如何将ASCII字符转换为CGKeyCode？

I need a function that, given a character, returns the CGKeyCode associated with the position of that character on the current keyboard layout. E.g., given "b", it should return kVK_ANSI_B if using U.S. QWERTY, or kVK_ANSI_N if using Dvorak.

我需要一个函数，给定一个字符，返回与当前键盘布局上该字符的位置相关联的CGKeyCode。例如，给定“b”，如果使用美国QWERTY则应返回kVK_ANSI_B，如果使用Dvorak则应返回kVK_ANSI_N。

The Win32 API has the function VkKeyScan() for this purpose; X11 has the function XStringToKeySym(). Is there such a function in the CG API?

Win32 API具有用于此目的的函数VkKeyScan（）; X11具有XStringToKeySym（）函数。 CG API中有这样的功能吗？

I need this in order to pass a parameter to CGEventCreateKeyboardEvent(). I've tried using CGEventKeyboardSetUnicodeString() instead, but that apparently does not support modifier flags (which I need).

我需要这个以便将参数传递给CGEventCreateKeyboardEvent（）。我尝试使用CGEventKeyboardSetUnicodeString（），但显然不支持修饰符标志（我需要）。

I have searched extensively for this but cannot find a decent answer. Currently I am using the following code (found online), which works, but is not exactly elegant (and rather difficult to decipher how to simplify) and I would prefer not to use it in production code:

我已经广泛搜索了这个但是找不到合适的答案。目前我正在使用以下代码（在线发现），它有效，但并不完全优雅（而且很难解释如何简化），我宁愿不在生产代码中使用它：

#include <stdint.h>
#include <stdio.h>
#include <ApplicationServices/ApplicationServices.h>

CGKeyCode keyCodeForCharWithLayout(const char c,
                                   const UCKeyboardLayout *uchrHeader);

CGKeyCode keyCodeForChar(const char c)
{
    CFDataRef currentLayoutData;
    TISInputSourceRef currentKeyboard = TISCopyCurrentKeyboardInputSource();

    if (currentKeyboard == NULL) {
        fputs("Could not find keyboard layout\n", stderr);
        return UINT16_MAX;
    }

    currentLayoutData = TISGetInputSourceProperty(currentKeyboard,
                                                kTISPropertyUnicodeKeyLayoutData);
    CFRelease(currentKeyboard);
    if (currentLayoutData == NULL) {
        fputs("Could not find layout data\n", stderr);
        return UINT16_MAX;
    }

    return keyCodeForCharWithLayout(c,
           (const UCKeyboardLayout *)CFDataGetBytePtr(currentLayoutData));
}

/* Beware! Messy, incomprehensible code ahead!
 * TODO: XXX: FIXME! Please! */
CGKeyCode keyCodeForCharWithLayout(const char c,
                                   const UCKeyboardLayout *uchrHeader)
{
    uint8_t *uchrData = (uint8_t *)uchrHeader;
    UCKeyboardTypeHeader *uchrKeyboardList = uchrHeader->keyboardTypeList;

    /* Loop through the keyboard type list. */
    ItemCount i, j;
    for (i = 0; i < uchrHeader->keyboardTypeCount; ++i) {
        /* Get a pointer to the keyToCharTable structure. */
        UCKeyToCharTableIndex *uchrKeyIX = (UCKeyToCharTableIndex *)
        (uchrData + (uchrKeyboardList[i].keyToCharTableIndexOffset));

        /* Not sure what this is for but it appears to be a safeguard... */
        UCKeyStateRecordsIndex *stateRecordsIndex;
        if (uchrKeyboardList[i].keyStateRecordsIndexOffset != 0) {
            stateRecordsIndex = (UCKeyStateRecordsIndex *)
                (uchrData + (uchrKeyboardList[i].keyStateRecordsIndexOffset));

            if ((stateRecordsIndex->keyStateRecordsIndexFormat) !=
                kUCKeyStateRecordsIndexFormat) {
                stateRecordsIndex = NULL;
            }
        } else {
            stateRecordsIndex = NULL;
        }

        /* Make sure structure is a table that can be searched. */
        if ((uchrKeyIX->keyToCharTableIndexFormat) != kUCKeyToCharTableIndexFormat) {
            continue;
        }

        /* Check the table of each keyboard for character */
        for (j = 0; j < uchrKeyIX->keyToCharTableCount; ++j) {
            UCKeyOutput *keyToCharData =
                (UCKeyOutput *)(uchrData + (uchrKeyIX->keyToCharTableOffsets[j]));

