下面的代碼是如何檢測(cè)幾乎所有當(dāng)前按下的鍵,而不僅僅是換檔鑰匙。
private KeyMessageFilter m_filter = new KeyMessageFilter();private void Form1_Load(object sender, EventArgs e){
Application.AddMessageFilter(m_filter);}public class KeyMessageFilter : IMessageFilter{
private const int WM_KEYDOWN = 0x0100;
private const int WM_KEYUP = 0x0101;
private bool m_keyPressed = false;
private Dictionary<Keys, bool> m_keyTable = new Dictionary<Keys, bool>();
public Dictionary<Keys, bool> KeyTable
{
get { return m_keyTable; }
private set { m_keyTable = value; }
}
public bool IsKeyPressed()
{
return m_keyPressed;
}
public bool IsKeyPressed(Keys k)
{
bool pressed = false;
if (KeyTable.TryGetValue(k, out pressed))
{
return pressed;
}
return false;
}
public bool PreFilterMessage(ref Message m)
{
if (m.Msg == WM_KEYDOWN)
{
KeyTable[(Keys)m.WParam] = true;
m_keyPressed = true;
}
if (m.Msg == WM_KEYUP)
{
KeyTable[(Keys)m.WParam] = false;
m_keyPressed = false;
}
return false;
}}