Scheduled Task Code for a Windows Form - winforms

I made a Windows Form Application and it works great.
But now I got a requirement that needs that the application reads parameters to be able to run as a Scheduled Task.
I made my research and with the instructions
Environment.GetCommandLineArgs();
I can read and do stuff with the parameters, that will replace the user interaction like the combo selection that the application requires,etc.
My big questions is Where do you place the code?
A) Code After the InitializeComponent() in the form. (I dont understand if the code in the form_load will enter if I use it as a hidden Scheduled Task)
B) In the Program.cs after the Application.Run(new Form1());
C) Any other place

be able to run as a Scheduled Task
With no user interaction (and thus no need for a user interface), a Console Application would be ideal for this. And the main entry point for a Console Application is Program.cs. Therein, command-line arguments are even by default passed to the entry point:
static void Main(string[] args)
{
// "args" contains command line arguments
}
So I suspect the ideal setup here would be to have two separately deployed application instances (one as a Windows Form Applications and one as a Console Application), which share business logic in a Class Library, and separately handle the two different usage scenarios you describe.
Think of it like this... Why try to force the same tool to do two very different jobs when you can just use the right tool for each job? (Golden hammers are traditionally bad things.)
If you really want to use the Windows Forms Application as the scheduled task, then it too has the same Program.cs entry point. By default it's usually something like this:
[STAThread]
static void Main()
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(new Form1());
}
But the behavior of the entry point is the same. You can simply add the method arguments and perform logic based on that command-line input. Perhaps something like this:
[STAThread]
static void Main(string[] args)
{
if (CheckForSomeArg(args))
{
// perform the automated tasks, pretend to be a Console Application
}
else
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(new Form1());
}
}
So if the command-line arguments you're looking for are given, the "scheduled task" is performed. Otherwise, the user interface is displayed.

Related

How to slow down the speed of execution?

I am using selenium web-driver with testing. I want to slow down the speed of execution.
Here is the sample code:
#Parameters({ "provider_name", "branch", "address", "clientId", "website", "UserName", "Password", "Dpid" })
public void addDematAccount(String provider_name, String branch, String address, String clientId, String website,
String UserName, String Password, String Dpid) {
driver.findElement(By.xpath("//a[contains(#href, '#/app/DematAccount/Add')]")).click();
setParameter(provider_name, branch, address, clientId, website, UserName, Password, Dpid);
driver.manage().timeouts().implicitlyWait(60, TimeUnit.SECONDS);
I have used driver.manage().timeouts().implicitlyWait(60, TimeUnit.SECONDS); and Thread.sleep(2000); but not helping
There is no longer any way to control the speed of each "step" in Selenium WebDriver. At one time, there was a setSpeed() method on the Options interface (in the Java bindings; other bindings had similar constructs on their appropriately-named objects), but it was deprecated long, long ago. The theory behind this is that you should not need to a priori slow down every single step of your WebDriver code. If you need to wait for something to happen in the application you're automating, you should be using an implicit or explicit wait routine.
If you want to view it, and its too fast I would think you could maybe record your test being executed and then review it ?
See here : http://www.seleniummonster.com/boost-up-your-selenium-tests-with-video-recording-capability/
And here : http://unmesh.me/2012/01/13/recording-screencast-of-selenium-tests-in-java/
Here is some examples from the above link
public void startRecording() throws Exception
{
GraphicsConfiguration gc = GraphicsEnvironment.getLocalGraphicsEnvironment().getDefaultScreenDevice().getDefaultConfiguration();
this.screenRecorder = new ScreenRecorder(gc,
new Format(MediaTypeKey, MediaType.FILE, MimeTypeKey, MIME_AVI),
new Format(MediaTypeKey, MediaType.VIDEO, EncodingKey, ENCODING_AVI_TECHSMITH_SCREEN_CAPTURE,
CompressorNameKey, ENCODING_AVI_TECHSMITH_SCREEN_CAPTURE,DepthKey, 24, FrameRateKey, Rational.valueOf(15),QualityKey, 1.0f,KeyFrameIntervalKey, 15 * 60),new Format(MediaTypeKey,MediaType.VIDEO, EncodingKey, "black",FrameRateKey, Rational.valueOf(30)),null);
this.screenRecorder.start();
}
public void stopRecording() throws Exception
{
this.screenRecorder.stop();
}
The whole purpose of automated tests ( in my opinion ) is so they can be run in the background without user interaction/without being viewed. Also, if you want to do as many tests as possible in a certain about of time speed and parallized testing is essential. If you want to view your tests being executed I think the above method would be good to ensure you don't ruin the performance of Selenium and view the execution when completed, you will have full control with the video to replay etc.
If you really want to execute your program slowly or even step by step, you can try the following approaches:
execute your program in debug mode one step at a time;
refactor your code into function blocks, only execute a block of code at one time, you will not see you code being executed slowly as in time, but it becomes easier for you to associate your codes with the results.

