iOS从文件读取字符串，无分隔符分割成数组

iOS从文件读取中午使用UTF-8编码时，部分复杂的中文会占用4-6个字节。如果按1位来分割加入数组就会出现错误。如 𬺓 字，会占用两个长度。

    NSString *files  = [[NSBundle bundleWithPath:_bundlePath] pathForResource:@"cn_1.1" ofType:@"txt"];
    NSString *lines   = [[NSString stringWithContentsOfFile:files encoding:NSUTF8StringEncoding error:nil] stringByReplacingOccurrencesOfString:@"\n" withString:@""];
    NSMutableArray *characterArray = [NSMutableArray array];
    NSRange range = NSMakeRange(0, 1);
    for(int i = 0; i < lines.length; i += range.length){
        range.location = i;
        NSString *character = [lines substringWithRange:range];
        [characterArray addObject:character];
    }

77695B33-126B-4E32-B8EC-C33FCC3CB780.png

使用[str rangeOfComposedCharacterSequenceAtIndex:i]方法可以获得改文字的真实长度，用于分割可以得到正确的结果

    NSString *files  = [[NSBundle bundleWithPath:_bundlePath] pathForResource:@"cn_1.1" ofType:@"txt"];
    NSString *lines   = [[NSString stringWithContentsOfFile:files encoding:NSUTF8StringEncoding error:nil] stringByReplacingOccurrencesOfString:@"\n" withString:@""];
    NSMutableArray *characterArray = [NSMutableArray array];
    NSRange range = NSMakeRange(0, 1);
    for(int i = 0; i < lines.length; i += range.length){
        range = [lines rangeOfComposedCharacterSequenceAtIndex:i];
        NSString *character = [lines substringWithRange:range];
        [characterArray addObject:character];
    }