            /* Check THIS table of the keyboard for the character. */
            UInt16 k;
            for (k = 0; k < uchrKeyIX->keyToCharTableSize; ++k) {
                /* Here's the strange safeguard again... */
                if ((keyToCharData[k] & kUCKeyOutputTestForIndexMask) ==
                    kUCKeyOutputStateIndexMask) {
                    long keyIndex = (keyToCharData[k] & kUCKeyOutputGetIndexMask);
                    if (stateRecordsIndex != NULL &&
                        keyIndex <= (stateRecordsIndex->keyStateRecordCount)) {
                        UCKeyStateRecord *stateRecord = (UCKeyStateRecord *)
                                                        (uchrData +
                        (stateRecordsIndex->keyStateRecordOffsets[keyIndex]));

                        if ((stateRecord->stateZeroCharData) == c) {
                            return (CGKeyCode)k;
                        }
                    } else if (keyToCharData[k] == c) {
                        return (CGKeyCode)k;
                    }
                } else if (((keyToCharData[k] & kUCKeyOutputTestForIndexMask)
                            != kUCKeyOutputSequenceIndexMask) &&
                           keyToCharData[k] != 0xFFFE &&
                           keyToCharData[k] != 0xFFFF &&
                           keyToCharData[k] == c) {
                    return (CGKeyCode)k;
                }
            }
        }
    }

    return UINT16_MAX;
}

Is there a.) (preferably) a standard function I am overlooking, or b.) (almost certainly) a more elegant way write my own?

是否有一个。）（最好）一个我忽略的标准功能，或者b。）（几乎可以肯定）一种更优雅的方式来写我自己的？

4 个解决方案

#1

This is what I ended up using. Much cleaner.

这就是我最终使用的。更清洁。

#include <CoreFoundation/CoreFoundation.h>
#include <Carbon/Carbon.h> /* For kVK_ constants, and TIS functions. */

/* Returns string representation of key, if it is printable.
 * Ownership follows the Create Rule; that is, it is the caller's
 * responsibility to release the returned object. */
CFStringRef createStringForKey(CGKeyCode keyCode)
{
    TISInputSourceRef currentKeyboard = TISCopyCurrentKeyboardInputSource();
    CFDataRef layoutData =
        TISGetInputSourceProperty(currentKeyboard,
                                  kTISPropertyUnicodeKeyLayoutData);
    const UCKeyboardLayout *keyboardLayout =
        (const UCKeyboardLayout *)CFDataGetBytePtr(layoutData);

    UInt32 keysDown = 0;
    UniChar chars[4];
    UniCharCount realLength;

    UCKeyTranslate(keyboardLayout,
                   keyCode,
                   kUCKeyActionDisplay,
                   0,
                   LMGetKbdType(),
                   kUCKeyTranslateNoDeadKeysBit,
                   &keysDown,
                   sizeof(chars) / sizeof(chars[0]),
                   &realLength,
                   chars);
    CFRelease(currentKeyboard);    

    return CFStringCreateWithCharacters(kCFAllocatorDefault, chars, 1);
}

/* Returns key code for given character via the above function, or UINT16_MAX
 * on error. */
CGKeyCode keyCodeForChar(const char c)
{
    static CFMutableDictionaryRef charToCodeDict = NULL;
    CGKeyCode code;
    UniChar character = c;
    CFStringRef charStr = NULL;

    /* Generate table of keycodes and characters. */
    if (charToCodeDict == NULL) {
        size_t i;
        charToCodeDict = CFDictionaryCreateMutable(kCFAllocatorDefault,
                                                   128,
                                                   &kCFCopyStringDictionaryKeyCallBacks,
                                                   NULL);
        if (charToCodeDict == NULL) return UINT16_MAX;

        /* Loop through every keycode (0 - 127) to find its current mapping. */
        for (i = 0; i < 128; ++i) {
            CFStringRef string = createStringForKey((CGKeyCode)i);
            if (string != NULL) {
                CFDictionaryAddValue(charToCodeDict, string, (const void *)i);
                CFRelease(string);
            }
        }
    }

    charStr = CFStringCreateWithCharacters(kCFAllocatorDefault, &character, 1);

    /* Our values may be NULL (0), so we need to use this function. */
    if (!CFDictionaryGetValueIfPresent(charToCodeDict, charStr,
                                       (const void **)&code)) {
        code = UINT16_MAX;
    }

