Trying to get a simple button to play a simple string in using TTS in Xamarin.
Some methods we have tried are
https://developer.xamarin.com/guides/xamarin-forms/application-fundamentals/dependency-service/text-to-speech/#Creating_the_Interface
https://channel9.msdn.com/Shows/XamarinShow/Snack-Pack-7-Plugins-for-Xamarin-and-Windows
The second one is as follows, after adding the plugin to the project and the Android and iOS levels.
using System;
using Xamarin.Forms;
using Plugin.TextToSpeech;
namespace AppOne
{
public partial class MainPage : ContentPage
{
public MainPage()
{
InitializeComponent();
}
private void btnHelp_Clicked(object sender, EventArgs e)
{
CrossTextToSpeech.Current.Speak("Help");
}
}
}
Break point was used to check to see if the line was ever run, it was.
Will this method not work with 2017 and we have to use 2015?
We also are using "Live Player" for testing, could that be an issue?
We have used multiple devices including LG G3, SAMSUNG S2 tablet, and a couple other Andriod devices of friends.
Related
I have already successfully used BLE advertising to broadcast information from one android device and receive it on another. Now I want the observer to be a Unity-app running on the HoloLens v2. The HoloLens does not need to connect to the android-device as I am aware that this does not seem to be supported. I am looking for a broadcaster -> observer solution.
As mentioned, I already have the broadcaster written and it works fine with android -> android. Now I have implemented my observer in Unity, largely inspired by this article, and it looks like this:
#if ENABLE_WINMD_SUPPORT
using System;
using Windows.Devices.Bluetooth.Advertisement;
#endif
public class DemoManager : MonoBehaviour
{
[SerializeField] private StatusDisplay statusDisplay;
private void Awake()
{
#if ENABLE_WINMD_SUPPORT
StartWatcher();
#else
statusDisplay.Display("UWP APIs are not supported on this platform!");
#endif
}
#if ENABLE_WINMD_SUPPORT
private void StartWatcher()
{
void OnAdvertisementReceived(object sender, BluetoothLEAdvertisementReceivedEventArgs eventArgs)
{
statusDisplay.Display("Advertisement received!");
}
try {
BluetoothLEAdvertisementWatcher watcher = new BluetoothLEAdvertisementWatcher();
watcher.AdvertisementFilter.Advertisement.ManufacturerData.Add(GetManufacturerData());
watcher.Received += OnAdvertisementReceived;
watcher.Start();
statusDisplay.Display("Watcher started!");
} catch (Exception e){
statusDisplay.Display($"Watcher could not start! Error: {e.Message}");
}
}
private BluetoothLEManufacturerData GetManufacturerData()
{
var manufacturerData = new BluetoothLEManufacturerData();
manufacturerData.CompanyId = 1234;
return manufacturerData;
}
#endif
}
The StatusDisplay script is used for displaying text in a thread-safe way. The company-id 1234 is also used by the broadcaster.
My app has bluetooth capabilities (enabled both in the Unity-editor and in the built solution)
All looks very promising, but sadly the advertisement never seems to be received, or at the very least I am getting no corresponding status message.
Does anybody have any ide what might be wrong? Does anyone have any experience with this problem?
We tested the Bluetooth.Advertisement API and works well on the HoloLens. I found that you assigned the CompanyId(a 16-bit unsigned integer) property a signed decimal number, but we usually provide a hexadecimal number as a Bluetooth LE company identifier code. Could you double-check this point both in your watcher and publisher? For example, it should look like 0xFFFE. Besides, more information about how to use the Bluetooth Advertisement API to send and receive Bluetooth Low Energy advertisements please see:Bluetooth advertisement sample
The problem was not with the Unity-side. My advertisement was malformed. I tested my advertisements with a observer that I also wrote myself on Android. So I accounted for the incorrect formatting there, but of course, the C# Advertisement-watcher did not.
I'm new to Xamarin.Forms.
I got an app that works well on iOS. However, on Android, it crashes after some time, and throws the following error:
Unhandled Exception:
System.NullReferenceException: Object reference not set to an instance
of an object.
