https://www.twblogs.net/a/5b7e01e22b7177683854b7b8/zh-cn
搜索 CFStringConvertEncodingToNSStringEncoding
原来是 kCFStringEncodingDOSLatinUS
改成下面的：
NSStringEncoding enc = CFStringConvertEncodingToNSStringEncoding(kCFStringEncodingGB_18030_2000);
NSString *strPath = [NSString stringWithCString:filename encoding:enc];