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Windows Mobile 6.5
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This function swaps the specified active call with the specified call on consultation hold.

LONG WINAPI lineSwapHold(
  HCALL hActiveCall,
  HCALL hHeldCall 


Handle to the active call. The application must be an owner of the call. The call state of hActiveCall must be connected.


Handle to the consultation call. The application must be an owner of the call. The call state of hHeldCall can be onHoldPendingTransfer, onHoldPendingConference, or onHold.

Returns a positive request identifier if the function is completed asynchronously, or a negative error number if an error occurs. The dwParam2 parameter of the corresponding LINE_REPLY message is zero if the function succeeds or it is a negative error number if an error occurs. The following table shows the return values for this function.

Value Description


A call handle is invalid.


The operation is unavailable because this function is not supported by code division multiple access (CDMA).

CDMA does not provide the necessary functionality to support the following TAPI functions:

Some cellular carriers provide equivalent functionality through the flash feature, which with TAPI 2.2 can be accessed with the lineGenerateDigits function. Because the exact flash sequences are controlled by the cellular providers, the application must be completely aware of the necessary codes implemented by the cellular providers.


The call state is invalid.


The operation failed.


Not enough memory is available.


The resources are unavailable.


The application is not an owner of this call.


A parameter is uninitialized.

Swapping the active call with the call on consultation hold allows the application to alternate or toggle between these two calls. This is typical in call waiting.

This function is for TAPI version 2.0 and later.

Windows Embedded CEWindows CE 1.0 and later
Windows MobileWindows Mobile Version 5.0 and later

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