Debug says it happens on this code:
private void OnElementToggled(object sender, EventArgs e)
{
this.Element.IsToggled = this.Control.Checked;
}
This toggle turns an option on or off inside our app. The toggle works fine on iOS. It also works on Android, but if I navigate around the app and switch the toggle on/off a few times, I get the error. I only get this error on Android, and only after I navigate around. Also, I get it at different times on simulator vs device (Galaxy S5 Neo). The simulator can run longer before I get the error.
I'm dumbfounded. How do I fix this?
I've searched and found What is a NullReferenceException, and how do I fix it?. That solution doesn't seem to apply in my case, because my code works fine on iOS and initially on Android.
Thank you very much for your time and help.
Try/Catch is a basic C# concept, any intro book will cover it
private void OnElementToggled(object sender, EventArgs e)
{
try {
this.Element.IsToggled = this.Control.Checked;
catch (Exception ex) {
// use logging (ie, appcenter.ms) to log this exception
}
}
Since the recent update for Codename one any barcode scanning seems to be broken.
On android the camera appears and scans the code but nothing happens when it returns to the app (that is none of the 3 callback functions are triggered).
On iOS the camera window doesn't even appear.
I'm using this library since it doesn't rely on an installed scanning app:
https://github.com/littlemonkeyltd/QRScanner
I had thought the inbuilt scanning functionality may have been removed and passed to this library, so I tried to include that too:
https://github.com/codenameone/cn1-codescan
However it still isn't working on Android. IOS refuses to build with the cn1-codescan library included.
Pretty sure this was all working last week, or the week before.
my code looks like this:
Log.p("Scanning QR code");
QRScanner.scanQRCode(new ScanResult() {
public void scanCompleted(String contents, String formatName, byte[] rawBytes) {
Log.p("QR result:"+contents);
QRResult(contents, formatName, rawBytes);
}
public void scanCanceled() {
Log.p("scan canceled");
}
public void scanError(int errorCode, String message) {
Log.p("error during scan: " + message);
scanFailed();
}
});
edit:
Here are the android build hints added to codenameone_setting.properties when I add the libraries in:
codename1.arg.android.xapplication=<activity android\:name\="com.dm.zbar.android.scanner.ZBarScannerActivity" android\:screenOrientation\="landscape" android\:label\="#string/app_name" />
codename1.arg.android.xpermissions=<uses-permission android\:name\="android.permission.CAMERA"/><uses-feature android\:name\="android.hardware.camera" android\:required\="false"/>
codename1.arg.android.proguardKeep=\ -keep class net.sourceforge.zbar.** {*;}
If you build against the "latest" barcode scanning should work. I'm assuming that you built against 3.5 and not the latest. It's possible that the regression in barcode scanning got into 3.5, this we verified that barcode/qr code scanning works with the latest on the build servers.
I have a Xamarin Forms 2.0 application that uses ZXing.Net.Mobile and ZXing.Net.Mobile.Forms version 2.0.3.1. I'm trying to build a simple QR code scanner, but whenever I launch the ZXingScannerPage on Android I can see the default overlay (with the text and the red line) but I don't see the output of the camera so I can't actually scan anything. I have already listed the Camera permission in my AndroidManifest:
<uses-permission android:name="android.permission.CAMERA" />
I tried the sample code from the readme: https://github.com/Redth/ZXing.Net.Mobile as well as from their Samples/Forms project. I now have this code:
private async void OnScanQrClicked(object sender, EventArgs e)
{
_scannerPage = new ZXingScannerPage();
_scannerPage.OnScanResult += HandleScanResult;
await Navigation.PushAsync(_scannerPage);
}
private void HandleScanResult(Result result)
{
_scannerPage.IsScanning = false;
Device.BeginInvokeOnMainThread(() =>
{
Navigation.PopAsync();
DisplayAlert("Scanned code", result.Text, "OK");
});
}
Some more specs: I'm running Android 5.1 on a Moto G (v1).
Why am I not seeing the output of the camera?
I fixed it by getting rid of ZXing.Net.Mobile.Forms and downgrading ZXing.Net.Mobile from 2.0 to 1.5. I had to change my implementation, but that was relatively easy.
Another thing people may look at in the future (I didn't try it) is adding the flashlight permission: https://github.com/Redth/ZXing.Net.Mobile/issues/227.
I'm making an app where I have to have in app purchases (buying keys that I can further use in the app).
