Hi. I have a problem with printing label. I have a WebView app with button (Print), when i push the button (Print), sometimes label is not printed without any errors. I tried to change timeout but this didn’t help.
We have 5 printers QLn 320 with last firmware V68.19.15Z and many iPad with iOS 9.2, 9.1, 8.1. This problem has long. Label 43x25мм and print 5 lines. 1-2Lines - Name, 3Lines - Size, 4Lines - order,date,article, 5Lines - barcode.
I use Zebra SDK and print code is:
 
-(
-(void)printWithGCDWithParameters:(NSDictionary *)parameters {
    //Dispatch this task to the default queue
    buttonhome.enabled = NO;
    buttonSettings.enabled = NO;
    viewPrinting.hidden = NO;
    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^ {
        // Instantiate connection to Zebra Bluetooth accessory
        NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
        NSString *serialNumber = [defaults valueForKey:@"selectedPrinterSN"];
        id thePrinterConn = [[MfiBtPrinterConnection alloc] initWithSerialNumber:serialNumber];
        NSInteger timeout = [defaults integerForKey:@"OZTimeout"];
        if (timeout 30) {
            timeout = 30;
        }
        else if (timeout > 300) {
            timeout = 300;
        }
        [((MfiBtPrinterConnection*)thePrinterConn) setTimeToWaitAfterWriteInMilliseconds:timeout];
        [((MfiBtPrinterConnection*)thePrinterConn) setTimeToWaitAfterReadInMilliseconds:timeout];
      
        BOOL success = [thePrinterConn open];
      
        NSString *size = [parameters valueForKey:@"size"];
        size = [size stringByReplacingOccurrencesOfString:@"" withString:@""];
        size = [size stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
        NSInteger symbolCount = 33;
        NSString *name = [parameters valueForKey:@"title"];
        NSString *name2 = @"";
        if (name.length > symbolCount) {
            name2 = [name substringFromIndex:symbolCount];
            name = [name substringToIndex:symbolCount];
          }
        NSString *zplData = [NSString stringWithFormat:
                              @"^XA^LH25,23^POI^CFT,20,20^CI28^FT5,5^FH^A@N,20,20,E:TT0003M_.TTF^FD%@^FS^FT5,25^FH^A@N,20,20,E:TT0003M_.TTF^FD%@^FS^FT5,45^FH^A@N,20,20,E:TT0003M_.TTF^FD%@%@^FS^FT5,65^FH^A@N,20,20,E:TT0003M_.TTF^FDЗаказ № %@   %@   %@^FS^FO30,80^BY2 ^BCN,50,Y,N,N,A^FD%@^FS^XZ",
                             name, name2, size.length > 0 ? @"Размер: " : @"", size, [parameters valueForKey:@"number"],[parameters valueForKey:@"nowDate"], [parameters valueForKey:@"artPostavshik"], [parameters valueForKey:@"barnumber"]];
      
        NSError *error = nil;
 
        NSMutableData *data = [[zplData dataUsingEncoding:NSUTF8StringEncoding] mutableCopy];
      
        long blockSize = 1024;
        long totalSize = data.length;
        long bytesRemaining = totalSize;
        while (bytesRemaining > 0) {
            long bytesToSend = MIN(blockSize, bytesRemaining);
            NSRange range = NSMakeRange(0, bytesToSend);
          
            NSData *partialLabel = [data subdataWithRange:range];
            [thePrinterConn write:partialLabel error:&error];
          
            bytesRemaining -= bytesToSend;
          
            [data replaceBytesInRange:range withBytes:NULL length:0];
            if (error) {
                break;
            }
        }
      
        [thePrinterConn close];