如何将ASCII字符转换为CGKeyCode?

时间:2009-12-17 01:00:47

标签: c macos quartz-graphics keypress keycode

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位置相关联的CGKeyCode。例如,给定“b”,如果使用美国QWERTY则返回kVK_ANSI_B,如果使用Dvorak则返回kVK_ANSI_N

为此,Win32 API具有函数VkKeyScan(); X11具有函数XStringToKeySym()。 CG API中有这样的功能吗?

我需要这个才能将参数传递给CGEventCreateKeyboardEvent()。我尝试使用CGEventKeyboardSetUnicodeString(),但显然是does not support修饰符标记(我需要)。

我已经广泛搜索过这个但是找不到合适的答案。目前我正在使用以下代码(found online),它有效,但不是很优雅(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;
}

是否有。)(最好)我忽略的标准功能,或者b。)(几乎可以肯定)更优雅的方式写我自己的?

5 个答案:

答案 0 :(得分:28)

这是我最终使用的。更干净。

#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;
}

答案 1 :(得分:7)

+ (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);
}

原始代码来自: http://ritter.ist.psu.edu/projects/RUI/macosx/rui.c

答案 2 :(得分:4)

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:

更换

CFDataRef layoutData = TISGetInputSourceProperty(currentKeyboard, kTISPropertyUnicodeKeyLayoutData);

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

避免错误:

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

答案 3 :(得分:3)

对于像我一样搜索迈克尔提出的更多最新版本的人来说,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)。

第一个功能来自Convert Virtual Key Code to unicode string

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];
}

我使用NSNumber获取可以为空的对象,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。

答案 4 :(得分:1)

我知道这个问题已经有很长的历史了,但是如果有人仍然感兴趣,我会模拟不依赖碳程序的版本。实际上,它走得更远,因为它将把可以键入的任何字符映射回其虚拟键代码和修饰符组合。

- (NSDictionary *)characterToKeyCode:(NSString *)character {
    static NSDictionary * keyMapDict;

    if (keyMapDict == nil) {
        keyMapDict = [self makeKeyMap];
    }

    /*
     The returned dictionary contains entries for the virtual key code and boolen flags
     for modifier keys used for the character.
     */
    return [keyMapDict objectForKey:character];
}

- (NSDictionary *)makeKeyMap {
    CGKeyCode keyCode;
    CGEventRef coreEvent;
    NSEvent * keyEvent;
    NSUInteger modifiers = 0;
    NSMutableDictionary * subDict, * keyMapDict;
    NSString *character;
    BOOL modKeyIsUsed;

    static NSDictionary * modFlagDict;
    static NSArray * modFlags;

    // create dictionary of modifier names and keys. I've used all the modifiers, but I doubt theya re all needed.
    if (modFlagDict == nil) {
        modFlagDict = @{@"option":@(NSEventModifierFlagOption),
                        @"shift": @(NSEventModifierFlagShift),
                        @"function":@(NSEventModifierFlagFunction),
                        @"control": @(NSEventModifierFlagControl),
                        @"command":@(NSEventModifierFlagCommand)};
        modFlags = [modFlagDict allValues];
    }
    keyMapDict = [NSMutableDictionary dictionary];

    // run through 128 base key codes to see what they produce
    for (keyCode = 0; keyCode < 128; ++keyCode) {
        // create dummy NSEvent from a CGEvent for a keypress
        coreEvent = CGEventCreateKeyboardEvent(NULL, keyCode, true);
        keyEvent = [NSEvent eventWithCGEvent:coreEvent];
        CFRelease(coreEvent);

        if (keyEvent.type == NSEventTypeKeyDown) {
            // this do/while loop through every permutation of modifier keys for a given key code
            do {
                subDict = [NSMutableDictionary dictionary];
                // cerate dictionary containing current modifier keys and virtual key code
                for (NSString * key in modFlagDict) {
                    modKeyIsUsed = ([(NSNumber *)[modFlagDict objectForKey:key] unsignedLongValue] & modifiers) ? YES : NO;
                    [subDict setObject:[NSNumber numberWithBool:modKeyIsUsed]
                                forKey:key];
                }
                [subDict setObject:[NSNumber numberWithUnsignedLong:(unsigned long)keyCode]
                            forKey:@"virtKeyCode"];

                // manipulate the NSEvent to get character produce by virtual key code and modifiers
                if (modifiers == 0) {
                    character = [keyEvent characters];
                } else {
                    character = [keyEvent charactersByApplyingModifiers:modifiers];
                }

                // add sub-dictionary to main dictionary using character as key
                if (![keyMapDict objectForKey:character]) {
                    [keyMapDict setObject:[NSDictionary dictionaryWithDictionary:subDict]
                                forKey:character];
                }

                // permutate the modifiers
                modifiers = [self permutatateMods:modFlags];
            } while (modifiers != 0);
        }
    }

    return [NSDictionary dictionaryWithDictionary:keyMapDict];
}

- (NSUInteger)permutatateMods:(NSArray *) modFlags {
    static NSMutableIndexSet * idxSet;
    NSArray * modArray;
    NSEnumerator * e;
    NSNumber * modObj;
    NSUInteger modifiers = 0, idx = 0;

    if (idxSet == nil) {
        idxSet = [NSMutableIndexSet indexSet];
    }

    /*
     Starting at 0, if the index exists, remove it and move up; if the index doesn't exist, add it. Will
     cycle through a standard binary progression. Indexes are then applied to the passed array, and the
     selected elements are 'OR'ed together
     */
    BOOL doneFlag = NO;
    while (!doneFlag) {
        if ([idxSet containsIndex:idx]) {
            [idxSet removeIndex:idx++];
            continue;
        }
        if (idx < [modFlags count]) {
            [idxSet addIndex:idx];
        } else {
            [idxSet removeAllIndexes];
        }
        doneFlag = YES;
    }

    modArray = [modFlags objectsAtIndexes:idxSet];
    e = [modArray objectEnumerator];
    while (modObj = [e nextObject]) {
        modifiers |= [modObj unsignedIntegerValue];
    }

    return modifiers;
}

例如,如果使用以下命令调用

NSDictionary * d = [self characterToKeyCode:@"π"];

它将返回一个字典,内容为:

Dictionary: {
    command = 0;
    control = 0;
    function = 0;
    option = 1;
    shift = 0;
    virtKeyCode = 35;
}

哪个说'pi'符号是由虚拟键代码35按下并按下选项键(在标准的美国键盘上为⌥P)产生的。