    CFRelease(charStr);
    return code;
}

#2

+ (NSString *)keyStringFormKeyCode:(CGKeyCode)keyCode
{
    // Proper key detection seems to want a switch statement, unfortunately
    switch (keyCode)
    {
        case 0: return @"a";
        case 1: return @"s";
        case 2: return @"d";
        case 3: return @"f";
        case 4: return @"h";
        case 5: return @"g";
        case 6: return @"z";
        case 7: return @"x";
        case 8: return @"c";
        case 9: return @"v";
            // what is 10?
        case 11: return @"b";
        case 12: return @"q";
        case 13: return @"w";
        case 14: return @"e";
        case 15: return @"r";
        case 16: return @"y";
        case 17: return @"t";
        case 18: return @"1";
        case 19: return @"2";
        case 20: return @"3";
        case 21: return @"4";
        case 22: return @"6";
        case 23: return @"5";
        case 24: return @"=";
        case 25: return @"9";
        case 26: return @"7";
        case 27: return @"-";
        case 28: return @"8";
        case 29: return @"0";
        case 30: return @"]";
        case 31: return @"o";
        case 32: return @"u";
        case 33: return @"[";
        case 34: return @"i";
        case 35: return @"p";
        case 36: return @"RETURN";
        case 37: return @"l";
        case 38: return @"j";
        case 39: return @"'";
        case 40: return @"k";
        case 41: return @";";
        case 42: return @"\\";
        case 43: return @",";
        case 44: return @"/";
        case 45: return @"n";
        case 46: return @"m";
        case 47: return @".";
        case 48: return @"TAB";
        case 49: return @"SPACE";
        case 50: return @"`";
        case 51: return @"DELETE";
        case 52: return @"ENTER";
        case 53: return @"ESCAPE";

            // some more missing codes abound, reserved I presume, but it would
            // have been helpful for Apple to have a document with them all listed

        case 65: return @".";

        case 67: return @"*";

        case 69: return @"+";

        case 71: return @"CLEAR";

        case 75: return @"/";
        case 76: return @"ENTER";   // numberpad on full kbd

        case 78: return @"-";

        case 81: return @"=";
        case 82: return @"0";
        case 83: return @"1";
        case 84: return @"2";
        case 85: return @"3";
        case 86: return @"4";
        case 87: return @"5";
        case 88: return @"6";
        case 89: return @"7";

        case 91: return @"8";
        case 92: return @"9";

        case 96: return @"F5";
        case 97: return @"F6";
        case 98: return @"F7";
        case 99: return @"F3";
        case 100: return @"F8";
        case 101: return @"F9";

        case 103: return @"F11";

        case 105: return @"F13";

        case 107: return @"F14";

        case 109: return @"F10";

        case 111: return @"F12";

        case 113: return @"F15";
        case 114: return @"HELP";
        case 115: return @"HOME";
        case 116: return @"PGUP";
        case 117: return @"DELETE";  // full keyboard right side numberpad
        case 118: return @"F4";
        case 119: return @"END";
        case 120: return @"F2";
        case 121: return @"PGDN";
        case 122: return @"F1";
        case 123: return @"LEFT";
        case 124: return @"RIGHT";
        case 125: return @"DOWN";
        case 126: return @"UP";

        default:

            return @"Unknown key";
            // Unknown key, bail and note that RUI needs improvement
            //fprintf(stderr, "%ld\tKey\t%c (DEBUG: %d)\n", currenttime, keyCode;
            //exit(EXIT_FAILURE;
    }
}

