I am building a Windows 8 application using sql-net and mvvmcross for data access to a sqlite database. This would be applicable to any Win-8 or Win-Phone app.
I need to install an existing sqlite file on app start.
When using the connection you use syntax such as this
public FlashCardManager(ISQLiteConnectionFactory factory, IMvxMessenger messenger)
{
_messenger = messenger;
_connection = factory.Create("Dictionary.sqlite");
_connection.CreateTable<FlashCardSet>();
_connection.CreateTable<FlashCard>();
}
public void CreateCard(FlashCard flashCard)
{
_connection.Insert(flashCard);
}
That connection creates a file in: C:\Users\USER\AppData\Local\Packages\793fd702-171e-474f-ab3b-d9067c58709b_ka9b83fa3fse2\LocalState
My application uses an existing sqlite database file that I have created. I need to place it in this folder when the application is installed. How would I go about doing this?
Thanks,
JH
Make sure you have the database file you want your app to start off with in one of your apps folders (as in the folders visible in visual studios solution explorer). For this example I'll call this folder "Assets"
All you need to do then is copy this file to the LocalState folder the first time your app runs. This can be done in App.xaml.cs
private async void InitializeAppEnvironment()
{
try
{
if (!(await AppHelper.ExistsInStorageFolder(AppHelper.localFolder, dbName)))
{
StorageFile defaultDb = await AppHelper.installedLocation.GetFileAsync("Assets\\" + dbName);
await defaultDb.CopyAsync(AppHelper.localFolder);
}
}
catch (Exception e)
{
System.Diagnostics.Debug.WriteLine(e);
}
}
I made an AppHelper class to simplify accessing the app data folders, here's the parts I used above:
static class AppHelper
{
public static StorageFolder installedLocation = Windows.ApplicationModel.Package.Current.InstalledLocation;
public static StorageFolder localFolder = ApplicationData.Current.LocalFolder;
public static async Task<bool> ExistsInStorageFolder(this StorageFolder folder, string fileName)
{
try
{
await folder.GetFileAsync(fileName);
return true;
}
catch (FileNotFoundException)
{
return false;
}
}
}
For a more detailed response on MVVM cross I found the current discussion about cross platform file placement in this discussion: Link
The current thought is that you have to inject platform specific code for this sort of functionality.
Related
I am trying to create a simple GET API endpoint which will return the JSON of the current environment appsettings.json file, for example for the development environment it will return the contents of appsettings.Development.json file and for production environment it will return the contents of appsettings.Production.json file.
I don't know a nice way to dump the entire config file. What I know though is ways to read single config values through the injected config["Key"] or read a section through
config.GetSection("SectionName").Get<MyCustomSectionClass>()
approach. These options are not feasible as the file is big and the content may change.
This is an ASP.NET Core 6 Core Web API application, created through the default Visual Studio template.
If you want to return entire appsettings.xxx.json file, You can try this simple demo. I not sure if there is a better method, But this method works well in my project.
using Newtonsoft.Json;
private readonly IWebHostEnvironment _env;
public WeatherForecastController(IWebHostEnvironment env)
{
_env = env;
}
[HttpGet]
public IActionResult Get()
{
if (_env.IsDevelopment())
{
var path = Path.Combine(_env.ContentRootPath, "appsettings.Development.json");
string json = System.IO.File.ReadAllText(path);
object jsonObject = JsonConvert.DeserializeObject(json);
return Ok(jsonObject);
}else if (_env.IsProduction())
{
//read from appsettings.Production.json
return Ok();
}
else
{
//..........
return Ok();
}
}
what is the proper way to create an EF Core database on an Android/iOS device with Xamarin.Forms and EntityFrameworkCore?
I've come across the EnsureCreated vs Migrate thing and since I'm planning on changing the database structure in the future, I'd like to be able to apply those migrations to an existing database, thus I've chosen the Migrate approach.
However, when I call the Migrate method, it doesn't seem to create a database. I've managed to make it work in case I copy the pre-generated database file on the devices beforehand, but that's not what I want. Is there a way to tell EF Core to check if there's an existing database, create a new database if not, and then apply pending migrations to it?
Here's what I've done so far:
I've created a .net standard class library "Data" that will hold all my database classes (context, models, and migrations).
I've changed the TargetFramework of the "Data" project from <TargetFramework>netstandard2.0</TargetFramework> to <TargetFrameworks>netcoreapp2.0;netstandard2.0</TargetFrameworks> so I could run PMC commands on it.
