xmodmap 组合键 - 如何切换 Fn 行为？

Question

罗技K290键盘通过USB，F键默认是无法访问的，需要先按一下Fn才能使用，实在不行。

Fn单独的键不会触发xev.

按下F1不Fn触发两个键事件，键码 50 ( Shift_L) 和键码 133 ( Super_L) 并在我的 Kubuntu 上显示一条消息“触摸板已禁用”（F1通过 的每个键都显示相同的消息F4）

尽管大多数媒体键都有效，但我更愿意直接访问 F. 键。你知道有什么方法可以切换Fn行为吗？

这里是输出当我按F1无Fn：

KeyPress event, serial 40, synthetic NO, window 0x1a00001,
    root 0x2c6, subw 0x0, time 64638420, (-352,274), root:(1462,621),
    state 0x10, keycode 50 (keysym 0xffe1, Shift_L), same_screen YES,
    XLookupString gives 0 bytes: 
    XmbLookupString gives 0 bytes: 
    XFilterEvent returns: False

KeyPress event, serial 40, synthetic NO, window 0x1a00001,
    root 0x2c6, subw 0x0, time 64638420, (-352,274), root:(1462,621),
    state 0x11, keycode 133 (keysym 0xffeb, Super_L), same_screen YES,
    XLookupString gives 0 bytes: 
    XmbLookupString gives 0 bytes: 
    XFilterEvent returns: False

FocusOut event, serial 40, synthetic NO, window 0x1a00001,
    mode NotifyGrab, detail NotifyAncestor

FocusIn event, serial 40, synthetic NO, window 0x1a00001,
    mode NotifyUngrab, detail NotifyAncestor

KeymapNotify event, serial 40, synthetic NO, window 0x0,
    keys:  4294967238 0   0   0   0   0   4   0   0   0   0   0   0   0   0   0   
           32  0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   

KeyRelease event, serial 40, synthetic NO, window 0x1a00001,
    root 0x2c6, subw 0x0, time 64638436, (-352,274), root:(1462,621),
    state 0x51, keycode 50 (keysym 0xffe1, Shift_L), same_screen YES,
    XLookupString gives 0 bytes: 
    XFilterEvent returns: False

KeyRelease event, serial 40, synthetic NO, window 0x1a00001,
    root 0x2c6, subw 0x0, time 64638436, (-352,274), root:(1462,621),
    state 0x50, keycode 133 (keysym 0xffeb, Super_L), same_screen YES,
    XLookupString gives 0 bytes: 
    XFilterEvent returns: False

MappingNotify event, serial 40, synthetic NO, window 0x0,
    request MappingPointer, first_keycode 0, count 0

而对于F2（仍然没有Fn）：

KeyPress event, serial 40, synthetic NO, window 0x1a00001,
    root 0x2c6, subw 0x0, time 64782724, (-202,438), root:(1491,799),
    state 0x10, keycode 64 (keysym 0xffe9, Alt_L), same_screen YES,
    XLookupString gives 0 bytes: 
    XmbLookupString gives 0 bytes: 
    XFilterEvent returns: False

KeyPress event, serial 40, synthetic NO, window 0x1a00001,
    root 0x2c6, subw 0x0, time 64782724, (-202,438), root:(1491,799),
    state 0x18, keycode 133 (keysym 0xffeb, Super_L), same_screen YES,
    XLookupString gives 0 bytes: 
    XmbLookupString gives 0 bytes: 
    XFilterEvent returns: False

FocusOut event, serial 40, synthetic NO, window 0x1a00001,
    mode NotifyGrab, detail NotifyAncestor

FocusIn event, serial 40, synthetic NO, window 0x1a00001,
    mode NotifyUngrab, detail NotifyAncestor

KeymapNotify event, serial 40, synthetic NO, window 0x0,
    keys:  4294967238 0   0   0   0   0   0   0   1   0   0   0   0   0   0   0   
           32  0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   

KeyRelease event, serial 40, synthetic NO, window 0x1a00001,
    root 0x2c6, subw 0x0, time 64782780, (-202,438), root:(1491,799),
    state 0x58, keycode 64 (keysym 0xffe9, Alt_L), same_screen YES,
    XLookupString gives 0 bytes: 
    XFilterEvent returns: False

KeyRelease event, serial 40, synthetic NO, window 0x1a00001,
    root 0x2c6, subw 0x0, time 64782780, (-202,438), root:(1491,799),
    state 0x50, keycode 133 (keysym 0xffeb, Super_L), same_screen YES,
    XLookupString gives 0 bytes: 
    XFilterEvent returns: False

F1withFn给出了预期的结果：

KeyPress event, serial 40, synthetic NO, window 0x1a00001,
    root 0x2c6, subw 0x0, time 64820204, (-856,-213), root:(1097,247),
    state 0x10, keycode 67 (keysym 0xffbe, F1), same_screen YES,
    XLookupString gives 0 bytes: 
    XmbLookupString gives 0 bytes: 
    XFilterEvent returns: False

KeyRelease event, serial 40, synthetic NO, window 0x1a00001,
    root 0x2c6, subw 0x0, time 64820284, (-856,-213), root:(1097,247),
    state 0x10, keycode 67 (keysym 0xffbe, F1), same_screen YES,
    XLookupString gives 0 bytes: 
    XFilterEvent returns: False

Answer 1

xev无法显示桌面环境捕获的事件。测试按键的更好方法是使用showkey命令（在 Linux 控制台，而不是在 X11 内）。我猜测操作系统实际上正在接收 Shift + Super + 某些键组合。

虽然您可以想象将所述组合重新映射为 F 键，但这可能会很麻烦：您必须“释放”Shift 键（因为键盘模拟按下它），并且使 Shift+F1 工作会更加复杂，因为如果之前按住 Shift 键，则需要进行跟踪。

这个问题在笔记本电脑上很常见，笔记本电脑通常有切换多媒体热键的组合键，或者 BIOS/固件中的选项。但正如您提到的，这与特定型号的外部键盘有关，在网上查找时我发现了这个项目：

https://github.com/milgner/k290-fnkeyctl

该项目的描述称其“重新配置了 Logitech K290 键盘上功能键的工作方式”，因此可能值得一试。