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Devart.Common Namespace / DbDump Class / BeginBackupQuery Method / BeginBackupQuery(String,TextWriter,AsyncCallback,Object) Method
The query, returning data for backup.
The System.IO.TextWriter 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.

BeginBackupQuery(String,TextWriter,AsyncCallback,Object) Method
Starts an asynchronous invocation of a BackupQuery(String,TextWriter) method with information for callback function.
Syntax
'Declaration
 
Public Overloads Function BeginBackupQuery( _
   ByVal query As String, _
   ByVal writer As TextWriter, _
   ByVal callback As AsyncCallback, _
   ByVal stateObject As Object _
) As IAsyncResult
 

Parameters

query
The query, returning data for backup.
writer
The System.IO.TextWriter 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,TextWriter,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,TextWriter,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