NSString 到 unicode asic utf-8 gbk

 NSString *test = @"123abc王国"; 
 
 //NSLog(@"abc:%@",result);
 //NSData *data = [test dataUsingEncoding:NSUnicodeStringEncoding]; //unicode
 //NSData *data = [test dataUsingEncoding:NSASCIIStringEncoding];   //asic
 //NSData *data = [test dataUsingEncoding:NSUTF8StringEncoding];    //utf-8
 
 NSStringEncoding enc = CFStringConvertEncodingToNSStringEncoding(kCFStringEncodingGB_18030_2000);
 NSData *data = [test dataUsingEncoding:enc];
 
 
// NSStringEncoding enc = CFStringConvertEncodingToNSStringEncoding(kCFStringEncodingGB_18030_2000)
 
 NSString *result = [[NSString alloc] initWithData:data encoding:enc];    //转换成NSString unicode 格式
 
 
 NSLog(@"data:%@",data);
 
 NSLog(@"result:%@",result);