科普。
Emoji來源就不多說了，只要知道在某個版本的Unicode編碼中加入了Emoji慕购，并且不是放一塊的，也就說在Unicode編碼中播急，Emoji的地址沒有規(guī)律可尋脓钾，那只能去硬匹配，可Emoji數(shù)量幾百上千桩警，這一個個去匹配實在太蠢了，咱得縮小匹配范圍昌妹。相信現(xiàn)在大家都用的UTF8編碼捶枢，這是一種變長編碼握截，提到變長，那肯定會有一個描述頭烂叔，幾個內(nèi)容體谨胞，UTF8是一樣的。
在一個字節(jié)中蒜鸡，如果第一個bit位是0胯努，那么代表當前為單字節(jié)字符，0之后的7位bit為數(shù)據(jù)部分逢防，代表在Unicode中的序號對應(yīng)的叶沛，如果第一位是1開頭，代表是多字節(jié)字符忘朝，如果第二位是0灰署，代表這個字節(jié)是多字節(jié)字符的數(shù)據(jù)字節(jié)，跟在頭字節(jié)后面局嘁；如果前面有多個1溉箕，則幾個1代表該字符有幾個字節(jié)（包含當前字節(jié)），例如：
110xxxxx // 代表有兩個字節(jié)悦昵，后面一定跟著一個10開頭的數(shù)據(jù)字節(jié)
110xxxxx 10xxxxxx
1110xxxx // 代表有三個字節(jié)肴茄，后面跟著兩個10開頭的數(shù)據(jù)字節(jié)
1110xxxx 10xxxxxx 10xxxxxx
推理可知，Utf8中一個字符最長7個字節(jié)但指，其中數(shù)據(jù)位6個字節(jié)独郎，其中Emoji在Unicode中分布在2、3枚赡、4氓癌、4+長度的地址中，其中長度為2的Emoji大部分是文字字符贫橙，這些我們可以放行贪婉，4、4+的Emoji可全部過濾卢肃，而我們可見文字基本都分部在3字節(jié)地址中疲迂，這里重點需要過濾3字節(jié)的Emoji（3字節(jié)的Emoji已經(jīng)可以入庫了，但為了統(tǒng)一體驗莫湘，還是需要過濾掉）尤蒿，幸運的是3字節(jié)的Emoji不是很多，硬匹配也算說得過去幅垮。
實現(xiàn)腰池。
1.根據(jù)從Unicode官網(wǎng)找到的資料，匹配三字節(jié)Unicode
- (BOOL) emojiInUnicode:(short)code
{
if (code == 0x0023
|| code == 0x002A
|| (code >= 0x0030 && code <= 0x0039)
|| code == 0x00A9
|| code == 0x00AE
|| code == 0x203C
|| code == 0x2049
|| code == 0x2122
|| code == 0x2139
|| (code >= 0x2194 && code <= 0x2199)
|| code == 0x21A9 || code == 0x21AA
|| code == 0x231A || code == 0x231B
|| code == 0x2328
|| code == 0x23CF
|| (code >= 0x23E9 && code <= 0x23F3)
|| (code >= 0x23F8 && code <= 0x23FA)
|| code == 0x24C2
|| code == 0x25AA || code == 0x25AB
|| code == 0x25B6
|| code == 0x25C0
|| (code >= 0x25FB && code <= 0x25FE)
|| (code >= 0x2600 && code <= 0x2604)
|| code == 0x260E
|| code == 0x2611
|| code == 0x2614 || code == 0x2615
|| code == 0x2618
|| code == 0x261D
|| code == 0x2620
|| code == 0x2622 || code == 0x2623
|| code == 0x2626
|| code == 0x262A
|| code == 0x262E || code == 0x262F
|| (code >= 0x2638 && code <= 0x263A)
|| (code >= 0x2648 && code <= 0x2653)
|| code == 0x2660
|| code == 0x2663
|| code == 0x2665 || code == 0x2666
|| code == 0x2668
|| code == 0x267B
|| code == 0x267F
|| (code >= 0x2692 && code <= 0x2694)
|| code == 0x2696 || code == 0x2697
|| code == 0x2699
|| code == 0x269B || code == 0x269C
|| code == 0x26A0 || code == 0x26A1
|| code == 0x26AA || code == 0x26AB
|| code == 0x26B0 || code == 0x26B1
|| code == 0x26BD || code == 0x26BE
