Recently I am writing an app on My PC and lumia 640, everything seems good when it runs under Debug mode in VS 2015, but when I use it on my phone and tap a button to open a FileOpenPicker to choose picture from PicturesLibrary, it just crash...
When I try connecting my phone and use VS to find the problem, it never shows up any more...Also, when I run my app on my PC, whether under Debug mode or not, the problem also never happens.
The Listener of the button looks like this:
private async void OnSnap(object sender, RoutedEventArgs e)
{
try
{
FileOpenPicker fileOpenPicker = new FileOpenPicker();
fileOpenPicker.SuggestedStartLocation = PickerLocationId.PicturesLibrary;
fileOpenPicker.FileTypeFilter.Add(".jpg");
fileOpenPicker.FileTypeFilter.Add(".png");
fileOpenPicker.ViewMode = PickerViewMode.Thumbnail;
var inputFile = await fileOpenPicker.PickSingleFileAsync();
if (inputFile == null)
{
// The user cancelled the picking operation
return;
}
else
{
Windows.Storage.AccessCache.StorageApplicationPermissions.FutureAccessList.Add(inputFile);
Frame frame = Window.Current.Content as Frame;
frame.Navigate(typeof(PictureChoosePage), await inputFile.OpenAsync(FileAccessMode.Read));
}
}
catch (Exception exception)
{
Debug.WriteLine(exception.Message);
var msgDialog = new MessageDialog(exception.Message) { Title = "Unkown Error" };
msgDialog.Commands.Add(new Windows.UI.Popups.UICommand("OK", uiCommand => {
Frame frame = Window.Current.Content as Frame;
frame.Navigate(typeof(MainPage));
}));
msgDialog.Commands.Add(new Windows.UI.Popups.UICommand("Cancel", uiCommand => { }));
await msgDialog.ShowAsync();
return;
}
}
One more thing to mention is that when my App crash, the bottom bar of the FileOpenPicker shows up...like this:
The required permissions should have been declared, and if there is a UnathorizedAccessException thrown, it should be caught by my code...So I'm thinking if this is the bug of the OS since the windows 10 mobile on my lumia 640 is 10.0.14295.1000, just a preview version.
Related
Well, it actually works pretty well on my android studio simulator but when I try to run it on my phone it just crashes.
I just want to send a number to the server and get a response with the data that I need to that number. so this is my code which do that:
thread = new Thread() {
#Override
public void run() {
//server stuff
try {
//Connecting
if(!userClass.equals("")) {
Log.i(debugString, "Attempting to connect to server");
socket = new Socket(hostname, portnumber);
Log.i(debugString, "Connection established!");
BufferedWriter bw = new BufferedWriter((new OutputStreamWriter(socket.getOutputStream())));
bw.write("" + userClass);
bw.newLine();
bw.flush();
BufferedReader br = new BufferedReader(new InputStreamReader(socket.getInputStream()));
input = br.readLine();
}
} catch (IOException e) {
Log.e(debugString, e.getMessage());
} finally {
threadComplete = true;
}
}
};
thread.start();
while(!threadComplete)
continue;
then I just use this thread whenever I want to get the updated info for my request like that:
String getUserClass = userClass;
if(!getUserClass.equals(""))
{
threadComplete = false;
userClass = getUserClass;
thread.start();
while (!threadComplete)
continue;
changes.setText(input);
}
else Toast.makeText(this, "Error, choose your class", Toast.LENGTH_SHORT).show();
BTW, in the end of every thread (on the emulator because on my phone it crashes) I get a message:
Skipped 91 frames! The application may be doing too much work on its main thread.
and I have another problem, I also use IntentService to run my app service on the background, and obviously I don't want it to run constantly forever, so I made a loop which contains at the end of each loop a wait() command, but the problem is that when I set the time to wait for longer than 3000 milliseconds or so, the service crashes.
