如果项目中有评论或者信息恢复的地方，往往会用到emoji，有时候如后台不支持emoji，就会显示乱码错误，我们可以把emoji转成unicode编码或者utf8编码格式传给服务器。当然如果后台服务器接收的时候能做好判断识别最好，我们这边后台是支持的，我仅记录一下方法，以备不时之需。
先定义一个UITextView 并设置代理
设定一个宏定义，用来判断emoji
#define MULITTHREEBYTEUTF16TOUNICODE(x,y) (((((x ^ 0xD800) << 2) | ((y ^ 0xDC00) >> 8)) << 8) | ((y ^ 0xDC00) & 0xFF)) + 0x10000
下面写代理方法实现的内容
1 - (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text
2 {
3 NSString *hexstr = @"";
4
5 for (int i=0;i< [text length];i++)
6 {
7 hexstr = [hexstr stringByAppendingFormat:@"%@",[NSString stringWithFormat:@"0x%1X ",[text characterAtIndex:i]]];
8 }
9 NSLog(@"UTF16 [%@]",hexstr);
10
11 hexstr = @"";
12
13 long slen = strlen([text UTF8String]);
14
15 for (int i = 0; i < slen; i++)
16 {
17 //fffffff0 去除前面六个F & 0xFF
18 hexstr = [hexstr stringByAppendingFormat:@"%@",[NSString stringWithFormat:@"0x%X ",[text UTF8String][i] & 0xFF ]];
19 }
20 NSLog(@"UTF8 [%@]",hexstr);
21
22 hexstr = @"";
23
24 if ([text length] >= 2) {
25
26 for (int i = 0; i < [text length] / 2 && ([text length] % 2 == 0) ; i++)
27 {
28 // three bytes
29 if (([text characterAtIndex:i*2] & 0xFF00) == 0 ) {
30 hexstr = [hexstr stringByAppendingFormat:@"Ox%1X 0x%1X",[text characterAtIndex:i*2],[text characterAtIndex:i*2+1]];
31 }
32 else
33 {// four bytes
34 hexstr = [hexstr stringByAppendingFormat:@"U+%1X ",MULITTHREEBYTEUTF16TOUNICODE([text characterAtIndex:i*2],[text characterAtIndex:i*2+1])];
35 }
36
37 }
38 NSLog(@"(unicode) [%@]",hexstr);
39 }
40 else
41 {
42 NSLog(@"(unicode) U+%1X",[text characterAtIndex:0]);
43 }
44
45 return YES;
46 }
在输入的时候，会自动把输入内容转成相应的格式。
如果在有些地方不需要输入emoji表情，可以做相关限制。
我这边用到的是，如果用户输入emoji表情的时候，会给出提示
1 //是否含有表情
2 - (BOOL)stringContainsEmoji:(NSString *)string
3 {
4 __block BOOL returnValue = NO;
5
6 [string enumerateSubstringsInRange:NSMakeRange(0, [string length])
7 options:NSStringEnumerationByComposedCharacterSequences
8 usingBlock:^(NSString *substring, NSRange substringRange, NSRange enclosingRange, BOOL *stop) {
9 const unichar hs = [substring characterAtIndex:0];
10 if (0xd800 <= hs && hs <= 0xdbff) {
11 if (substring.length > 1) {
12 const unichar ls = [substring characterAtIndex:1];
13 const int uc = ((hs - 0xd800) * 0x400) + (ls - 0xdc00) + 0x10000;
14 if (0x1d000 <= uc && uc <= 0x1f77f) {
15 returnValue = YES;
16 }
17 }
18 } else if (substring.length > 1) {
19 const unichar ls = [substring characterAtIndex:1];
20 if (ls == 0x20e3) {
21 returnValue = YES;
22 }
23 } else {
24 if (0x2100 <= hs && hs <= 0x27ff) {
25 returnValue = YES;
26 } else if (0x2B05 <= hs && hs <= 0x2b07) {
27 returnValue = YES;
28 } else if (0x2934 <= hs && hs <= 0x2935) {
29 returnValue = YES;
30 } else if (0x3297 <= hs && hs <= 0x3299) {
31 returnValue = YES;
32 } else if (hs == 0xa9 || hs == 0xae || hs == 0x303d || hs == 0x3030 || hs == 0x2b55 || hs == 0x2b1c || hs == 0x2b1b || hs == 0x2b50) {
33 returnValue = YES;
34 }
35 }
36 }];
37
38 return returnValue;
39 }
通过调用该方法，如果返回的是YES则输入内容含有emoji，反之。