you do not have to wait for it.

    To start the query backup operation, you have to call BeginBackupQuery(String,Stream,AsyncCallback,Object) method, which in turn invokes appropriate actions in another thread. Return value of this method must be assigned to an System.IAsyncResult object. After executing this method, the program flow continues.

    When you are ready to finish the query backup operation, call EndBackupQuery. If at the moment you call this function the query backup has not yet been finished, application stops and waits till the function returns.

    Requirements

    Target Platforms: Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

    See Also