await Task.Delay(...) freezes if there exists a System.Windows.Forms.Form instance

The following program hangs on the DoTheStuff().Wait(); line, if running as a Console application:
namespace Test
{
using System.Threading.Tasks;
using System.Windows.Forms;
class Program
{
static void Main(string[] args)
{
new Form();
DoTheStuff().Wait();
}
private static async Task DoTheStuff()
{
await Task.Delay(1000);
}
}
}
It works just as expected though, if you comment out the new Form(); line. (Runs for 1sec, then quits).
How can I keep the expected behaviour and still have a Form instance?
Now, some background if you are interested:
I have an application which is hosted as a windows service (as console when testing locally).
It requires to have access to the SystemEvents.TimeChanged event.
However, as per the documentation, this only works when having a windows Form (thus not in a service or console app). A workaround is presented in the linked documentation, and consists of creating a hidden form.
Unfortunately, the program now completely freezes instead, which is caused by the combination of await and having a Form instance.
So how on earth can I still have the expected async/await behaviour while accessing the SystemEvents.TimeChanged event?
Thanks to help below, here comes modified code which works without freeze:
namespace Test
{
using System.Threading;
using System.Threading.Tasks;
using System.Windows.Forms;
class Program
{
static void Main(string[] args)
{
new Thread(() => Application.Run(new Form())).Start();
// SynchronizationContext.SetSynchronizationContext(null);
DoTheStuff().Wait();
}
private static async Task DoTheStuff()
{
await Task.Delay(1000);
}
}
}
In my program, I need to use "SynchronizationContext.SetSynchronizationContext(null);", since the threadpool should be used for awaiting tasks. I don't think that is a good practice, since Form obviously initialized it for a reason. But running the form hidden without user input (it is a service!), and can't see any harm right now.
The documentation feels a bit incomplete, with MS not even mentioning the issue that may arise using the example 2 (await/async implicitly changes behaviour when instantiating a Form).
This is by design. Creating a new Form object get the Winforms plumbing to install a new SynchronizationContext. Something you can see in the debugger by looking at the SynchronizationContext.Current property.
That property is big deal whenever you do anything asynchronously. If it is null, the default, then using await gets code to run on threadpool threads. If it is not then the await plumbing will implement the await by calling the SynchronizationContext.Post() method. Which ensures that your code runs on the main thread.
But that doesn't work in your program because you broke the contract. You didn't call Application.Run(). Required.
The SystemEvents class will create its own hidden notification window and pumps a message loop if you don't provide one. No need to create a form. The consequence is that its events will fire on an arbitrary thread, not your main thread. So do watch out for locking requirements.
The call to Wait causes a deadlock, as I explain on my blog and in a recent MSDN article.
In your case, you could use a simple MainAsync as such:
static void Main(string[] args)
{
MainAsync().Wait();
}
static async Task MainAsync()
{
new Form();
await DoTheStuff();
}
private static async Task DoTheStuff()
{
await Task.Delay(1000);
}
However, there are a couple of problems here. First, when you create a form (even a hidden form), you are expected to run an STA event loop, e.g., Application.Run. Second, as a Win32 service, you are expected to give your main thread back to the SCM, e.g., ServiceBase.Run.
So I would recommend a solution where you create a form and run an event loop on a secondary thread.

