Xamarin.Android doesn't create SQLite database - xamarin.android

I'm trying to create a database with Xamarin.Android but both on the emulator and on the tablet I do not receive an error but nothing is created, where am I wrong?
protected override void OnCreate(Bundle bundle)
{
base.OnCreate(bundle);
// Set our view from the "main" layout resource
SetContentView(Resource.Layout.Main);
// create variables for our onscreen widgets
var btnCreate = FindViewById<Button>(Resource.Id.btnCreateDB);
// create DB path
var docsFolder = System.Environment.GetFolderPath(System.Environment.SpecialFolder.MyDocuments);
var pathToDatabase = System.IO.Path.Combine(docsFolder, "db_sqlnet.db");
// disable the single and list buttons until the database has been created
btnSingle.Enabled = btnList.Enabled = false;
// create events for buttons
btnCreate.Click += delegate
{
var result = createDatabase(pathToDatabase);
txtResult.Text = result + "\n";
// if the database was created ok, then enable the list and single buttons
if (result == "Database created")
btnList.Enabled = btnSingle.Enabled = true;
};
private string createDatabase(string path)
{
try
{
var connection = new SQLiteConnection(path);
connection.CreateTable< Entity.Person>();
return "Database created";
}
catch (SQLiteException ex)
{
return ex.Message;
}
}

In you I would use the folder System.Environment.SpecialFolder.Personal instead of System.Environment.SpecialFolder.MyDocuments.
End when you open the connection with new SQLiteConnection(path) try to add SQLiteOpenFlags.ReadWrite | SQLiteOpenFlags.Create as second parameter.

Related

Model value not being set in Xamarin in iOS Only

I am working on a Xamarin App where I am facing an issue.
Case 1:
Mode: Debug
Error: System.NullReferenceException: 'Object reference not set to an instance of an object'
Explanation:
No value is being set and passed to ViewModel, Controller.
Even I tried setting static values to variables and parameters.
LoginModel logtest = new LoginModel();
logtest.Username = "Test#user.com"; //uName;
logtest.Password = "2342534"; //pWord;
Tried solution:
In the beginning, I tried many different solutions nothing worked.
Then I create a new project and moved all the code to the new project, then it started working.
Case 2:
Mode: release
Now the same issue I am getting in release mode.
No value is being set and passed to ViewModels and Controller.
I have already tried moving code to a new project.
How can I resolve this? I am not sure is this a Visual studio issue or Xamarin issue or Apple.
I have tried updating Visual Studio enterprise 2019 and Xcode on Mac.
Deleted and recreated Provisioning Profiles and Signing Identities.
Code From LoginPage.xaml.cs
private async void LoginButtonClicked(object sender, EventArgs e)
{
await ((LoginViewModel)BindingContext).Login();
}
protected async override void OnAppearing()
{
//App.Current.MainPage = new Navigation(new DashboardPage());
//load the login page
Device.BeginInvokeOnMainThread(() =>
{
try
{
((LoginViewModel)BindingContext).IsLoading = false;
((LoginViewModel)BindingContext).RememberMe = DeviceStorage.RememberMe;
if (DeviceStorage.RememberMe == true)
{
((LoginViewModel)BindingContext).UserName = "Test#user.ca"; //Trying set static values here
((LoginViewModel)BindingContext).Password = "password"; //Trying set static values here
}
//RememberMeToggle.Toggled += switcher_Toggled;
((LoginViewModel)BindingContext).Load();
}
catch (Exception ex)
{
//logger.Error(App.LogPrefix() + "Error opening Navigation Page: " + ex.Message);
Console.WriteLine(App.LogPrefix() + "Error opening Load(): " + ex.Message);
}
});
}
Code from LoginViewModel.cs
public async Task Login()
{
IsLoading = true;
await TokenController.GetAuthorizationToken(UserName, Password);
}
Code from TokenController.cs
public static async Task GetAuthorizationToken(string uName, string pWord)
{
bool tokenReturned = false;
string tokenGetResponse = string.Empty;
// Have tried setting them static values as well
LoginModel logtest = new LoginModel();
logtest.Username = uName;
logtest.Password = pWord;
logtest.AppType = Constants.AppDetails.APP_CODE;
logtest.SystemCode = Constants.AppDetails.SYSTEM_CODE;
logtest.Push.PushSystem = PushAddressModel.PushSystemCode.FireBase;
logtest.Push.Address = ((App)App.Current).PushNotificationToken;
logtest.Push.AppCode = Constants.AppDetails.APP_CODE;
string uri = URI.message_Chat_Endpoint;
(tokenReturned, tokenGetResponse) = await ApiFunctions.Post(logtest, URI.token_Endpoint, false);
if (tokenReturned)
{
try
{
//deserialize the return object
TokenModel token = JsonConvert.DeserializeObject<TokenModel>(tokenGetResponse);
((App)App.Current).token = token;
}
catch (Exception ex)
{
Console.WriteLine("Error: " + ex.Message);
//logger.Error(App.LogPrefix() + "Error: " + ex.Message);
}
Console.WriteLine("Profile Token loaded: " + ((App)App.Current).token.access_token);
}
else
{
Console.WriteLine("Error: Error loading profile token ");
//logger.Error(App.LogPrefix() + "Error loading profile token");
}
}

