KeyPressed

Syntax

dword keypressed();

Function

This function returns the key code of a currently pressed key. If no key is being pressed it returns 0.. For example, pressing of a key can be queried in a timer function. The reaction can also be to letting go of a key.

Parameters

—

Return Values

Key code of pressed key. If the 8 lower bits do not equal 0,keypressedreturns the ASCII code of the next key in the keyboard buffer. If the 8 lower bits do not equal 0, the 8 upper bits represent the extended key code (see IBM PC Technical Reference Manual).

variables{message 0x1A0 msg; // intialises a message with the// name msg and identifier 0x1A0msTimer myTimer;  // timer with millisecond resolutionint running;  // memorises the first keypress to// bypass the key repeatint counter;  // message counter}on timer myTimer{if (keypressed())   // if key is pressed ...{counter++;   // increment counter by 1msg.byte(0) = counter; // write the counter reading// into the 1. byte of the messageoutput(msg);  // send the message to the bussetTimer(myTimer, 100); // set a timer to 100 ms}else      // if key is released...{running = 0;  // wait until new keypress}}on key 'r'{if (running == 1) return; // inhibit key repeatsetTimer (myTimer,0);  // start timerrunning = 1;   // memorise of first keypress}