my code for the background service:
synchronized (this) {
int count = 0;
while (count<4) {
try {
wait(3000);
} catch (InterruptedException e) {
e.printStackTrace();
}
if (notifications && !userClass.equals("")) {
new Thread() {
#Override
public void run() {
//server stuff
try {
//Connecting
if (!userClass.equals("")) {
Log.i("debug", "Attempting to connect to server");
socket = new Socket(hostname, portnumber);
Log.i("debug", "Connection established!");
BufferedWriter bw = new BufferedWriter((new OutputStreamWriter(socket.getOutputStream())));
bw.write("" + userClass);
bw.newLine();
bw.flush();
BufferedReader br = new BufferedReader(new InputStreamReader(socket.getInputStream()));
input = br.readLine();
}
} catch (IOException e) {
Log.e("debug", e.getMessage());
} finally {
complete = true;
}
}
}.start();
while (!complete)
continue;
Toast.makeText(this, "" + input, Toast.LENGTH_SHORT).show();
NotificationManager mNotifyMgr = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
NotificationCompat.Builder mBuilder =
new NotificationCompat.Builder(this)
.setSmallIcon(R.drawable.chanka)
.setContentTitle("ביטול שיעורים: ")
.setContentText(input);
mNotifyMgr.notify(mNotificationId, mBuilder.build());
mNotificationId++;
Toast.makeText(this, "" + input, Toast.LENGTH_SHORT).show();
count++;
}
}
}
This following piece of code is the culprit -
while (!threadComplete)
continue;
You are kind of putting the main thread on a long loop. Android does not allow that. The general construct in these kind of use cases is this -
Step 1 - Show a progress dialog to the user indicating that you are
doing something important and user needs to wait till that is
complete. Show some meaningful text in the progress dialog which makes
sense to the user.
Step 2 - Start a async connection to the server. There are lot of
options in Android to do this. But for your purpose AsyncTask might
be useful. Connect to your server, fetch and parse data in the
doInBackground method of AsyncTask and once the task is complete,
let onPostExecute publish the same to the Main thread.
Step 3 - Once you get back the result from the Async task, you may
dismiss the progress dialog and continue with whatever you were doing.
Please note that the main thread should not be blocked at any time. This is the event handling thread of the app and handles all events (User initiated or system initiated). If the thread is blocked, you get the kind of error you are seeing now. Specifically in your case, Android system is not able to do some draw operations because of the while loop.
Create a new Asynctask and run the socket establisment codes inside it :)
socket = new Socket(hostname, portnumber);
I have a modal Navigation page with an image which acts like a button;
<Image Source ="share.png" HeightRequest="32" WidthRequest="32">
<Image.GestureRecognizers>
<TapGestureRecognizer Tapped="On_Share" />
</Image.GestureRecognizers>
</Image>
And the method behind;
async void On_Share(object sender, EventArgs e)
{
if (CrossConnectivity.Current.IsConnected)
{
var message = "Share this";
var title = "Share";
await CrossShare.Current.Share(new ShareMessage { Text = message, Title = title}, new ShareOptions { ExcludedUIActivityTypes = new[] { ShareUIActivityType.PostToFacebook } });
}
else
{
NoInternetLabel.IsVisible = true;
}
}
I'm getting the error when I try to click on the share image/button. I've put breakpoints into the first line of the On_Share method & they're not being hit.
Warning: Attempt to present <UIActivityViewController: 0x141b60f70> on <Xamarin_Forms_Platform_iOS_ModalWrapper: 0x1419a0920> whose view is not in the window hierarchy!
Please note this works fine in Android, I'm only seeing issues in iOS. I'm not sure what is going on - I'm not trying to present any other windows or anything when I click the image. Regardless, the error appears before the process reaches the beginning of the On_Share method. What am I missing here?
EDIT: The method does get hit now, and I'm still getting the error. It must be trying to send up the share sheet and failing...
There was a problem with the Share plugin in the end - we resolved it by making part of the code recursive.
the GetVisibleViewController used to look like this;
UIViewController GetVisibleViewController()
{
var rootController = UIApplication.SharedApplication.KeyWindow.RootViewController;
if (rootController.PresentedViewController == null)
return rootController;
if (rootController.PresentedViewController is UINavigationController)
{
return ((UINavigationController)rootController.PresentedViewController).VisibleViewController;
}
if (rootController.PresentedViewController is UITabBarController)
{
return ((UITabBarController)rootController.PresentedViewController).SelectedViewController;
}
return rootController.PresentedViewController;
}
whereas it needed to cycle through to find the top UIViewController;
UIViewController GetVisibleViewController(UIViewController controller = null)
{
controller = controller ?? UIApplication.SharedApplication.KeyWindow.RootViewController;
if (controller.PresentedViewController == null)
return controller;
if (controller.PresentedViewController is UINavigationController)
{
return ((UINavigationController)controller.PresentedViewController).VisibleViewController;
}
if (controller.PresentedViewController is UITabBarController)
{
return ((UITabBarController)controller.PresentedViewController).SelectedViewController;
}
return GetVisibleViewController(controller.PresentedViewController);
}
I've raised the issue and submitted a pull request on the github
Testing this to incorporate into Win 10 UWP app to scan 1D barcodes (format 39 & 128). I have updated latest through nuget 2.0.4.46. Referenced post at http://www.yortondotnet.com/2015/07/mobile-barcode-scanning-with-zxingnet.html regarding some options setting prior to scan() with no luck. The scanner (camera) opens but never recognizes a barcode scan successfully - or failure for that matter. It seems nothing is happening whatsoever. I have included straight, pertinent sample code with some options modifications for review. I have gotten Scandit API to work and was going to try Manateeworks but both are really costly and not an option. I am developing on Surface Pro 3 (Win 10) and that build will also be target machines when complete.
