I am currently trying to communicate with a Zebra printer via a react-native application, on mobile I am trying to send my ZPL code (instructions for the printer to print the content i want) from my application to the printer via PrintConnect, Zebra also provides a pdf file guiding people on how to communicate to the app via intents available here however the examples dislpayed on the guide are using a different language.
My question then is how would i go about replicating this (Page 96, Passthrough Intent example) :
Intent intent = new Intent();
intent.setComponent(new ComponentName("com.zebra.printconnect",
"com.zebra.printconnect.print.PassthroughService"));
intent.putExtra("com.zebra.printconnect.PrintService.PASSTHROUGH_DATA", passthroughBytes);
intent.putExtra("com.zebra.printconnect.PrintService.RESULT_RECEIVER", buildIPCSafeReceiver(new
ResultReceiver(null) {
#Override
protected void onReceiveResult(int resultCode, Bundle resultData) {
if (resultCode == 0) { // Result code 0 indicates success
// Handle successful print
} else {
// Handle unsuccessful print
// Error message (null on successful print)
String errorMessage = resultData.getString("com.zebra.printconnect.PrintService.ERROR_MESSAGE");
}
}
}));
Into something acceptable by the react-native-send-intent package such as this:
SendIntentAndroid.openApp("com.mycorp.myapp", {
"com.mycorp.myapp.reason": "just because",
"com.mycorp.myapp.data": "must be a string",
}).then(wasOpened => {});
Thank you for the time you took to read my question.
Related
I am running the flutter platform channel "Eventchannel" with windows platform
I know this not mention in official platform channel document
but I found some example that work with windows and I test it.
Now, I can transfer the single data from below code:
void initEventChannel(flutter::FlutterEngine* flutter_instance) {
const static std::string event_channel_name("getFromWinsBrowsingDevice");
const flutter::StandardMethodCodec& codec = flutter::StandardMethodCodec::GetInstance();
flutter::EventChannel event_channel_name_(flutter_instance->messenger(), event_channel_name, &codec);
event_channel_name_.SetStreamHandler(
std::make_unique<flutter::StreamHandlerFunctions<flutter::EncodableValue>>(on_listen, on_cancel));
}
std::unique_ptr<flutter::StreamHandlerError<flutter::EncodableValue>> on_listen(
const flutter::EncodableValue* agruments,
std::unique_ptr<flutter::EventSink<flutter::EncodableValue>>&& events) {
std::thread BrowsingThread(sentBrowsingEvent, std::move(events));
BrowsingThread.detach();
return NULL;
}
void sentBrowsingEvent(std::unique_ptr<flutter::EventSink<flutter::EncodableValue>>&& events) {
//Browsing_Check_routine, &browsing_test
//creat MAP in Browsing_Check_routine to feedback the event to UI
while (1) {
Browsing_Check_routine()
events.get()->Success(flutter::EncodableValue(BrowsingDeviceMap)); // This will fail while send all MAP data
}
std::this_thread::sleep_for(std::chrono::seconds(1));
#endif
}
}
I want to receive some help, how should I fix this error to pass the MAP data to flutter side?
events.get()->Success(flutter::EncodableValue(BrowsingDeviceMap)); //
This will fail while send all MAP data
Thank you!
Edit:
I realize my map is c++ type, if I want to pass the map with the EncodableValue, the variable must declare in EncodableMap type.
I am currently trying to implement the Java web service(Rest API) where the endpoint creates the device in the IoTHub and updates the device twin.
There are two methods available in the azure-iot sdk. One is
addDevice(deviceId, authenticationtype)
and another is to
addDeviceAsync(deviceId, authenticationtype)
I just wanted to figure out which one should I use in the web service(as a best practice). I am not very strong in MultiThreading/Concurrency so was wondering to receive people's expertise on this. Any suggestion/Link related to this is much appreciated
Thanks.
The Async version of AddDevice is basically the same. If you use AddDeviceAsync then a thread is created to run the AddDevice call so you are not blocked on it.
