I've created an app using MVVMCross, the IOS and Android versions are working but when I tried to "port" to WP7 and I ran into the following problem:
throw methodAccessException.MvxWrap("Problem accessing object - most likely this is caused by an anonymous object being generated as Internal - please see http://stackoverflow.com/questions/8273399/anonymous-types-and-get-accessors-on-wp7-1");
As mentioned in the answer to my other question about this (on Android) you have to set an InternalsVisibleTo attribute in the AssemblyInfo.cs for WP7. So I did:
[assembly: InternalsVisibleTo("Cirrious.MvvmCross.WindowsPhone")]
But this doesn't make any difference. I use the following code to send two variables form my BeckhoffViewModel to my BeckhoffSensorViewModel.
BeckhoffViewModel:
public IMvxCommand BeckhoffSensor1
{
get
{
return new MvxRelayCommand(kvpSens1);
}
}
private void kvpSens1()
{
RequestNavigate<BeckhoffSensorViewModel>(new { VarType = "short", Variable = ".countertest" });
}
BeckhoffSensorViewModel:
public BeckhoffSensorViewModel(string VarType, string Variable)
{
_vartype = VarType;
_variable = Variable;
}
Anything I'm overlooking? I also looked at the other stackoverflow topic mentioned in the exception but couldn't really understand it.
The anonymous class will most definitely be created as internal by the compiler - which is why you need the line [assembly: InternalsVisibleTo("Cirrious.MvvmCross.WindowsPhone")]
Can you check that the AssemblyInfo.cs file definitely being linked into the project (and that this is the project containing the ViewModel/anonymous-class code)?
If that is the case, can you check the methodAccessException to see what the message is?
If that doesn't help, can you use a tool like Reflector to check the internalVisible attribute is actually present on the core/application assembly?
Related
I am developing a mod_plugin for Moodle and want to support the automatic activity completion with a custom rule. I followed the official documentation and implemented all necessary functions. In the lib.php [pluginname]_supports method I have registered, FEATURE_GRADE_HAS_GRADE, FEATURE_COMPLETION_TRACKS_VIEWS, FEATURE_COMPLETION_HAS_RULES.
The \mod_[pluginname]\completion\custom_completion class defines a custom rule named "completiontest" in get_defined_custom_rules(). During my tests I found out that the methods get_state(), get_sort_order() and get_custom_rule_descriptions() are never executed. Also I don't see any output via activity_information().
I have cleared all caches, created new instances of my activity module, with no result. My development environment uses Moodle 3.11.7 (Build: 20220509).
My custom_completion.php script:
<?php
declare(strict_types=1);
namespace mod_cwr\completion;
use core_completion\activity_custom_completion;
class custom_completion extends activity_custom_completion {
public function get_state(string $rule): int {
return COMPLETION_INCOMPLETE;
}
public static function get_defined_custom_rules(): array {
return [
'completiontest'
];
}
public function get_custom_rule_descriptions(): array {
return [
'completiontest' => 'testout'
];
}
public function get_sort_order(): array {
return [
'completionview',
'completiontest',
'completionusegrade'
];
}
}
Test at the view.php:
$completion = new completion_info($course);
$completion->set_module_viewed($coursemodule);
if($completion->is_enabled($coursemodule) == COMPLETION_TRACKING_AUTOMATIC){
$completion->update_state($coursemodule, COMPLETION_INCOMPLETE, $USER->id);
}
$completiondetails = \core_completion\cm_completion_details::get_instance($coursemodule, $USER->id);
$activitydates = \core\activity_dates::get_dates_for_module($coursemodule, $USER->id);
echo $OUTPUT->activity_information($coursemodule, $completiondetails, $activitydates);
At the mod_form.php I check with completion_rule_enabled() if a custom rule is activated by the settings.
Does anyone have any idea what the problem could be?
Looking at the mod_forum plugin code showed me, that the get_state($rule) method does not observe all custom rules, only those selected in the settings. How do I tell Moodle to use a specific custom rule?
You appear to be calling update_state() and passing in the possible state change as COMPLETION_INCOMPLETE.
This is a way of telling Moodle "if the state is already incomplete, don't bother doing any expensive completion calculations to check if it should change state".
If you want Moodle to check and then (potentially) change the state to "complete", then pass COMPLETION_COMPLETE. If you really don't know which way it could be switching, then leave the param at the default COMPLETION_UNKNOWN (a good example would be forum completion - if you have just created a forum post, then you might cause the forum to be marked as "complete", but you certainly can't cause the forum to be marked as "incomplete", so you can pass the COMPLETION_COMPLETE parameter, so Moodle knows it only needs to check for changes if the forum is not already "complete").