public sealed partial class MainPage : Page
{
UIElement customOverlayElement = null;
MobileBarcodeScanner scanner;
public MainPage()
{
this.InitializeComponent();
//Create a new instance of our scanner
scanner = new MobileBarcodeScanner(this.Dispatcher);
scanner.Dispatcher = this.Dispatcher;
}
private void buttonScanDefault_Click(object sender, RoutedEventArgs e)
{
//Tell our scanner to use the default overlay
scanner.UseCustomOverlay = false;
//We can customize the top and bottom text of our default overlay
scanner.TopText = "Hold camera up to barcode";
scanner.BottomText = "Camera will automatically scan barcode\r\n\r\nPress the 'Back' button to Cancel";
// GWS Set Options
var options = new MobileBarcodeScanningOptions();
options.PossibleFormats = new List<ZXing.BarcodeFormat>() {
ZXing.BarcodeFormat.CODE_39, ZXing.BarcodeFormat.CODE_128
};
options.AutoRotate = false;
options.TryHarder = false;
options.TryInverted = false;
//Start scanning
scanner.Scan(options).ContinueWith(t =>
{
if (t.Result != null)
HandleScanResult(t.Result);
});
}
private void buttonScanContinuously_Click(object sender, RoutedEventArgs e)
{
//Tell our scanner to use the default overlay
scanner.UseCustomOverlay = false;
//We can customize the top and bottom text of our default overlay
scanner.TopText = "Hold camera up to barcode";
scanner.BottomText = "Camera will automatically scan barcode\r\n\r\nPress the 'Back' button to Cancel";
// GWS Set Options
var options = new MobileBarcodeScanningOptions();
options.PossibleFormats = new List<ZXing.BarcodeFormat>() {
ZXing.BarcodeFormat.CODE_39, ZXing.BarcodeFormat.CODE_128
};
options.AutoRotate = false;
options.TryHarder = false;
options.TryInverted = false;
//Start scanning
scanner.ScanContinuously(options, async (result) =>
{
var msg = "Found Barcode: " + result.Text;
await Dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal, async () =>
{
await MessageBox(msg);
});
});
}
async void HandleScanResult(ZXing.Result result)
{
string msg = "";
if (result != null && !string.IsNullOrEmpty(result.Text))
msg = "Found Barcode: " + result.Text;
else
msg = "Scanning Canceled!";
await MessageBox(msg);
}
}
Simon,
I have the exact same problem. I tested your code with the latest nuget 2.1.47, the problem still exists.
You need to download the latest from Github and add the following projects (or DLLs) to your project:
ZXing.Net (project: zxing.portable.csproj)
ZXing.Net.Mobile.Core
ZXing.Net.Mobile.WindowsUniversal
I have tested your code and it works fine. I hope this help.
Cheers,
Sam
I think that the problem in the hardware you are testing with. Surface Pro 3 (Win 10) does not have an auto focus camera. I've never succeed to scan with ZXing using my Surface Pro 3, while the same application is working fine with my other windows 10 device.
I can't seem to find the property for the MediaCapture class that allows me to detect the front camera and switch to it if available. Here is my current setup of the device, it all works as expected on Windows (front cam) and Phone (rear cam). None of the Microsoft samples show the front camera being used in Universal or WP 8.1 (WinRT/Jupiter).
mediaCaptureManager = new MediaCapture();
await mediaCaptureManager.InitializeAsync();
if (mediaCaptureManager.MediaCaptureSettings.VideoDeviceId != "" && mediaCaptureManager.MediaCaptureSettings.AudioDeviceId != "")
{
StartStopRecordingButton.IsEnabled = true;
TakePhotoButton.IsEnabled = true;
ShowStatusMessage("device initialized successfully!");
mediaCaptureManager.VideoDeviceController.PrimaryUse = CaptureUse.Video;
mediaCaptureManager.SetPreviewRotation(VideoRotation.Clockwise90Degrees);
mediaCaptureManager.SetRecordRotation(VideoRotation.Clockwise90Degrees);
mediaCaptureManager.RecordLimitationExceeded += RecordLimitationExceeded;
mediaCaptureManager.Failed += Failed;
}
There is a sample on the Microsoft github page that is relevant, although they target Windows 10. Still, the APIs should work on 8/8.1.
