E.g。使用winamp(至少在Windows上),您可以在后台使用winamp全屏播放游戏,并使用媒体按钮*来控制声音。 Winamp不需要专注,让游戏继续全屏。
我更喜欢用Java编写这个,但这可能不会起作用(在Java afaik中捕获没有焦点的键击已经很困难),所以任何C#解决方案都没问题。
所以基本的问题是:如何在没有焦点的情况下捕获击键?
*)我相信'后退/前进/停止/邮件/搜索/收藏夹/网页/主页'按钮被称为媒体按钮,但欢迎使用更好的名称:)。
答案 0 :(得分:7)
低级别窗口挂钩是一种方法。这是一个article,这里有来自MSDN的更多信息。
这是该代码的部分视图:
private IntPtr LowLevelKeyboardHook(int nCode, WindowsMessages wParam, [In] KBDLLHOOKSTRUCT lParam)
{
bool callNext = true;
bool isKeyDown = (wParam == WindowsMessages.KEYDOWN || wParam == WindowsMessages.SYSKEYDOWN);
bool isKeyUp = (wParam == WindowsMessages.KEYUP || wParam == WindowsMessages.SYSKEYUP);
if ((nCode >= 0) && (isKeyDown || isKeyUp))
{
// the virtual key codes and the winforms Keys have the same enumeration
// so we can freely cast back and forth between them
Keys key = (Keys)lParam.vkCode;
// Do your other processing here...
}
// if any handler returned false, trap the message
return (callNext) ? User32.CallNextHookEx(_mainHook, nCode, wParam, lParam) : _nullNext;
}
/// <summary>
/// Registers the user's LowLevelKeyboardProc with the system in order to
/// intercept any keyboard events before processed in the regular fashion.
/// This can be used to log all keyboard events or ignore them.
/// </summary>
/// <param name="hook">Callback function to call whenever a keyboard event occurs.</param>
/// <returns>The IntPtr assigned by the Windows's sytem that defines the callback.</returns>
private IntPtr RegisterLowLevelHook(LowLevelKeyboardProc hook)
{
IntPtr handle = IntPtr.Zero;
using (Process currentProcess = Process.GetCurrentProcess())
using (ProcessModule currentModule = currentProcess.MainModule)
{
IntPtr module = Kernel32.GetModuleHandle(currentModule.ModuleName);
handle = User32.SetWindowsHookEx(HookType.KEYBOARD_LL, hook, module, 0);
}
return handle;
}
/// <summary>
/// Unregisters a previously registered callback from the low-level chain.
/// </summary>
/// <param name="hook">IntPtr previously assigned to the low-level chain.
/// Users should have stored the value given by
/// <see cref="Drs.Interop.Win32.LowLevelKeyboard.RegisterLowLevelHook"/>,
/// and use that value as the parameter into this function.</param>
/// <returns>True if the hook was removed, false otherwise.</returns>
private bool UnregisterLowLevelHook(IntPtr hook)
{
return User32.UnhookWindowsHookEx(hook);
}
只需实现所需的所有P / Invoke声明,它应该可以正常工作。 我在我的应用程序中使用这种方法,它工作正常。
答案 1 :(得分:0)
在Java中,有两个库可以执行此操作: