www.pudn.com > HIDClass.zip > _#HID_Overview.RTF

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${\footnote $ HID - Overview} 
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The HID component gives you complete access to all HID devices of Windows 98, Windows 98 SE and Windows 2000. A HID device is a USB device which you can interact with. Most of the USB devices are HID.  
Keyboard, mice or scanners are definitely HID. A USB Hub is not HID. There is no need to touch it to make it work.  
Some non USB devices are added to HID by a legacy driver.\par 
 
The main feature of USB is the hotplugging of the devices. Consequently the HID component is a controller component which handles all the HID device plugs and unplugs. You will therefore only need a single instance of the {\uldb HID component\v IDH_Class_TJvHidDeviceController} in your program.  
Each individual HID device is represented by an instance of a HID device object. The HID controller holds a list of all HID device objects. When a HID device is plugged Windows sends a WM_DEVICECHANGE event.  
The HID component catches this event and adds a new instance of a HID device object to its list of  HID devices.\par 
 
Now you can ask the HID component to hand out one of its {\uldb HID device objects\v IDH_Class_TJvHidDevice}. With this HID device object you can then access the individual device. When you are finished with the device hand back the HID device object to the HID component.\page 
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