+ (CGKeyCode)keyCodeFormKeyString:(NSString *)keyString
{
    if ([keyString isEqualToString:@"a"]) return 0;
    if ([keyString isEqualToString:@"s"]) return 1;
    if ([keyString isEqualToString:@"d"]) return 2;
    if ([keyString isEqualToString:@"f"]) return 3;
    if ([keyString isEqualToString:@"h"]) return 4;
    if ([keyString isEqualToString:@"g"]) return 5;
    if ([keyString isEqualToString:@"z"]) return 6;
    if ([keyString isEqualToString:@"x"]) return 7;
    if ([keyString isEqualToString:@"c"]) return 8;
    if ([keyString isEqualToString:@"v"]) return 9;
    // what is 10?
    if ([keyString isEqualToString:@"b"]) return 11;
    if ([keyString isEqualToString:@"q"]) return 12;
    if ([keyString isEqualToString:@"w"]) return 13;
    if ([keyString isEqualToString:@"e"]) return 14;
    if ([keyString isEqualToString:@"r"]) return 15;
    if ([keyString isEqualToString:@"y"]) return 16;
    if ([keyString isEqualToString:@"t"]) return 17;
    if ([keyString isEqualToString:@"1"]) return 18;
    if ([keyString isEqualToString:@"2"]) return 19;
    if ([keyString isEqualToString:@"3"]) return 20;
    if ([keyString isEqualToString:@"4"]) return 21;
    if ([keyString isEqualToString:@"6"]) return 22;
    if ([keyString isEqualToString:@"5"]) return 23;
    if ([keyString isEqualToString:@"="]) return 24;
    if ([keyString isEqualToString:@"9"]) return 25;
    if ([keyString isEqualToString:@"7"]) return 26;
    if ([keyString isEqualToString:@"-"]) return 27;
    if ([keyString isEqualToString:@"8"]) return 28;
    if ([keyString isEqualToString:@"0"]) return 29;
    if ([keyString isEqualToString:@"]"]) return 30;
    if ([keyString isEqualToString:@"o"]) return 31;
    if ([keyString isEqualToString:@"u"]) return 32;
    if ([keyString isEqualToString:@"["]) return 33;
    if ([keyString isEqualToString:@"i"]) return 34;
    if ([keyString isEqualToString:@"p"]) return 35;
    if ([keyString isEqualToString:@"RETURN"]) return 36;
    if ([keyString isEqualToString:@"l"]) return 37;
    if ([keyString isEqualToString:@"j"]) return 38;
    if ([keyString isEqualToString:@"'"]) return 39;
    if ([keyString isEqualToString:@"k"]) return 40;
    if ([keyString isEqualToString:@";"]) return 41;
    if ([keyString isEqualToString:@"\\"]) return 42;
    if ([keyString isEqualToString:@","]) return 43;
    if ([keyString isEqualToString:@"/"]) return 44;
    if ([keyString isEqualToString:@"n"]) return 45;
    if ([keyString isEqualToString:@"m"]) return 46;
    if ([keyString isEqualToString:@"."]) return 47;
    if ([keyString isEqualToString:@"TAB"]) return 48;
    if ([keyString isEqualToString:@"SPACE"]) return 49;
    if ([keyString isEqualToString:@"`"]) return 50;
    if ([keyString isEqualToString:@"DELETE"]) return 51;
    if ([keyString isEqualToString:@"ENTER"]) return 52;
    if ([keyString isEqualToString:@"ESCAPE"]) return 53;

    // some more missing codes abound, reserved I presume, but it would
    // have been helpful for Apple to have a document with them all listed

    if ([keyString isEqualToString:@"."]) return 65;

    if ([keyString isEqualToString:@"*"]) return 67;

    if ([keyString isEqualToString:@"+"]) return 69;

    if ([keyString isEqualToString:@"CLEAR"]) return 71;

    if ([keyString isEqualToString:@"/"]) return 75;
    if ([keyString isEqualToString:@"ENTER"]) return 76;  // numberpad on full kbd

    if ([keyString isEqualToString:@"="]) return 78;

    if ([keyString isEqualToString:@"="]) return 81;
    if ([keyString isEqualToString:@"0"]) return 82;
    if ([keyString isEqualToString:@"1"]) return 83;
    if ([keyString isEqualToString:@"2"]) return 84;
    if ([keyString isEqualToString:@"3"]) return 85;
    if ([keyString isEqualToString:@"4"]) return 86;
    if ([keyString isEqualToString:@"5"]) return 87;
    if ([keyString isEqualToString:@"6"]) return 88;
    if ([keyString isEqualToString:@"7"]) return 89;

    if ([keyString isEqualToString:@"8"]) return 91;
    if ([keyString isEqualToString:@"9"]) return 92;

    if ([keyString isEqualToString:@"F5"]) return 96;
    if ([keyString isEqualToString:@"F6"]) return 97;
    if ([keyString isEqualToString:@"F7"]) return 98;
    if ([keyString isEqualToString:@"F3"]) return 99;
    if ([keyString isEqualToString:@"F8"]) return 100;
    if ([keyString isEqualToString:@"F9"]) return 101;

    if ([keyString isEqualToString:@"F11"]) return 103;

    if ([keyString isEqualToString:@"F13"]) return 105;

    if ([keyString isEqualToString:@"F14"]) return 107;

    if ([keyString isEqualToString:@"F10"]) return 109;

    if ([keyString isEqualToString:@"F12"]) return 111;