|| code == 0x26C4 || code == 0x26C5
|| code == 0x26C8
|| code == 0x26CE
|| code == 0x26CF
|| code == 0x26D1
|| code == 0x26D3 || code == 0x26D4
|| code == 0x26E9 || code == 0x26EA
|| (code >= 0x26F0 && code <= 0x26F5)
|| (code >= 0x26F7 && code <= 0x26FA)
|| code == 0x26FD
|| code == 0x2702
|| code == 0x2705
|| (code >= 0x2708 && code <= 0x270D)
|| code == 0x270F
|| code == 0x2712
|| code == 0x2714
|| code == 0x2716
|| code == 0x271D
|| code == 0x2721
|| code == 0x2728
|| code == 0x2733 || code == 0x2734
|| code == 0x2744
|| code == 0x2747
|| code == 0x274C
|| code == 0x274E
|| (code >= 0x2753 && code <= 0x2755)
|| code == 0x2757
|| code == 0x2763 || code == 0x2764
|| (code >= 0x2795 && code <= 0x2797)
|| code == 0x27A1
|| code == 0x27B0
|| code == 0x27BF
|| code == 0x2934 || code == 0x2935
|| (code >= 0x2B05 && code <= 0x2B07)
|| code == 0x2B1B || code == 0x2B1C
|| code == 0x2B50
|| code == 0x2B55
|| code == 0x3030
|| code == 0x303D
|| code == 0x3297
|| code == 0x3299
// 第二段
|| code == 0x23F0) {
return YES;
}
return NO;
}
2.另外還有很古老的一套Emoji，采用Unicode私有區(qū)域示弓，現(xiàn)在基本沒用了讳侨，不過還是過濾下
- (BOOL) emojiInSoftBankUnicode:(short)code
{
return ((code >> 8) >= 0xE0 && (code >> 8) <= 0xE5 && (Byte)(code & 0xFF) < 0x60);
}
3.對輸入string的過濾，需要過濾掉字節(jié)長度為非3的字符奏属，然后校驗3字節(jié)的unicode編碼
- (BOOL) containEmoji
{
NSUInteger len = [self lengthOfBytesUsingEncoding:NSUTF8StringEncoding];
if (len < 3) {// 大于2個字符需要驗證Emoji(有些Emoji僅三個字符)
return NO;
}// 僅考慮字節(jié)長度為3的字符,大于此范圍的全部做Emoji處理
NSData *data = [self dataUsingEncoding:NSUTF8StringEncoding];Byte *bts = (Byte *)[data bytes];
Byte bt;
short v;
for (NSUInteger i = 0; i < len; i++) {
bt = bts[i];
if ((bt | 0x7F) == 0x7F) {// 0xxxxxxxASIIC編碼
continue;
}
if ((bt | 0x1F) == 0xDF) {// 110xxxxx兩個字節(jié)的字符
i += 1;
continue;
}
if ((bt | 0x0F) == 0xEF) {// 1110xxxx三個字節(jié)的字符(重點過濾項目)
// 計算Unicode下標
v = bt & 0x0F;
v = v << 6;
v |= bts[i + 1] & 0x3F;
v = v << 6;
v |= bts[i + 2] & 0x3F;
// NSLog(@"%02X%02X", (Byte)(v >> 8), (Byte)(v & 0xFF));
if ([self emojiInSoftBankUnicode:v] || [self emojiInUnicode:v]) {
return YES;
}
i += 2;
continue;
}
if ((bt | 0x3F) == 0xBF) {// 10xxxxxx10開頭,為數(shù)據(jù)字節(jié),直接過濾
continue;
}
return YES; // 不是以上情況的字符全部超過三個字節(jié),做Emoji處理
}return NO;
}
感謝來自oscine的作者xoHome的文章跨跨。