Also, don't bother passing $USER->id as the third parameter - that's the default which is used of you don't pass anything.
As for telling Moodle which rules to use - it is up to you, when your function is called, to check your plugins settings to determine which rules are in use (and any other relevant configuration - e.g. with mod_forum, it needs to check how many posts are required for completion).
Thank you for the support. Got it running.
I now use $completion->update_state($coursemodule, COMPLETION_COMPLETE); and also had to fix [pluginname]_get_coursemodule_info() with $result->customdata['customcompletionrules']['completiontest'] = $cwr->completiontest; and totally forgot the return $result;.
Using Xamarin Forms Visual Studio 2019.
I need to get the DPI of the device.
This post has a solution:
How to get DPI device to PCL in Xamarin. Forms?
Implementing the solution gave problems:
When applying the answer above I get this error message:
The type or namespace name 'DependencyAttribute' could not be found
(are you missing a using directive or an assembly reference?)
In your android implementation, add a new class:
[assembly: Dependency(typeof(DisplayInfo))]
namespace .....
--I solved this compiler problem by replacing with:
using Xamarin.Essentials;
[assembly: Xamarin.Forms.Dependency(typeof(DisplayInfo))]
However when I compile and run the code, it falls over when I try consume this in the Xamarin Core Code:
int dpi = DependencyService.Get<IDisplayInfo>().GetDisplayDpi();
I get this runtime error on the above line:
System.NullReferenceException: Object reference not set to an instance
of an object
Any ideas? I would have added this question as a comment on the original, but as a new user do not have the points to do this... If someone could drop a comment on the original question's solution pointing it to this URL that would be helpful too.
So the answer to my own question:
The solution original offered said do this:
In your android implementation, add a new class:
[assembly: Dependency(typeof(DisplayInfo))]
namespace YourAppNamespace.Droid
{
public class DisplayInfo : IDisplayInfo
{
public int GetDisplayWidth()
{
(int)Android.App.Application.Context.Resources.DisplayMetrics.WidthPixels;
}
public int GetDisplayHeight()
{
(int)Android.App.Application.Context.Resources.DisplayMetrics.HeightPixels;
}
public int GetDisplayDpi()
{
(int)Android.App.Application.Context.Resources.DisplayMetrics.DensityDpi;
}
}
}
The problem I did not see anywhere in the Android code that initialised this class, and I was unsure how best to do this really.
So I followed guidance for implementing the interface directly in the Android MainActivity.cs file, and this worked.. The video I watched to help me on that is here:
https://www.youtube.com/watch?v=lgcnYDb6cRQ&t=19s
I'm trying to configure the SignalR JSon serializer to handle reference loops in my objects graph.
I have seen similar questions on SO, and borrowed the code below from there.
Following is the relevant part of the ConfigureServices method:
services.AddSignalR().AddJsonProtocol(options =>
{
options.PayloadSerializerSettings.PreserveReferencesHandling = PreserveReferencesHandling.Objects;
options.PayloadSerializerSettings.ReferenceLoopHandling = ReferenceLoopHandling.Serialize;
});
Unfortunately, even with this configuration, trying to send data on the wire throws the following exception:
Self referencing loop detected for property 'Vehicule' with type 'A.B.C.Vehicle'. Path ...
Obviously this code is not enough, but I can't figure out what to do.
Any help appreciated.
Add ShouldSerializePROPERTYNAME entry to your model source file:
public bool ShouldSerializeVehicule()
{
return false;
}
or apply the attribute [JsonIgnore] to Vehicule.
This tells Json to skip it.
I was using Breeze v1.1.2 that came with the Hot Towel template which has now been extended to form my project. I made the mistake of updating the NuGet package to the current 1.3.3 (I never learn). Anyway, all was well, and now not so much!
I followed the instructions in the release notes and other docs to change my BreezeWebApiConfig file to:
[assembly: WebActivator.PreApplicationStartMethod(
typeof(BreezeWebApiConfig), "RegisterBreezePreStart")]
namespace MyApp.App_Start {
public static class BreezeWebApiConfig {
public static void RegisterBreezePreStart() {
GlobalConfiguration.Configuration.Routes.MapHttpRoute(
name: "BreezeApi",
routeTemplate: "breeze/{controller}/{action}"
);}}}
And the config.js file (which provides the serviceName to the EntityManager constructor) to:
var remoteServiceName = 'breeze/breeze'; // NEW version
//var remoteServiceName = 'api/breeze'; // OLD version
And my BreezeController if you're interested:
[BreezeController]
public class BreezeController : ApiController
{
readonly EFContextProvider<MyDbContext> _contextProvider =
new EFContextProvider<MyDbContext>();
[HttpGet]
public string Metadata()
{
return _contextProvider.Metadata();
}
[HttpGet]
public IQueryable<SomeItem> SomeItems()
{
// Do stuff here...