    if ([keyString isEqualToString:@"F15"]) return 113;
    if ([keyString isEqualToString:@"HELP"]) return 114;
    if ([keyString isEqualToString:@"HOME"]) return 115;
    if ([keyString isEqualToString:@"PGUP"]) return 116;
    if ([keyString isEqualToString:@"DELETE"]) return 117;
    if ([keyString isEqualToString:@"F4"]) return 118;
    if ([keyString isEqualToString:@"END"]) return 119;
    if ([keyString isEqualToString:@"F2"]) return 120;
    if ([keyString isEqualToString:@"PGDN"]) return 121;
    if ([keyString isEqualToString:@"F1"]) return 122;
    if ([keyString isEqualToString:@"LEFT"]) return 123;
    if ([keyString isEqualToString:@"RIGHT"]) return 124;
    if ([keyString isEqualToString:@"DOWN"]) return 125;
    if ([keyString isEqualToString:@"UP"]) return 126;

    return 0;
    //fprintf(stderr, "keyString %s Not Found. Aborting...\n", keyString);
    //exit(EXIT_FAILURE);
}

original code from here: http://ritter.ist.psu.edu/projects/RUI/macosx/rui.c

来自这里的原始代码：http：//ritter.ist.psu.edu/projects/RUI/macosx/rui.c

#3

Your own solution works fine under Qt too after a small patch (casting to CFDataRef):

在一个小补丁（转换为CFDataRef）之后，你自己的解决方案在Qt下运行正常：

Replacing

更换

CFDataRef layoutData = TISGetInputSourceProperty(currentKeyboard, kTISPropertyUnicodeKeyLayoutData);

with

同

CFDataRef layoutData = (CFDataRef)TISGetInputSourceProperty(currentKeyboard, kTISPropertyUnicodeKeyLayoutData);

avoids the error:

避免错误：

invalid conversion from 'void*' to 'const __CFData*'

从'void *'到'const __CFData *'的无效转换

#4

For those like me who searched for a more up-to-date version of what Michael proposed, here is what I ended up doing myself (for me it solved some segfault issue, probably because the garbage collector is doing its job with this version).

对于那些寻找迈克尔提出的最新版本的人来说，这就是我最终自己做的事情（对我而言，它解决了一些段错误问题，可能是因为垃圾收集器正在使用此版本） 。

The first function comes from Convert Virtual Key Code to unicode string.

第一个函数来自转换虚拟密钥代码到unicode字符串。

NSString* keyCodeToString(CGKeyCode keyCode)
{
  TISInputSourceRef currentKeyboard = TISCopyCurrentKeyboardInputSource();
  CFDataRef uchr =
    (CFDataRef)TISGetInputSourceProperty(currentKeyboard,
                                         kTISPropertyUnicodeKeyLayoutData);
  const UCKeyboardLayout *keyboardLayout =
    (const UCKeyboardLayout*)CFDataGetBytePtr(uchr);

  if(keyboardLayout)
  {
    UInt32 deadKeyState = 0;
    UniCharCount maxStringLength = 255;
    UniCharCount actualStringLength = 0;
    UniChar unicodeString[maxStringLength];

    OSStatus status = UCKeyTranslate(keyboardLayout,
                                     keyCode, kUCKeyActionDown, 0,
                                     LMGetKbdType(), 0,
                                     &deadKeyState,
                                     maxStringLength,
                                     &actualStringLength, unicodeString);

    if (actualStringLength == 0 && deadKeyState)
    {
      status = UCKeyTranslate(keyboardLayout,
                                       kVK_Space, kUCKeyActionDown, 0,
                                       LMGetKbdType(), 0,
                                       &deadKeyState,
                                       maxStringLength,
                                       &actualStringLength, unicodeString);
    }
    if(actualStringLength > 0 && status == noErr)
      return [[NSString stringWithCharacters:unicodeString
                        length:(NSUInteger)actualStringLength] lowercaseString];
  }

  return nil;
}

NSNumber* charToKeyCode(const char c)
{
  static NSMutableDictionary* dict = nil;

  if (dict == nil)
  {
    dict = [NSMutableDictionary dictionary];

    // For every keyCode
    size_t i;
    for (i = 0; i < 128; ++i)
    {
      NSString* str = keyCodeToString((CGKeyCode)i);
      if(str != nil && ![str isEqualToString:@""])
      {
        [dict setObject:[NSNumber numberWithInt:i] forKey:str];
      }
    }
  }

  NSString * keyChar = [NSString stringWithFormat:@"%c" , c];

  return [dict objectForKey:keyChar];
}

I used NSNumber to get a nullable object, the value returned by charToKeyCode(c) can then be tested against nil and then accessed with (CGKeyCode)[charToKeyCode(c) intValue].

我使用NSNumber来获取一个可以为空的对象，然后charToKeyCode（c）返回的值可以针对nil进行测试，然后使用（CGKeyCode）[charToKeyCode（c）intValue]进行访问。