有时候，我们需要在 console 中检查是否有按键按下，对于c语言来说，有 kbhit 和 keypressed, 但是Delphi库中没有对应的现成函数。
经过搜索，最终找到了一段代码【参考１】，根据这段代码，编写下面的测试程序：
program Project5;
{$APPTYPE CONSOLE}
{$R *.res}
uses
System.SysUtils,Windows;
function KeyPressed:Boolean;
var
lpNumberOfEvents : DWORD;
lpBuffer : TInputRecord;
lpNumberOfEventsRead : DWORD;
nStdHandle : THandle;
begin
Result:=false;
//get the console handle
nStdHandle := GetStdHandle(STD_INPUT_HANDLE);
lpNumberOfEvents:=0;
//get the number of events
GetNumberOfConsoleInputEvents(nStdHandle,lpNumberOfEvents);
if lpNumberOfEvents<> 0 then
begin
//retrieve the event
PeekConsoleInput(nStdHandle,lpBuffer,1,lpNumberOfEventsRead);
if lpNumberOfEventsRead <> 0 then
begin
if lpBuffer.EventType = KEY_EVENT then //is a Keyboard event?
begin
if lpBuffer.Event.KeyEvent.bKeyDown then //the key was pressed?
Result:=true
else
FlushConsoleInputBuffer(nStdHandle); //flush the buffer
end
else
FlushConsoleInputBuffer(nStdHandle);//flush the buffer
end;
end;
end;
var
i:integer;
begin
while (keypressed()=false) do
begin
write('waiting ');
writeln(i);
sleep(1000);
inc(i);
end;
end.
运行结果：
参考：
1.https://stackoverflow.com/questions/5845080/how-i-can-implement-a-iskeypressed-function-in-a-delphi-console-application