UniversalCameraSample: This one does capture photos, and supports portrait and landscape orientations. Here is the relevant part:
private static async Task<DeviceInformation> FindCameraDeviceByPanelAsync(Windows.Devices.Enumeration.Panel desiredPanel)
{
// Get available devices for capturing pictures
var allVideoDevices = await DeviceInformation.FindAllAsync(DeviceClass.VideoCapture);
// Get the desired camera by panel
DeviceInformation desiredDevice = allVideoDevices.FirstOrDefault(x => x.EnclosureLocation != null && x.EnclosureLocation.Panel == desiredPanel);
// If there is no device mounted on the desired panel, return the first device found
return desiredDevice ?? allVideoDevices.FirstOrDefault();
}
And you can use it like so:
// Attempt to get the front camera if one is available, but use any camera device if not
var cameraDevice = await FindCameraDeviceByPanelAsync(Windows.Devices.Enumeration.Panel.Front);
if (cameraDevice == null)
{
Debug.WriteLine("No camera device found!");
return;
}
// Create MediaCapture and its settings
_mediaCapture = new MediaCapture();
var settings = new MediaCaptureInitializationSettings { VideoDeviceId = cameraDevice.Id };
// Initialize MediaCapture
try
{
await _mediaCapture.InitializeAsync(settings);
_isInitialized = true;
}
catch (UnauthorizedAccessException)
{
Debug.WriteLine("The app was denied access to the camera");
}
catch (Exception ex)
{
Debug.WriteLine("Exception when initializing MediaCapture with {0}: {1}", cameraDevice.Id, ex.ToString());
}
Have a closer look at the sample to see how to get all the details. Or, to have a walkthrough, you can watch the camera session from the recent //build/ conference, which includes a little bit of a walkthrough through some camera samples.
Here is how to get the device's available cameras and set the front one for the stream:
mediaCaptureManager = new MediaCapture();
var devices = await DeviceInformation.FindAllAsync(DeviceClass.VideoCapture);
var deviceInfo = devices[0]; //grab first result
foreach (var device in devices)
{
if (device.Name.ToLowerInvariant().Contains("front"))
{
deviceInfo = frontCamera = device;
hasFrontCamera = true;
}
if (device.Name.ToLowerInvariant().Contains("back"))
{
rearCamera = device;
}
}
var mediaSettings = new MediaCaptureInitializationSettings
{
MediaCategory = MediaCategory.Communications,
StreamingCaptureMode = StreamingCaptureMode.AudioAndVideo,
VideoDeviceId = deviceInfo.Id
};
await mediaCaptureManager.InitializeAsync(mediaSettings);
You'll need to consider rotation because front and rear cameras on different devices have different rotations, but this will initialize your MediaCapture properly
I'm trying to create an app that can use the camera for Windows Phone 8.1, using the Windows RT/XAML development model.
When I try to call either of the capture methods off of the MediaCapture class I get an ArgumentException with the message "The parameter is incorrect." Here is my code
private async Task Initialize()
{
if (!DesignMode.DesignModeEnabled)
{
await _mediaCaptureMgr.InitializeAsync();
ViewFinder.Source = _mediaCaptureMgr;
await _mediaCaptureMgr.StartPreviewAsync();
}
}
private async void ViewFinder_OnTapped(object sender, TappedRoutedEventArgs e)
{
ImageEncodingProperties imageProperties = ImageEncodingProperties.CreateJpeg();
var stream = new InMemoryRandomAccessStream();
await _mediaCaptureMgr.CapturePhotoToStreamAsync(imageProperties, stream);
_bitmap = new WriteableBitmap((int) ViewFinder.ActualWidth, (int) ViewFinder.ActualHeight);
stream.Seek(0);
await _bitmap.SetSourceAsync(stream);
PreviewImage.Source = _bitmap;
PreviewElements.Visibility = Visibility.Visible;
ViewFinder.Visibility = Visibility.Collapsed;
Buttons.Visibility = Visibility.Visible;
Message.Visibility = Visibility.Collapsed;
stream.Seek(0);
var buffer = new global::Windows.Storage.Streams.Buffer((uint) stream.Size);
stream.ReadAsync(buffer, (uint) stream.Size, InputStreamOptions.None);
DataContext = buffer.ToArray();
if (PhotoCaptured != null)
PhotoCaptured(this, null);
}
The initialize method is called on page load, and the viewfinder_ontapped is called when they tap the CaptureElement I have in the xaml. The error is thrown on
await _mediaCaptureMgr.CapturePhotoToStreamAsync(imageProperties, stream);
What's really bizarre is that I downloaded the latest source for the winrt xaml toolkit http://winrtxamltoolkit.codeplex.com/ and tried their sample camera app, which uses similar code. It throws the same error on MediaCapture.CapturePhotoToStorageFileAsync(). Can anyone help me identify why?