NSString剔除emoji表情

给NSString 写个分类

@implementation NSString(EmojiExtension)

- (NSString*)removeEmoji {

__block NSMutableString* temp = [NSMutableString    string];

[self enumerateSubstringsInRange: NSMakeRange(0,     [self length])     options:NSStringEnumerationByComposedCharacterSequences usingBlock:^(NSString *substring, NSRange substringRange,    NSRange enclosingRange, BOOL *stop){const unichar hs = [substring characterAtIndex: 0];

// surrogate pair

if (0xd800 <= hs && hs <= 0xdbff) {const unichar ls = [substring characterAtIndex: 1];
const int uc = ((hs - 0xd800) * 0x400) + (ls - 0xdc00) + 0x10000;
[temp appendString: (0x1d000 <= uc && uc <= 0x1f77f)? @"": substring]; // U+1D000-1F77F

// non surrogate

} else {
[temp appendString: (0x2100 <= hs && hs <= 0x26ff)? @"": substring]; // U+2100-26FF

}

}];

return temp;

}

@end

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