This is going to be a work in process. 
Props go to Zebra developers and their ISV team for helping!

#import #import "ZebraPrinterConnection.h" #import "MfiBtPrinterConnection.h" #import "TcpPrinterConnection.h" #import "ZebraPrinter.h" #import "ZebraPrinterFactory.h" #import "ToolsUtil.h"  //object to JSON string NSString* objectToJson(NSObject* obj) {   if( NSClassFromString( @"NSJSONSerialization" ) )   {         if( [NSJSONSerialization isValidJSONObject:obj] )   {   NSError *error = nil;   NSData *jsonData = [NSJSONSerialization dataWithJSONObject:obj options:0 error:&error];                if( jsonData && !error )   return [[[NSString alloc] initWithData:jsonData encoding:NSUTF8StringEncoding] autorelease];   else   NSLog( @"jsonData was null, error: %@", [error localizedDescription] );         }   }       return @"{}"; }  //convert UTF8 NSString to a managed string char* cStringCopy(const char* string) {     if(string == NULL)         return NULL;          char* res = (char*)malloc(strlen(string) + 1);     strcpy(res, string);          return res; }  //convert managed string to NSSTring static NSString* CreateNSString(const char* string) {     if(string != NULL)         return [NSString stringWithUTF8String:string];     else         return [NSString stringWithUTF8String:""];      }  /*void runOnMainQueueWithoutDeadlocking(void (^block)(void)) {     if([NSThread isMainThread])     {         block();     }     else     {         dispatch_sync(dispatch_get_main_queue(),block);     } }*/  id getBluetoothPrinterConnection(NSString* serialNumber) {     return [[MfiBtPrinterConnection alloc] initWithSerialNumber:serialNumber]; }  id getTcpPrinterConnection(NSString* address, NSInteger port) {     return [[TcpPrinterConnection alloc] initWithAddress:address andWithPort:port]; }  extern "C" {          int GetConnectedPrinterCount()     {         int count = 0;                  EAAccessoryManager *sam = [EAAccessoryManager sharedAccessoryManager];         NSArray *connectedAccessories = [sam connectedAccessories];                  for (EAAccessory *accessory in connectedAccessories)         {             if([accessory.protocolStrings indexOfObject:@"com.zebra.rawport"] != NSNotFound)             {                 count++;             }         }                  return count;              }          const char* GetConnectedPrinterSerialNumbers()     {         NSMutableArray *snArray = [[NSMutableArray alloc] init];                  EAAccessoryManager *sam = [EAAccessoryManager sharedAccessoryManager];         NSArray *connectedAccessories = [sam connectedAccessories];                  for (EAAccessory *accessory in connectedAccessories)         {             if([accessory.protocolStrings indexOfObject:@"com.zebra.rawport"] != NSNotFound)             {                 [snArray addObject:[NSString stringWithString:accessory.serialNumber]];             }         }                  NSString *json = objectToJson(snArray);                  return cStringCopy(json.UTF8String);     }          const char* GetFirstConnectedPrinterSerialNumber()     {         NSString *serialNumber = @"";                  EAAccessoryManager *sam = [EAAccessoryManager sharedAccessoryManager];         NSArray *connectedAccessories = [sam connectedAccessories];                  for (EAAccessory *accessory in connectedAccessories)         {             if([accessory.protocolStrings indexOfObject:@"com.zebra.rawport"] != NSNotFound)             {                 serialNumber = accessory.serialNumber;                 break;             }         }                  return cStringCopy([serialNumber UTF8String]);     }          /*     //BROKEN     bool __SendZpl(const char* serialNumber, const char* zpl)     {         __block bool success = NO;                  dispatch_semaphore_t sema = dispatch_semaphore_create(0);                  dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{             @autoreleasepool {                 id thePrinterConn = getBluetoothPrinterConnection(CreateNSString(serialNumber));                 success = [thePrinterConn open];                                  NSError *error = nil;                 success = success && [thePrinterConn write:[CreateNSString(zpl) dataUsingEncoding:NSUTF8StringEncoding] error:&error];                 success = success && !error;                                  [thePrinterConn close];                 [thePrinterConn release];             }                          dispatch_semaphore_signal(sema);         });                  dispatch_semaphore_wait(sema, DISPATCH_TIME_FOREVER);                  return success;     }*/          