Check the code#L269 of RegistryManager doing exactly that: https://github.com/Azure/azure-iot-sdk-java/blob/master/service/iot-service-client/src/main/java/com/microsoft/azure/sdk/iot/service/RegistryManager.java#L269
public CompletableFuture<Device> addDeviceAsync(Device device) throws IOException, IotHubException
{
if (device == null)
{
throw new IllegalArgumentException("device cannot be null");
}
final CompletableFuture<Device> future = new CompletableFuture<>();
executor.submit(() ->
{
try
{
Device responseDevice = addDevice(device);
future.complete(responseDevice);
}
catch (IOException | IotHubException e)
{
future.completeExceptionally(e);
}
});
return future;
}
You can as well build your own async wrapper and call AddDevice() from there.
I have developed an Android App which runs on both a smartphone and a smartwatch in parallel. On both devices, (let's say) it reads certain sensor data, processes that data (calculate its mean), and then store that results. The watch sends this result to the phone so all storing takes place on the phone. I used buffer writer to write a number into a text file every 5 seconds.
Now after every 320 data items exchanges from watch to the phone, my app on the phone gets killed and I get "the name of the app" is unfortunately stopped as a message. I can't figure it what why they stop exactly after this time? The app running on the watch continues to work fine. However, I cannot store its data because it cannot communicate to the phone version so I get this message "the app is unfortunately stopped as a message" every time the watch sends a number to phone for storing. The app has one activity which has a service (foreground).
Could it be that there is a limit on the amount of data being shared?
The code on watch:
// Create a data map and put data in it
private void increaseCounter() {
PutDataMapRequest putDataMapReq = PutDataMapRequest.create("/count");
putDataMapReq.getDataMap().putInt(COUNT_KEY, count++); // I add current time here as well
PutDataRequest putDataReq = putDataMapReq.asPutDataRequest();
PendingResult<DataApi.DataItemResult> pendingResult =
Wearable.DataApi.putDataItem(mGoogleApiClient, putDataReq);
}
Code on phone (possible problematic area):
#Override
public void onDataChanged(DataEventBuffer dataEvents) {
for (DataEvent event : dataEvents) {
if (event.getType() == DataEvent.TYPE_CHANGED) {
// DataItem changed
DataItem item = event.getDataItem();
if (item.getUri().getPath().compareTo("/count") == 0) {
DataMap dataMap = DataMapItem.fromDataItem(item).getDataMap();
updateCount(dataMap.getInt(COUNT_KEY));
}
} else if (event.getType() == DataEvent.TYPE_DELETED) {
// DataItem deleted
}
}
}
You have to use Service with StartForeground notification to be sure app is always working.
and try to use START_STICKY flag while staring.
UPDATE
You have to dealloc memory of dataevent:
#Override
public void onDataChanged(DataEventBuffer dataEvents) {
try{
for(DataEvent dataEvent: dataEvents){
if(dataEvent.getType() != DataEvent.TYPE_CHANGED){
continue;
}
////... code
dataEvents.release();
}catch (Exception e){
Log.v("SunshineWatchFace",e.getMessage());
}
}
I would like to print a receipt on an Epson thermal receipt printer using ESC/POS.
The printer is connected by USB and there is a printer driver installed. But I do not want to print a generated raster image. Instead I want to send the raw ESC/POS commands to the printer.
ESC/POS is basically plain text with some escaped commands that allow some additional formatting, cut the paper and even open a cash drawer that is connected to the printer. I've already created a Windows version of my application in C# and already know how to format the data that has to be send to the printer. For all intents and purposes of this question, assume that I have a buffer with valid ESC/POS commands that need to be send to the printer.
C# does not allow me to open a printer directly and write raw data to it, so I basically P/Invoke some functions from the Win32 API.