Installing Umbraco programmatically

I'm trying to install Umbraco without using the visual interface, in order to increase my productivity.
Currently my code looks like this:
var installApiController = new InstallApiController();
var installSetup = installApiController.GetSetup();
var instructions = new Dictionary<string, JToken>();
var databaseModel = new DatabaseModel
{
DatabaseType = DatabaseType.SqlCe
};
var userModel = new UserModel
{
Email = "my#email.com",
Name = "My name",
Password = "somepassword",
SubscribeToNewsLetter = false
};
foreach (var step in installSetup.Steps)
{
if (step.StepType == typeof(DatabaseModel))
{
instructions.Add(step.Name, JToken.FromObject(databaseModel));
}
else if (step.StepType == typeof(UserModel))
{
instructions.Add(step.Name, JToken.FromObject(userModel));
}
}
var installInstructions = new InstallInstructions
{
InstallId = installSetup.InstallId,
Instructions = instructions
};
InstallProgressResultModel progressInfo = null;
do
{
string stepName = "";
if (progressInfo != null)
{
stepName = progressInfo.NextStep;
}
try
{
progressInfo = installApiController.PostPerformInstall(installInstructions);
}
catch (Exception e)
{
throw new Exception(stepName, e);
}
}
while (progressInfo.ProcessComplete == false);
The code fails at this line: https://github.com/umbraco/Umbraco-CMS/blob/dev-v7.8/src/Umbraco.Web/Install/InstallSteps/NewInstallStep.cs#L47, and I believe it's because the ApplicationContext isnt updated for each of the installation steps (e.g. not updated after the database is created).
Is it possible to update the ApplicationContext manually after each step in the installation progress, or do I have to trigger all installation steps in separate HTTP requests?
The code works, if I run each step in separate HTTP requests.