bool SendZpl(const char* serialNumber, const char* zpl)     {         __block bool success = NO;         __block NSString *zplString = CreateNSString(zpl);         __block NSString *serialNumberString = CreateNSString(serialNumber);                  dispatch_group_t group = dispatch_group_create();                  dispatch_group_async(group, dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{             @autoreleasepool {                 id thePrinterConn = getBluetoothPrinterConnection(serialNumberString);                 success = [thePrinterConn open];                                  NSError *error = nil;                 NSLog(@"Start Printing");                                  success = success && [thePrinterConn write:[zplString dataUsingEncoding:NSUTF8StringEncoding] error:&error];                 NSLog(@"Done Printing");                 success = success && !error;                                  [thePrinterConn close];                 [thePrinterConn release];             }                      });                  dispatch_group_notify(group,dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0), ^ {         });                  dispatch_release(group);                  return success;     }          //TODO     bool PrintStoredFormat(const char* serialNumber, const char* formatPath)     {         __block bool success = NO;                  dispatch_semaphore_t sema = dispatch_semaphore_create(0);                  dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{             @autoreleasepool {                 id thePrinterConn = getBluetoothPrinterConnection(CreateNSString(serialNumber));                 success = [thePrinterConn open];                                  if(success)                 {                     NSError *error = nil;                                          id printer = [ZebraPrinterFactory getInstance:thePrinterConn error:&error];                                          if(printer && !error)                     {                         id formatUtil = [printer getFormatUtil];                                                  success = success && [formatUtil printStoredFormat:CreateNSString(formatPath) withDictionary:nil error:&error];                         success = success && !error;                     }                 }                                  [thePrinterConn close];                 [thePrinterConn release];             }                          dispatch_semaphore_signal(sema);         });                  dispatch_semaphore_wait(sema, DISPATCH_TIME_FOREVER);                  return success;     }          //TODO     bool PrintConfigurationLabel(const char* serialNumber)     {         bool success = NO;                  id thePrinterConn = getBluetoothPrinterConnection(CreateNSString(serialNumber));         success = [thePrinterConn open];         //NSLog(@"printer connection open: %d", success);                  if(success)         {             NSError *error = nil;                          id printer = [ZebraPrinterFactory getInstance:thePrinterConn error:&error];                          if(printer!=nil && error == nil)             {                 id toolsUtil = [printer getToolsUtil];                                  success = success && [toolsUtil printConfigurationLabel:&error];                 success = success && !error;             }         }                  [thePrinterConn close];         [thePrinterConn release];                  return success;     }      }   
using UnityEngine; using System.Collections; using System.Runtime.InteropServices; using System;  public class ZebraAPI  {     [DllImport("__Internal")]     public static extern int GetConnectedPrinterCount();          [DllImport("__Internal")]     private static extern IntPtr getConnectedPrinterSerialNumbers();          public static string GetConnectedPrinterSerialNumbers()     {         IntPtr ptr = getConnectedPrinterSerialNumbers();         return  Marshal.PtrToStringAnsi(ptr);     }          [DllImport("__Internal")]     private static extern IntPtr getFirstConnectedPrinterSerialNumber();          public static string GetFirstConnectedPrinterSerialNumbers()     {         IntPtr ptr = getFirstConnectedPrinterSerialNumber();         return  Marshal.PtrToStringAnsi(ptr);     }          [DllImport("__Internal")]     public static extern bool SendZpl(string serialNumber, string zpl);          [DllImport("__Internal")]     public static extern bool PrintStoredFormat(string serialNumber, string formatPath);          [DllImport("__Internal")]     public static extern bool PrintConfigurationLabel(string serialNumber); }