Opening and Closing Mixer Devices (Windows CE 5.0)
When you want to use a mixer device, you can simply begin using it or you can explicitly open the device before using it.
Explicitly opening a mixer device offers two main benefits:
- It guarantees the continued existence of that mixer device.
- It lets you receive notification of audio line and control changes.
You can use the mixerOpen function to explicitly open a mixer device. This function takes as parameters a device identifier, a pointer to a memory location, and other values unique to each type of device.
The memory location is filled with a device handle. Use this device handle to identify the open mixer device when calling other audio mixer functions. As long as a handle of a mixer device exists, the device continues to exist in the system.
If a configuration change occurs to the mixer device and it has not been explicitly opened, your application might suddenly be unable to access it.
**Note **The difference between device identifiers and device handles is important. Device handles are returned when you open a device driver using mixerOpen.
You can use the mixerClose function to close a mixer device. You should close the device after you finish using it.
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