How can i get HttpClient to work with NTLM in a pcl with android

have the following which works on Win10 phone in a pcl.
But i cannot get the same code to return OK on samsung s7 with android 7.0
project is xamarin forms.
nuget for system.net.http is 2.2.29.
I've include the same nuget in my UWP for the win10 phone and android projects.
i've also changed the user to include be "domain\user", "domain#user", "user#domain"
var httpClientHandler = new System.Net.Http.HttpClientHandler()
{
Credentials = credentials.GetCredential(new Uri(location), "NTLM")
};
I've tried and alternative to setting the httpClientHandler.Credentials.
var credentials = new NetworkCredentials("user", "pass", "domain");
var location = "http://apps.mysite.com/api#/doit";
var httpClientHandler = new HttpClientHandler{
Credentials = credentials
}
using (var httpClient = new HttpClient(httpClientHandler, true))
{
httpClient.DefaultRequestHeaders.Accept.Clear();
httpClient.DefaultRequestHeaders.Accept.Add(new System.Net.Http.Headers.MediaTypeWithQualityHeaderValue("application/json"));
httpClient.DefaultRequestHeaders.Add("X-FORMS_BASED_AUTH_ACCEPTED", "f");
try
{
var httpResponseMessage = await httpClient.GetAsync(location);
if (httpResponseMessage.StatusCode != System.Net.HttpStatusCode.OK)
{
//handle error
}
else
{
//do something
}
}
catch (Exception)
{}
finally
{}
}
another strange thing. when i run this on android, the code hits the await httpclient.getasync(location);
and the immediately jumps to the finally.
I hava a simple form with username & password Entry Fields, plus an OK button.
all three controls are bound to a viewmodel. the OK button via an ICommand.
this code and the view live in the PCL. which has a reference to Microsoft.Net.Http.
I have Android and Universal Windows Xamarin forms builds that consume the PCL.
Android Properties. Default httpClient, SSL/TLS Default. supported arch armeabi, armeabi-v7a;x86
Android Manifest: Camera, flashlight and internet
private bool calcEnabled = false;
private ICommand okCommand;
private string message = string.Empty;
private string validatingMessage = "Validating!";
private string unauthorizedMessage = "Invalid Credentials!";
private string authenticatedMessage = "Validated";
private bool validating = false;
public ICommand OkCommand => okCommand ?? (okCommand = new Command<object>((o) => clicked(o), (o) => CalcEnabled));
protected async void clicked(object state)
{
try
{
Validating = true;
Message = validatingMessage;
var credentials = new
System.Net.NetworkCredential(Helpers.Settings.UserName, Helpers.Settings.Password, "www.domain.com");
var location = "http://apps.wwwoodproducts.com/wwlocator#/information";
var httpClientHandler = new System.Net.Http.HttpClientHandler()
{
Credentials = credentials.GetCredential(new Uri(location), "NTLM") };
using (var httpClient = new System.Net.Http.HttpClient(httpClientHandler))
{
httpClient.DefaultRequestHeaders.Accept.Clear();
httpClient.DefaultRequestHeaders.Accept.Add(new System.Net.Http.Headers.MediaTypeWithQualityHeaderValue("application/json"));
httpClient.DefaultRequestHeaders.Add("X-FORMS_BASED_AUTH_ACCEPTED", "f");
try
{
var httpResponseMessage = await
httpClient.GetAsync(location);
if (httpResponseMessage.StatusCode != System.Net.HttpStatusCode.OK)
{
Message = unauthorizedMessage;
}
else
{
Message = authenticatedMessage;
Messenger.Default.Send<bool>(true);
}
}
catch (Exception)
{
Message = unauthorizedMessage;
}
finally
{
Validating = false;
}
}
}
catch (Exception)
{
throw;
}
}

C# VS WP8 Linking a created tile to a Uri Scheme

First i create a tile with this code:
private void btnIconicTile_Click(object sender, RoutedEventArgs e)
{
IconicTileData oIcontile = new IconicTileData();
oIcontile.Title = "Hello Iconic Tile!!";
oIcontile.Count = 7;
oIcontile.IconImage = new Uri("Assets/Tiles/Iconic/202x202.png", UriKind.Relative);
oIcontile.SmallIconImage = new Uri("Assets/Tiles/Iconic/110x110.png", UriKind.Relative);
oIcontile.WideContent1 = "windows phone 8 Live tile";
oIcontile.WideContent2 = "Icon tile";
oIcontile.WideContent3 = "All about Live tiles By WmDev";
oIcontile.BackgroundColor = System.Windows.Media.Colors.Black;
// find the tile object for the application tile that using "Iconic" contains string in it.
ShellTile TileToFind = ShellTile.ActiveTiles.FirstOrDefault(x => x.NavigationUri.ToString().Contains("Iconic".ToString()));
if (TileToFind != null && TileToFind.NavigationUri.ToString().Contains("Iconic"))
{
TileToFind.Delete();
ShellTile.Create(new Uri("/MainPage.xaml?id=Iconic", UriKind.Relative), oIcontile, true);
}
else
{
ShellTile.Create(new Uri("/MainPage.xaml?id=Iconic", UriKind.Relative), oIcontile, true);//
}
}
Now i want that the created tile in the homescreen links to an app (Uri Scheme?) like this on for ex:
await Windows.System.Launcher.LaunchUriAsync(new System.Uri("whatsapp:"));
How i can modify the "link" of that recently created tile?
Yes i need too.
Windows.System.Launcher.LaunchUriAsync(new System.Uri("whatsapp:"))
homescreen