I've installed these nuget packages to the "Data" project:
EntityFrameworkCore
EntityFrameworkCore.Sqlite
EntityFrameworkCore.Tools
EntityFrameworkCore.Design
I've created a database context class. I've made two constructors for it. The default one will only be used by the PMC commands for generating migrations. The other one will be used in production.
public class MyTestContext : DbContext
{
private string _databasePath;
public DbSet<Issue> Issues { get; set; }
[Obsolete("Don't use this for production. This is only for creating migrations.")]
public MyTestContext() : this("nothing.db")
{
}
public MyTestContext(string databasePath)
{
_databasePath = databasePath;
}
protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
{
//I've also tried Filename={_databasePath} here, didn't work either
optionsBuilder.UseSqlite($"Data Source={_databasePath}");
}
}
I've created a test model class, just to have something to play with
public class Issue
{
public string Id { get; set; }
}
I created an inital migration using this command, which completed successfully:
Add-Migration Migration001 -Context MyTestContext -Output Migrations
I added a call to the Migrate method in the App.xaml.cs of my Xamarin.Forms project to test if it works.
public partial class App : Application{
//... other code
protected override async void OnStart()
{
base.OnStart();
using (var db = new MyTestContext(_dbPath))
{
try
{
db.Database.Migrate();
db.Issues.Add(new Issue
{
Id = "TestIssueId"
});
db.SaveChanges();
}
catch (Exception ex)
{
Debug.WriteLine(ex);
}
}
}
//... other code
}
The _dbPath variable contains this (on Android where I'm testing it):
Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Personal), "test.db");
After all this, I'm getting this exception:
Microsoft.Data.Sqlite.SqliteException: SQLite Error 1: 'no such table: Issues'.
I have a dotnet core console application build to connect to a Sql Service Broker instance to monitor table changes.
The app monitors one table that is updated from an ERP system and then publishes messages to our bus.
It runs fine when running as a console application, or debugging in my IDE.
I am having an issue when using TopShelf to configure it as a windows service.
Here is the entry point:
private static void Main(string[] args)
{
RegisterComponents();
var serviceHost = HostFactory.Run(sc =>
{
sc.Service<ISalesOrderMonitorService>(s =>
{
var sqlListener = _container.ResolveNamed<SqlDependencyEx>(ListenerKey.SalesOrder);
var changeHandler = _container.Resolve<ISalesOrderChangeHandler>();
var listenerConfig = _container.ResolveNamed<ListenerConfiguration>(ListenerKey.SalesOrder);
var logger = _container.Resolve<ILogger<SalesOrder>>();
s.ConstructUsing(f =>
new SalesOrderMonitorService(sqlListener, changeHandler, listenerConfig, logger));
s.WhenStarted(tc => tc.Start());
s.WhenStopped(tc => tc.Stop());
});
});
var exitCode = (int) Convert.ChangeType(serviceHost, serviceHost.GetType());
Environment.ExitCode = exitCode;
}
The "worker" class:
public abstract class ServiceBase<T, TZ> : IService<T>
where T : IChangeHandler
{
protected readonly IChangeHandler ChangeHandler;
protected readonly SqlDependencyEx Listener;
protected readonly ListenerConfiguration ListenerConfiguration;
protected readonly ILogger<TZ> Logger;
protected ServiceBase(SqlDependencyEx listener, IChangeHandler changeHandler,
ListenerConfiguration listenerConfiguration, ILogger<TZ> logger)
{
Logger = logger;
ListenerConfiguration = listenerConfiguration;
Listener = listener;
ChangeHandler = changeHandler;
}
public virtual void Start()
{
try
{
Listener.TableChanged += (o, e) => ChangeHandler.Process(e);
Listener.Start();
Logger.LogDebug(
$"Listening to changes on the {ListenerConfiguration.Table} table in the {ListenerConfiguration.Database} database");
}
catch (Exception e)
{
Logger.LogError(e, e.Message);
throw;
}
}
public virtual void Stop()
{
Listener.Stop();
}
Install through TopShelf is no problem:
c:>{ServiceName}.exe install -username "serviceAccount" -password "superSecret" -servicename "ServiceName" -servicedescription "Description" -displayname "Service DisplayName" --autostart
When I go to start the service - I get this:
This is misleading because the event viewer shows this:
This is happening way faster than 30 seconds. This is definitely related to how I am configuring TopShelf.
As stated - the application works just fine when run "debug" or even as just an exe console.
I got it figured out. Actually both comments from #DotNetPadawan and #Lex Li indirectly got me there.
For starters - enabling the remote debugger clued me in that my appsetting.json was not being read into my IConfiguration. That was really confusing because everything works fine running locally with a debugger or even just starting the exe.
The link Lex Li points out did not provide the answer - however that article had this reference:
Host and Deploy aspnetcore as a Windows Service
It was here that I found this little nugget:
The current working directory returned by calling GetCurrentDirectory for a Windows Service is the C:\WINDOWS\system32 folder. The system32 folder isn't a suitable location to store a service's files (for example, settings files). Use one of the following approaches to maintain and access a service's assets and settings files.
The link explains how to conditionally set the current directory if the app is running as a service.
var isConsole = args.Contains("-mode:console");
if (!isConsole)
{
var pathToExe = Process.GetCurrentProcess().MainModule?.FileName;
var pathToContentRoot = Path.GetDirectoryName(pathToExe);
Directory.SetCurrentDirectory(pathToContentRoot);
}
Putting this out there for anyone else that runs into this problem.
Admittedly - netcore 3.0 is likely the better way to go - but I don't have the bandwidth to upgrade everything is this repo (lots of shared stuff) to 3.0. I needed to get this working.
can anyone guide me on how to perform a reload of an apache commons configuration2 properties. I'm unable to find any implementation of this anywhere. The apache docs are a bit too abstract. This is what I have so far but it's not working.