}
}
Now I get the "cannot execute _executeQueryCore until metadataStore is populated" error.
What am I missing here?
EDIT:
I perhaps left out the part you needed... Above in the SomeItems() method, the stuff that actually gets done is a call to the GetMeSomeData() method in the MyDBContext class. This method makes the following call to a stored procedure to get the data.
public virtual ObjectResult<SomeItem> GetMeSomeData(string inParam)
{
var p = new object[] { new SqlParameter("#inParam", inParam) };
var retVal = ((IObjectContextAdapter)this).ObjectContext.ExecuteStoreQuery<SomeItem>("exec GetData #SN", p);
return retVal;
}
Now given my limited understanding, the call to Metadata() is not failing, but I don't think it has any idea what the entity model is when coming back, even though somewhere along the line, it should figure that out from the entity model I do have (i.e. SomeItem)? The return string from Metadata() doesn't have any information about the entity. Is there a way to make it aware? Or am I just completely off in left field playing with the daisies?
Hard to say based on this report. Let's see if Breeze is right.
Open the browser debugging tools and look at the network traffic. Do you see an attempt to get metadata from the server before you get that error? If so, did it succeed? Or 404? Or 500? What was the error?
I'm betting it didn't even try. If it didn't, the usual reason is that you tried some Breeze operation before your first query ... and you didn't ask for metadata explicitly either. Did you try to create an entity? That requires metadata.
The point is, you've got to track down the Breeze operation that precipitates the error. Sure everything should just work. The world should be rainbows and unicorns. When it isn't, we heave a sigh, break out the debugger, and start with the information that the error gave us.
And for the rest of you out there ... upgrading to a new Breeze version is a good thing.
Happy coding everyone.
Follow-up to your update
Breeze doesn't know how you get your data on the back-end. If the query result has a recognizable entity in it, Breeze will cache that. It's still up to you in the query callback to ensure that what you deliver to the caller is something meaningful.
You say that you're server-side metadata method doesn't have any idea what SomeItem is? Then it's not much use to the client. If it returns a null string, Breeze may treat that as "no metadata at all" in which case you should be getting the "cannot execute _executeQueryCore until metadataStore is populated" error message. Btw, did you check the network traffic to determine what your server actually returned in response to the metadata request (or if there was such a request)?
There are many ways to create Metadata on the server. The easiest is to use EF ... at least as a modeling tool at design time. What's in that MyDbContext of yours? Why isn't SomeItem in there?
You also can create metadata on the client if you don't want to generate it from the server. You do have to tell the Breeze client that you've made that choice. Much of this is explained in the documentation "Metadata Format".
I get the feeling that you're kind of winging it. You want to stray from the happy path ... and that's cool. But most of us need to learn to walk before we run.
It appears the MSDN docs are broken concerning creating an Event Log completely along with a definitions file for messages. I am also lost on how to setup Categories (I have custom numbers in the 3000's for messages).
Can anyone point me to a link or show sample code on how to make this right?
You should start (if you haven't done so already) here:
EventLogInstaller Class (System.Diagnostics)
The sample provided there is the foundation for what you want to do. To sum it up, build a public class inheriting from System.Configuration.Install.Installer in an assembly (could be the same DLL where you have the rest of your application, a separate DLL, or an EXE file), decorate it with the RunInstaller attribute, and add your setup code in the constructor:
using System;
using System.Configuration.Install;
using System.Diagnostics;
using System.ComponentModel;
[RunInstaller(true)]
public class MyEventLogInstaller: Installer
{
private EventLogInstaller myEventLogInstaller;
public MyEventLogInstaller()
{
// Create an instance of an EventLogInstaller.
myEventLogInstaller = new EventLogInstaller();
// Set the source name of the event log.
myEventLogInstaller.Source = "NewLogSource";
// Set the event log that the source writes entries to.
myEventLogInstaller.Log = "MyNewLog";
// Add myEventLogInstaller to the Installer collection.
Installers.Add(myEventLogInstaller);
}
}
When you have your assembly compiled, you may use the InstallUtil tool available through the Visual Studio Command Prompt to run the installer code.
Regarding the message definition file (which includes category definitions), the MSDN documentation for EventLogInstaller.MessageResourceFile mentions that you should create an .mc file, compile it, and add it as a resource to your assembly. Digging around, I found an excellent post which should guide you to the end, here:
C# with .NET - Event Logging (Wayback Machine)