Specifies the repeat count, scan code, extended-key flag, context code, previous key-state flag, and transition-state flag, as shown in the following table.
Specifies the repeat count for the current message. The value is the number of times the keystroke is autorepeated as a result of the user holding down the key. If the keystroke is held long enough, multiple messages are sent. However, the repeat count is not cumulative.
Specifies the scan code. The value depends on the OEM.
Specifies whether the key is an extended key, such as the right-hand ALT and CTRL keys that appear on an enhanced 101- or 102-key keyboard. The value is 1 if it is an extended key; otherwise, it is 0.
Reserved; do not use.
Specifies the context code. The value is 1 if the ALT key is held down while the key is pressed; otherwise, the value is 0.
Specifies the previous key state. The value is 1 if the key is down before the message is sent, or it is 0 if the key is up.
Specifies the transition state. The value is 1 if the key is being released, or it is 0 if the key is being pressed.