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RemoteOrderDisplay.TransactionDisplay Method

  • Article

2/27/2008

Enters or exits transaction mode for the specified video unit(s).

Namespace: Microsoft.PointOfService
Assembly: Microsoft.PointOfService (in microsoft.pointofservice.dll)

Syntax

'Declaration
Public MustOverride Sub TransactionDisplay ( _
    units As DeviceUnits, _
    transactionFunction As RemoteOrderDisplayTransaction _
)

public abstract void TransactionDisplay (
    DeviceUnits units,
    RemoteOrderDisplayTransaction transactionFunction
)

public:
virtual void TransactionDisplay (
    DeviceUnits units, 
    RemoteOrderDisplayTransaction transactionFunction
) abstract

public abstract void TransactionDisplay (
    DeviceUnits units, 
    RemoteOrderDisplayTransaction transactionFunction
)

public abstract function TransactionDisplay (
    units : DeviceUnits, 
    transactionFunction : RemoteOrderDisplayTransaction
)

Parameters

  • units
    The units to operate on.
  • transactionFunction
    Transaction control function.

Remarks

If transactionFunction is Transaction, then transaction mode is entered. Later calls to ClearVideo, ClearVideoRegion, CopyVideoRegion, DisplayData, DrawBox, RestoreVideoRegion, SaveVideoRegion, and UpdateVideoRegionAttribute will buffer the display data (either at the video unit or the service object, depending on the display capabilities) until TransactionDisplay is called by using the transactionFunction parameter set to Normal. (In this case, the display methods only validate the method parameters and buffer the data. They do not start displaying. Also, the value of the AsyncMode property does not affect their operation: No OutputID is assigned to the request, nor will an OutputCompleteEvent event be raised.)

If transactionFunction is Normal, then transaction mode is exited. If some data was buffered by calls to the ClearVideo, ClearVideoRegion, CopyVideoRegion, DisplayData, DrawBox, RestoreVideoRegion, SaveVideoRegion, and UpdateVideoRegionAttribute methods, then the buffered data is displayed. The transaction is treated as one message.

TransactionDisplay is performed synchronously if AsyncMode is false, and asynchronously if AsyncMode is true.

Calling the ClearOutput method cancels transaction mode for the unit specified by the CurrentUnitId property. Any buffered print lines are also cleared.

TransactionDisplay may cause a PosControlException to be thrown with the following ErrorCode:

Value

Description

Busy

Cannot perform while output is in progress for one of the video units indicated in units. The ErrorUnits and ErrorString properties are updated. (Can only occur if AsyncMode is false and function is Normal.)

Failure

An error occurred while communicating with one of the video units specified by units. The ErrorUnits and ErrorString properties are updated before return.

Thread Safety

Any public static (Shared in Visual Basic) members of this type are thread-safe. Any instance members are not guaranteed to be thread-safe.

See Also

Reference

RemoteOrderDisplay Class
RemoteOrderDisplay Members
Microsoft.PointOfService Namespace
RemoteOrderDisplay.ClearVideo Method
RemoteOrderDisplay.ClearVideoRegion Method
RemoteOrderDisplay.CopyVideoRegion Method
RemoteOrderDisplay.DisplayData Method
RemoteOrderDisplay.DrawBox Method
RemoteOrderDisplay.RestoreVideoRegion Method
RemoteOrderDisplay.SaveVideoRegion Method
UpdateVideoRegionAttribute