Issue in Invoking camera and saving images in SD card

In my task I have to invoke camera in a button click and take picture and have to save it and display the image in the same screen. I have tried it and succeed in emulator. but its not working in real device. getting some errors. tried a lot. but cant able to find out the issue. more over, Its working perfectly in 9700 emulator and showing some error in 9500.
public class CameraScreen extends MainScreen implements FieldChangeListener
{
/** The camera's video controller */
private VideoControl _videoControl;
private Field _videoField;
private EncodingProperties[] _encodings;
private int _indexOfEncoding = 0;
private static String FILE_NAME = System.getProperty("fileconn.dir.photos")+"IMAGE"; //"file:///SDCard/" + "myphotos/" + "IMAGE";//
private static String EXTENSION = ".bmp";
private static int _counter;
int flag = 0;
BitmapField imageField = new BitmapField();
HorizontalFieldManager menuBar = new HorizontalFieldManager(Field.USE_ALL_WIDTH);
VerticalFieldManager main_vfm = new VerticalFieldManager();
VerticalFieldManager camera_vfm = new VerticalFieldManager();
VerticalFieldManager image_vfm = new VerticalFieldManager();
ButtonField bt = new ButtonField("Click",ButtonField.CONSUME_CLICK);
ButtonField front_bt = new ButtonField("Front",ButtonField.CONSUME_CLICK);
ButtonField back_bt = new ButtonField("Back",ButtonField.CONSUME_CLICK);
ButtonField side1_bt = new ButtonField("Side 1",ButtonField.CONSUME_CLICK);
ButtonField side2_bt = new ButtonField("Side 2",ButtonField.CONSUME_CLICK);
public CameraScreen()
{
setTitle("First Screen");
bt.setChangeListener(this);
front_bt.setChangeListener(this);
back_bt.setChangeListener(this);
side1_bt.setChangeListener(this);
side2_bt.setChangeListener(this);
image_vfm.add(menuBar);
menuBar.add(front_bt);
menuBar.add(back_bt);
menuBar.add(side1_bt);
menuBar.add(side2_bt);
image_vfm.add(bt);
try {
Bitmap image = Bitmap.createBitmapFromBytes( readFile(),0, -1, 5 );
imageField.setBitmap(image);
image_vfm.add(imageField);
} catch(Exception e) {
System.out.println(e.toString());
}
main_vfm.add(image_vfm);
add(main_vfm);
front_bt.setFocus();
// Initialize the camera object and video field
initializeCamera();
// Initialize the list of possible encodings
initializeEncodingList();
// If the field was constructed successfully, create the UI
if(_videoField != null)
{
createUI();
}
// If not, display an error message to the user
else
{
camera_vfm.add( new RichTextField( "Error connecting to camera." ) );
}
}
/**
* Takes a picture with the selected encoding settings
*/
public void takePicture()
{
try
{
// A null encoding indicates that the camera should
// use the default snapshot encoding.
String encoding = null;
if( _encodings != null )
{
// Use the user-selected encoding
encoding = _encodings[_indexOfEncoding].getFullEncoding();
}
// Retrieve the raw image from the VideoControl and
// create a screen to display the image to the user.
createImageScreen( _videoControl.getSnapshot( encoding ) );
}
catch(Exception e)
{
home.errorDialog("ERROR " + e.getClass() + ": " + e.getMessage());
}
}
/**
* Prevent the save dialog from being displayed
* #see net.rim.device.api.ui.container.MainScreen#onSavePrompt()
*/
protected boolean onSavePrompt()
{
return true;
}
/**
* Initializes the Player, VideoControl and VideoField
*/
private void initializeCamera()
{
try
{
// Create a player for the Blackberry's camera
Player player = Manager.createPlayer( "capture://video" );
// Set the player to the REALIZED state (see Player javadoc)
player.realize();
// Grab the video control and set it to the current display
_videoControl = (VideoControl)player.getControl( "VideoControl" );
if (_videoControl != null)
{
// Create the video field as a GUI primitive (as opposed to a