CombinedConfiguration cc = new CombinedConfiguration();
Parameters params = new Parameters();
File configFile = new File("config.properties");
File emsFile = new File("anotherconfig.properties");
ReloadingFileBasedConfigurationBuilder<FileBasedConfiguration> configBuilder =
new ReloadingFileBasedConfigurationBuilder<FileBasedConfiguration>(PropertiesConfiguration.class)
.configure(params.fileBased()
.setFile(configFile));
PeriodicReloadingTrigger reloadTrg = new PeriodicReloadingTrigger(configBuilder.getReloadingController(), null, 5, TimeUnit.SECONDS);
reloadTrg.start();
cc.addConfiguration(configBuilder.getConfiguration());
FileBasedConfigurationBuilder<FileBasedConfiguration> emsBuilder =
new FileBasedConfigurationBuilder<FileBasedConfiguration>(PropertiesConfiguration.class)
.configure(params.properties()
.setFile(emsFile));
cc.addConfiguration(emsBuilder.getConfiguration());
DataSource ds = EmsDataSource.getInstance().getDatasource(this);
BasicConfigurationBuilder<DatabaseConfiguration> dbBuilder =
new BasicConfigurationBuilder<DatabaseConfiguration>(DatabaseConfiguration.class);
dbBuilder.configure(
params.database()
.setDataSource(ds)
.setTable("EMS_CONFIG")
.setKeyColumn("KEY")
.setValueColumn("VALUE")
);
cc.addConfiguration(dbBuilder.getConfiguration());
The configuration obtained from a builder is not updated automatically. You need to get the configuration from the builder every time you read it.
From Automatic Reloading of Configuration Sources:
One important point to keep in mind when using this approach to reloading is that reloads are only functional if the builder is used as central component for accessing configuration data. The configuration instance obtained from the builder will not change automagically! So if an application fetches a configuration object from the builder at startup and then uses it throughout its life time, changes on the external configuration file become never visible. The correct approach is to keep a reference to the builder centrally and obtain the configuration from there every time configuration data is needed.
use following code:
#Component
public class ApplicationProperties {
private PropertiesConfiguration configuration;
#PostConstruct
private void init() {
try {
String filePath = PropertiesConstants.PROPERTIES_FILE_PATH;
System.out.println("Loading the properties file: " + filePath);
configuration = new PropertiesConfiguration(filePath);
//Create new FileChangedReloadingStrategy to reload the properties file based on the given time interval
FileChangedReloadingStrategy fileChangedReloadingStrategy = new FileChangedReloadingStrategy();
fileChangedReloadingStrategy.setRefreshDelay(PropertiesConstants.REFRESH_DELAY);
configuration.setReloadingStrategy(fileChangedReloadingStrategy);
} catch (ConfigurationException e) {
e.printStackTrace();
}
}
public String getProperty(String key) {
return (String) configuration.getProperty(key);
}
public void setProperty(String key, Object value) {
configuration.setProperty(key, value);
}
public void save() {
try {
configuration.save();
} catch (ConfigurationException e) {
e.printStackTrace();
}
}
}
When using msdeploy to do a sync operation, one of the things that MSDeploy checks to determine if a file should be synced or not is the attributes on the file (readonly, archive, etc.). If the attributes are different between the two copies of the file, then the file will be synced. Is there a way to tell MSDeploy to ignore file attributes when determining if a file should be synced or not?
It is possible, however, not merely on the command line. You'd have to build a custom DeploymentRuleHandler, like this:
namespace CustomRuleHandlers
{
using Microsoft.Web.Deployment;
[DeploymentRuleHandler]
internal class IgnoreFileAttributesRuleHandler : DeploymentRuleHandler
{
public override int CompareAttribute(DeploymentSyncContext syncContext, DeploymentObject destinationObject, DeploymentObjectAttribute destinationAttribute, DeploymentObject sourceObject, DeploymentObjectAttribute sourceAttribute, int currentComparison)
{
if ((destinationObject.Name.Equals("filePath", StringComparison.Ordinal))
&& destinationAttribute.Name.Equals("attributes", StringComparison.Ordinal))
{
return 0;
}
return currentComparison;
}
public override string Description
{
get { return "Ignores file attributes when determining if a file should be synched or not."; }
}
public override string FriendlyName
{
get { return "IgnoreFileAttributes"; }
}
public override string Name
{
get { return "IgnoreFileAttributes"; }
}
public override bool EnabledByDefault
{
get { return false; }
}
}
}
Compile that into an assembly (targeting .Net 3.5 for WebDeploy v2!) and put the assembly into the "Extensibility" subfolder in the WebDeploy folder (normally, C:\Program Files\IIS\Microsoft Web Deploy V2\Extensibility).
Then, you can easily leverage your custom rule when running msdeploy from the command-line by adding this argument:
-enableRule:IgnoreFileAttributes
Of course, that assembly needs to be present on both, the source and the target machine, of a sync operation.
Unfortunately, there's no easier way of getting there!