I have looked at this component http://components.xamarin.com/view/xamarin.inappbilling, but I have no idea how I can implement this in xamarin forms. Is there anyone out there willing to help me with this problem? Is there any open source projects with in app purchase that I can look at?
I know its late, but this might help someone:
The way to do achieve this is to create a service and then surface it to a standard interface (as per your requirement) that will be consumed within the forms project.
You can even use MessagingCenter to communicate between Android and Xamarin.Forms project.
FormsPrject:
MessagingCenter.Send<MainPage, string>(this, "BuyProduct", "buyButtonPressed");
AndroidPoject
MessagingCenter.Subscribe<MainPage, string>(this, "BuyProduct", (sender, arg) =>
{
//logic to buy product
}
Hope that helps!!
The question is very vague so I will offer a general answer and some notes that I found important. I am using Visual Studio 2015 with Xamarin Forms 2.3.0.107.
I would use abstraction for this instead of sending messages directly between the projects.
The basic idea is, you will create a public interface in your Xamarin Forms project. Since your Andriod project has a reference to the Xamarin Forms project, it can use this public interface. Then you will implement this interface in your Android project will all of the billing logic. In the Xamarin Forms project. Using the Dependency service we can get the existing instance of the implementation into the Xamarin Forms project. Then, you can code against the interface. This is especially useful if you ever want to do an iPhone or other implementation, because you would never need to make changes to the Xamarin Forms code; you can just plug in new implementations.
It might be a bit out of scope but, be sure to meet all of the Google requirements as far as setting up your developer account and your merchant account and your API account. It is all very confusing and messy.
The Xamarin component in nuget is currently version 1.5. However, the component has a newer published version. You want to use the newer (2.0 or higher) version.
Use the Android SDK manager to install the Google Play Billing Library.
In your Android project, add a reference to Xamarin.InAppBilling and add a Xamarin.InAppBilling component.
The Google object has to live in an Android activity, because you depend on overriding an activity method to complete purchases (I used the MainActivity here and made the google object a static for easy access)
Testing this with Google Play is a hassle. The documentation is confusing because of differences between versions. You cannot use actual product id's until you publish your app. They provide test id's that can be used during testing but they only offer some functionality.
I have made these code examples as minimal as possible to illustrate the concept. You will obviously want to do much more.
Xamarin Forms project
Create an interface:
public interface IInAppBilling
{
void Pay(string productId);
}
Any time you want to use the billing service, you use IInAppBilling billingService = DependencyService.Get<IInAppBilling>(); to get a reference to the device-specific (Android) implementation.
//call this from a button click or whatever
void BuySomething(string somethingId)
{
//Get any IInAppBilling object that is registered with the DependencyService.
IInAppBilling billingService = DependencyService.Get<IInAppBilling>();
billingService.Pay(somethingId);
}
Android Project
Override an activity's OnCreate method and create an InAppBillingServiceConnection:
public class MainActivity : global::Xamarin.Forms.Platform.Android.FormsApplicationActivity
{
public static InAppBillingServiceConnection google;
protected override void OnCreate(Bundle bundle)
{
base.OnCreate(bundle);
google = new InAppBillingServiceConnection(this, "MII...ApplicationKey");
global::Xamarin.Forms.Forms.Init(this, bundle);
LoadApplication(new App());
}
}
Create a class that implements the Xamarin Forms interface we created earlier. It is important not to ignore the assembly: Dependencyannotation at the top. This is what makes the class available to the Dependency service in the Xamarin Forms object:
[assembly: Dependency(typeof(com.myapp.InAppBilling))]
namespace com.myapp
{
class InAppBilling :IInAppBilling
{
public void Pay(string productId)
{
MainActivity.google.BillingHandler.BuyProduct(productId, ItemType.Product, "MyUniquePayload");
}
}
}
Override the activity's OnActivityResult method to finalize purchases:
protected override void OnActivityResult(int requestCode, Result resultCode, Intent data)
{
base.OnActivityResult(requestCode, resultCode, data);
// Ask the open service connection's billing handler to process this request
try
{
google.BillingHandler.HandleActivityResult(requestCode, resultCode, data);
}
catch (Exception ex)
{
//log it or something?
}
}