// direct video, which can only be used on platforms with
// LCDUI support.)
_videoField = (Field) _videoControl.initDisplayMode (VideoControl.USE_GUI_PRIMITIVE, "net.rim.device.api.ui.Field");
_videoControl.setDisplayFullScreen(true);
//_videoControl.setDisplaySize(50, 50);
_videoControl.setVisible(true);
}
// Set the player to the STARTED state (see Player javadoc)
player.start();
}
catch(Exception e)
{
home.errorDialog("ERROR " + e.getClass() + ": " + e.getMessage());
}
}
/**
* Initialize the list of encodings
*/
private void initializeEncodingList()
{
try
{
// Retrieve the list of valid encodings
String encodingString = System.getProperty("video.snapshot.encodings");
// Extract the properties as an array of word
String[] properties = StringUtilities.stringToKeywords(encodingString);
// The list of encodings
Vector encodingList = new Vector();
//Strings representing the four properties of an encoding as
//returned by System.getProperty().
String encoding = "encoding";
String width = "width";
String height = "height";
String quality = "quality";
EncodingProperties temp = null;
for(int i = 0; i < properties.length ; ++i)
{
if( properties[i].equals(encoding))
{
if(temp != null && temp.isComplete())
{
// Add a new encoding to the list if it has been
// properly set.
encodingList.addElement( temp );
}
temp = new EncodingProperties();
// Set the new encoding's format
++i;
temp.setFormat(properties[i]);
}
else if( properties[i].equals(width))
{
// Set the new encoding's width
++i;
temp.setWidth(properties[i]);
}
else if( properties[i].equals(height))
{
// Set the new encoding's height
++i;
temp.setHeight(properties[i]);
}
else if( properties[i].equals(quality))
{
// Set the new encoding's quality
++i;
temp.setQuality(properties[i]);
}
}
// If there is a leftover complete encoding, add it.
if(temp != null && temp.isComplete())
{
encodingList.addElement( temp );
}
// Convert the Vector to an array for later use
_encodings = new EncodingProperties[ encodingList.size() ];
encodingList.copyInto((Object[])_encodings);
}
catch (Exception e)
{
// Something is wrong, indicate that there are no encoding options
_encodings = null;
home.errorDialog(e.toString());
}
}
/**
* Adds the VideoField to the screen
*/
private void createUI()
{
// Add the video field to the screen
camera_vfm.add(_videoField);
}
/**
* Create a screen used to display a snapshot
* #param raw A byte array representing an image
*/
private void createImageScreen( byte[] raw )
{
main_vfm.replace(camera_vfm, image_vfm);
fieldChanged(raw);
Bitmap image1 = Bitmap.createBitmapFromBytes( readFile(),0, -1, 5 );
try{
if(flag == 1){
}
else{
image_vfm.delete(imageField);
}
imageField.setBitmap(image1);
image_vfm.add(imageField);
}
catch(Exception e){System.out.println(e.toString());}
}
private byte[] readFile() {
byte[] result = null;
FileConnection fconn = null;
try {
fconn = (FileConnection)Connector.open(FILE_NAME + "_front" + EXTENSION);
} catch (IOException e) {
System.out.print("Error opening file");
}
if (!fconn.exists()) {
//Dialog.inform("file not exist");
} else {
InputStream in = null;
ByteVector bytes = new ByteVector();
try {
in = fconn.openInputStream();
} catch (IOException e) {
System.out.print("Error opening input stream");
}
try {
int c = in.read();
while (-1 != c) {
bytes.addElement((byte) c);
c = in.read();
}
result = bytes.getArray();
} catch (IOException e) {
System.out.print("Error reading input stream");
}
try {
fconn.close();
} catch (IOException e) {
System.out.print("Error closing file");
}
}
return result;
}
public void fieldChanged( final byte[] _raw )
{
try
{
flag ++;
// Create the connection to a file that may or
// may not exist.
FileConnection file = (FileConnection)Connector.open(FILE_NAME + "_front" + EXTENSION);
// If the file exists, increment the counter until we find