The code looks like this:
public Boolean Print(string printerName, byte[] document)
{
try
{
NativeMethods.DOC_INFO_1 documentInfo;
IntPtr printerHandle;
documentInfo = new NativeMethods.DOC_INFO_1();
documentInfo.pDataType = "RAW";
documentInfo.pDocName = "POS receipt";
printerHandle = new IntPtr(0);
if (NativeMethods.OpenPrinter(printerName.Normalize(), out printerHandle, IntPtr.Zero))
{
if (NativeMethods.StartDocPrinter(printerHandle, 1, documentInfo))
{
int bytesWritten;
byte[] managedData;
IntPtr unmanagedData;
managedData = document;
unmanagedData = Marshal.AllocCoTaskMem(managedData.Length);
Marshal.Copy(managedData, 0, unmanagedData, managedData.Length);
if (NativeMethods.StartPagePrinter(printerHandle))
{
NativeMethods.WritePrinter(
printerHandle,
unmanagedData,
managedData.Length,
out bytesWritten);
NativeMethods.EndPagePrinter(printerHandle);
}
else
{
throw new Win32Exception();
}
Marshal.FreeCoTaskMem(unmanagedData);
NativeMethods.EndDocPrinter(printerHandle);
}
else
{
throw new Win32Exception();
}
NativeMethods.ClosePrinter(printerHandle);
}
else
{
throw new Win32Exception();
}
}
catch (Exception e)
{
}
}
The Print() command takes the name of the printer and an array of bytes as parameters. The purpose is to open the printer that is named and send the array of bytes as raw data.
I hope there is a solution that uses the printer driver in one way or another, because that abstracts the way the printer is connected. The printer I currently have for testing is connected using USB, but there are also models that have a serial port and can be connected using a Serial to USB cable.
My question:
How would I do the equivalent of the code above in Objective-C?
Has anyone heard of any issues with MessageDialog's not displaying on Windows 8 tablets? Or more specifically Samsung 700t? It uses a regular intel process and not ARM. I built the app on a laptop and the messagedialog shows when debugging from the laptop, shows on the tablet simulator but doesn't show on the actual tablet.
I'm using the Caliburn.Micro IResult interface to display the messagedialog in the view.
Heres snippits of code that I'm using:
public IEnumerable<IResult> NavExecute(String method)
{
Windows.UI.ViewManagement.ApplicationView.TryUnsnap();
var conn = NetworkInformation.GetInternetConnectionProfile();
if (conn.GetNetworkConnectivityLevel() != NetworkConnectivityLevel.InternetAccess)
{
yield return new MessageDialogResult("Internet Connection Not Detected", "Connection Error");
netOn = false;
}
}
the above is in my view model base class, and heres the implementation of the IResult class itself:
public class MessageDialogResult : ResultBase
{
private readonly string _content;
private readonly string _title;
public MessageDialogResult(string content, string title)
{
_content = content;
_title = title;
}
public async override void Execute(ActionExecutionContext context)
{
var dialog = new MessageDialog(_content, _title);
await dialog.ShowAsync();
OnCompleted();
}
}
I doub't it's an issue with the code since I'm debugging in x86 mode on both devices (before anyone asks why I'm not debugging for all devices it's because I'm using SQLite which requires a seperate package for each arhitecture.)
I'm not sure if theres a setting somewhere in Windows 8 that disables in app popups, but I couldn't find one.
Any ideas?
Are you handling the callback of Coroutine.Execute?
The callback on Execute might be calling back with an exception thrown by the coroutine - this would silently fail if you weren't explicitly looking for it in the callback
Coroutine.Execute(YourEnumerator(), new ActionExecutionContext { Blah }, (o, e) => {
if(e.Error != null) // Something went wrong
});
Maybe the async await is throwing or something like that (can't think why!)
Edit:
Ah additionally stuff in your enumerator could also throw:
Windows.UI.ViewManagement.ApplicationView.TryUnsnap();
var conn = NetworkInformation.GetInternetConnectionProfile();
Either one could throw making the outer enumerator swallow an exception if not handled in the callback - or could be a nullref on conn?
The reason why GetInternetConnectionProfile() was returning a null ref was due to the fact that when on a laptop, if you disconnect from a wireless connection the laptop's internet connection profile defaults to ethernet, whereas the tablet (at least the Samsung 700T) doesn't have an ethernet port so it's connection profile doesn't exist if a wireless connection isn't established.
Thanks to Charleh for pointing me in the right direction.