Event upon initialization complete in WPF/Prism app

In non-Prism WPF app, if I want to run code after initialization (e.g. execute the task specified by command-line argument), I can do it in Loaded event of the main window. However with Prism, the modules are initialized after main window is displayed, that is, IModule.Initialize() is called after Bootstrapper.CreateShell() and Bootstrapper.InitializeShell(). In this case which event/override should I use?
The last thing called by UnityBootstrapper.Run(bool runWithDefaultConfiguration) is InitializeModules() (well apart from a call to Logger.Log). So overide Run(...).
class Bootstrapper : UnityBootstrapper
{
...
public override void Run(bool runWithDefaultConfiguration)
{
base.Run(runWithDefaultConfiguration);
// modules (and everything else) have been initialized when you get here
}
}

Reliably Restart a Single-Instance WPF application

I would like to have my current application close and restart. I have seen many posts on this, however none of these seem to work for me.
I have tried
System.Diagnostics.Process.Start(System.Windows.Application.ResourceAssembly.Location);
System.Windows.Application.Current.Shutdown();
However this only restarts the application once. If I press my 'restart' button again (on the already restarted app), it only closes.
I have also tried launching a new System.Diagnostics.Process and closing the current process, but again this does not restart, it simply closes.
How can I restart my current WPF application?
You could create another application which you start when exiting your app and which in return does start your application again. Kind of like how a patcher would work, only without patching anything. On the plus side you could have a loop in that "restart-application" which checks all running processes for your main application process and only tries to re-start it once it does not appear in the process any longer - and you got the bare bones for a patcher also :) Whilst you do not seem to have a problem with restarting your application due to it still being in the processlist - it is the way I would go for when doing it in a production environment as this gives you the most control IMHO.
Edit:
That part in the button event handler (or wherever you want to restart your app with) of your main app (Process2BRestarted.exe in my case):
private void cmdRestart_Click(object sender, EventArgs e)
{
var info = new ProcessStartInfo();
info.FileName = "ProcessReStarter";
info.WindowStyle = ProcessWindowStyle.Hidden;
Process.Start(info);
Application.Exit();
}
This should go into your utility/restarter application (ProcessReStarter.exe over here):
private void MainForm_Load(object sender, EventArgs e)
{
// wait for main application process to end
// really should implement some kind of error-checking/timer here also
while (Process.GetProcessesByName("Process2BRestarted").Count() > 0) { }
// ok, process should not be running any longer, restart it
Process.Start("Process2BRestarted");
// and exit the utility app
Application.Exit();
}
Clicking the restart button will now create a new process ProcessReStarter.exe, which will iterate through the process list of all running processes - checking whether Process2BRestarted is still running. If the process does not appear in the list (any longer) it will now start a new Process2BRestarted.exe process and exit itself.

Runtime debugging tips for Windows Service?