// one that hasn't been created yet.
if (file.exists()) {
file.delete();
file.close();
file = (FileConnection) Connector.open(FILE_NAME + "_front" + EXTENSION);
}
//FileConnection file_temp = (FileConnection)Connector.open(FILE_NAME + "tempimg" + EXTENSION);
//file_temp.delete();
// We know the file doesn't exist yet, so create it
file.create();
// Write the image to the file
OutputStream out = file.openOutputStream();
out.write(_raw);
// Close the connections
//out.close();
file.close();
//Dialog.inform( "Saved to " + FILE_NAME + "_front" + EXTENSION );
}
catch(Exception e)
{
home.errorDialog("ERROR " + e.getClass() + ": " + e.getMessage());
Dialog.inform( "File not saved this time");
}
}
/**
* Sets the index of the encoding in the 'encodingList' Vector
* #param index The index of the encoding in the 'encodingList' Vector
*/
public void setIndexOfEncoding(int index)
{
_indexOfEncoding = index;
}
/**
* #see net.rim.device.api.ui.Screen#invokeAction(int)
*/
protected boolean invokeAction(int action)
{
boolean handled = super.invokeAction(action);
if(!handled)
{
switch(action)
{
case ACTION_INVOKE: // Trackball click
{
takePicture();
return true;
}
}
}
return handled;
}
public void fieldChanged(Field field, int context) {
// TODO Auto-generated method stub
srn2 screen2 = new srn2();
srn3 screen3 = new srn3();
srn4 screen4 = new srn4();
if(field==bt)
{
main_vfm.replace(image_vfm, camera_vfm);
}
if(field==back_bt)
{
UiApplication.getUiApplication().popScreen(UiApplication.getUiApplication().getActiveScreen());
UiApplication.getUiApplication().pushScreen(screen2);
}
if(field==side1_bt)
{
UiApplication.getUiApplication().popScreen(UiApplication.getUiApplication().getActiveScreen());
UiApplication.getUiApplication().pushScreen(screen3);
}
if(field==side2_bt)
{
UiApplication.getUiApplication().popScreen(UiApplication.getUiApplication().getActiveScreen());
UiApplication.getUiApplication().pushScreen(screen4);
}
}
}
Note: This Error displaying first "javax.microedition.media.MediaException: There is already another active Player. Call Player.close() on the existing Player to free up the resources." and camera gets open and when i try to take picture this error displays "Error Class Java.lang.ArrayIndexOutOfBoundsException: Index 0>=0"
After _videoControl.getSnapshot( encoding ) has been called you need to close player (i.e. to call player.close(). And that's exactly what the exception tells about.
However this method of taking images is highly unreliable - you'll not be able to use it for every BB device model. I don't know why RIM put it in SDK samples. By doing that RIM pushes developers to a wrong way. As alishaik786 mentiones a proper method of taking images on BB is using Invoke.invokeApplication(Invoke.APP_TYPE_CAMERA, new CameraArguments()) with a FileSystemJournalListener implementation. Just search on StackOverflow on these for the implementation details. I vaguely recall the implementation is painful (like many other parts on BB), but once done it will work on any device.
you got two error
1."javax.microedition.media.MediaException: There is already another active Player. Call Player.close()
this exception thrown if you try to open camera (player) while another instance of camera is already opened. In your code, you need to define the player object as a class level and must close the player after taking the snapshot (also need to close the player if you push from one screen to another).
2."Error Class Java.lang.ArrayIndexOutOfBoundsException: Index 0>=0"
This error may occur when you access encoding array while encoding array size is zero.
You can ensure this issue by using _videoControl.getSnapshot( null), which take the snapshot in default encoding.
So first insure these issue and reply me.

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