例如使用 winamp(至少在 Windows 上),您可以在后台使用 winamp 全屏玩游戏,并使用媒体按钮*控制声音。 Winamp 不需要获得焦点,允许游戏继续全屏。
我更喜欢用 Java 编写,但这可能行不通(在 Java afaik 中捕获没有焦点的击键已经很困难),因此任何 C# 解决方案也可以。
所以基本问题是: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/Collection 夹/网络/主页”按钮称为媒体按钮,但欢迎使用更好的名称:)。
最佳答案
Low-Level windows hooks 是一种方法。这是一个article这是来自 MSDN 的更多信息.
这是该代码的部分 View :
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);
}
只要实现所有需要的 P/Invoke 声明,它就应该可以工作。 我在我的应用程序中使用了这种方法,并且效果很好。
关于c# - 捕获没有焦点的击键,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/1161053/