I have a Windows Service that monitors a COM port connected to a vendors hardware. This is a very busy piece of hardware that is constantly polling other devices on the wire (this is a twisted-pair RS485 "network"). My software needs to emulate X number of hardware devices on this wire, so I've got a multi-threaded thing going on with a multi-tiered state machine to keep track of where the communications protocol is at any moment.
Problem is with a Windows Service (this is my first one, BTW) is that you need some debugging to let you know if stuff is working properly. When I was first developing this state machine/multi-thread code I had a windows form with a RichTextBox that displayed the ASCII chars going back-n-forth on the line. Seems like I can't really have that GUI niceness with a service. I tried opening a form in the service via another program that sent the service messages that are received via the OnCustomCommand() handler but it didn't seem to work. I had "Allow service to interact with desktop" checked and everything. I was using the Show() and Hide() methods of my debug form.
I guess I don't need to see all of the individual characters going on the line but man that sure would be nice (I think I really need to see them :-) ). So does anyone have any crazy ideas that could help me out? I don't want to bog down the system with some IPC that isn't meant for the voluminous amount of data that is sure to come through. It will only be very short-term debugging though, just confirmation that the program, the RS485-to-USB dongle, and hardware is all working.
Use OutputDebugString to write to the debugging buffer and then use DebugView to watch it. If you're running on Windows XP or earlier, then you can use PortMon to see the raw bytes going through the serial port. The advantage over a log file is that there's very little overhead, particularly when you're not watching it. You can even run DebugView from another machine and monitor your service remotely.
I dunno if it will work for you, but I always build my services with a extra Main that build them as console app to get debug output.
Edit:
Some example:
class Worker : ServiceBase
{
#if(RELEASE)
/// <summary>
/// The Main Thread where the Service is Run.
/// </summary>
static void Main()
{
ServiceBase.Run(new Worker());
}
#endif
#if(DEBUG)
public static void Main(String[] args)
{
Worker worker = new Worker();
worker.OnStart(null);
Console.ReadLine();
worker.OnStop();
}
#endif
// Other Service code
}
You could write the output to a log file and then use another application to watch that file. This question about "tail" outlines several options for watching log files with windows.
What I usually do when working on a Windows Service is to create it so that it can be run either as a service, or as a plain old command-line application. You can easily check whether you are running as a service by checking Environment.UserInteractive. If this property is true, then you are running from the command line. If the property is false, then you are running as a service. Add this code to Program.cs, and use it where you would normally call ServiceBase.Run(servicesToRun)
/// <summary>Runs the provided service classes.</summary>
/// <param name="servicesToRun">The service classes to run.</param>
/// <param name="args">The command-line arguments to pass to the service classes.</param>
private static void RunServices(IEnumerable<ServiceBase> servicesToRun, IEnumerable args)
{
var serviceBaseType = typeof(ServiceBase);
var onStartMethod = serviceBaseType.GetMethod("OnStart", BindingFlags.Instance | BindingFlags.NonPublic);
foreach (var service in servicesToRun)
{
onStartMethod.Invoke(service, new object[] { args });
Console.WriteLine(service.ServiceName + " started.");
}
Console.WriteLine("Press any key to exit.");
Console.ReadKey();
var onStopMethod = serviceBaseType.GetMethod("OnStop", BindingFlags.Instance | BindingFlags.NonPublic);
foreach (var service in servicesToRun)
{
onStopMethod.Invoke(service, null);
Console.WriteLine(service.ServiceName + " stopped.");
}
}
Now you can debug your service, set breakpoints, anything you want. When you run your application, you'll get a console window, appropriate for displaying console messages, and it will stay open until you hit a key.
I'm answering my own question here. I tried a couple of suggestions here but here's what I ended up doing...
I created a Windows Form application with a single Button and RichTextBox. This application constructed a NamedPipeServerStream on it's end. The Button's job was to send either "debug on" (command 128) or "debug off" (129) to the Windows Service. The initial value was "debug off". When the button was clicked, a command of 128 was sent to the Windows Service to turn debugging on. In the Windows Service this triggered an internal variable to be true, plus it connected to the Form application with a NamedPipeClientStream and started sending characters with a BinaryWriter as they were received or sent on the COM port. On the Form side, a BackgroundWorker was created to WaitForConnection() on the pipe. When it got a connection, a BinaryReader.ReadString() was used to read the data off of the pipe and shoot it to the RichTextBox.
I'm almost there. I'm breaking my pipe when I click the debug button again and a subsequent click doesn't correctly redo the pipe. All in all I'm happy with it. I can post any code if anyone is interested. Thanks for the responses!

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