For background, I am currently writing an OpenTK app that should show a message box if an error occurs. Usually on Windows-only apps this is easily done with Winforms, but I would like this to work on not just Windows, but Linux and Mac as well. So far, my search for potential solutions has not turned up anything useful to my use case.
I'd prefer to stay away from full UI libraries if possible as to make my app as light as possible. I just want it to use the system-native message box.
Are there any existing libraries that can do this? If there aren't, then how could I go about writing my own implementation, if possible?
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I'm going to develop a desktop application which is a sort of background service listening for events. The requirements for this application are:
tray icon in background always visible
show up notifications on desktop when an event occurs (like receive an email such as, you will notify with a popup)
The main problem is that the application must run under Windows,Mac and Linux.
I decided to develop the main business logic in .NET Core, but I have a few problems about the front-end part; using Windows.Forms.NotifyIcon it's easy, but obviously this solution isn't valid for other platforms.
So, I found GtkSharp project, in particular the StatusIcon object seems to do exactly what I need, except for the notification part. What I need is a sort of balloon info which is already part of Windows.Forms.NotifyIcon, but not in Gtk. Does anyone know if there is a library or a component that allow me to achieve my requirements for a cross-platform context?
[UPDATE]
I asked directly in GtkSharp channel and they told me that is not possible do what I need with GtkSharp (moreover StatusIcon is deprecated and removed from GTK 4).
I found another interesting possible way, seems that Electron framework support all my requirements. Is a different approch, but it covers all what I need and works well on MacOs,Windows and Linux.
I am doing a desktop application for calendars,sticky notes,diary,todolist,reminders and sending and receiving e-mail. I want to make a widget for all this.Wiget should also display messages if new mail is received. but i dont know from where to start making a widget.let me know is there are some controls in visual studio to make widgets or not.From where is should start.
You're looking for WPF. It's a steep learning curve, but you'll be able to virtually make any app you want. It supports real transparency, you can design the app the way you want without borders. You're looking for Window.WindowStyle = WindowStyle.None. Start from here.
Note that it won't be a 'widget' as the clock widget in Windows 7 for example. You'll make a normal desktop app (.exe) but with special functionality.
Bottom line, you can do that (and more) in WPF but you'll want to be comfortable around it first.
I'm writing a small c# program, I don't want the final user to take screenshots while using my program, is it possible? Or even if he takes one, how can I know it?
Thanks in advance and sorry if this is a poor-content question due to my lack of experience in c# coding.
You can create a system-wide keyboard hook using the low-level keyboard filter and cancel any printscreen keyboard combination. But if someone has also installed a helper application (like Gadwin or something) it'll become a lot more difficult because you won't know beforehand what keyboard shortcut you should catch (most tools allow to specify your own hooks).
Here's an article on using hooks in C#
and here's a ready-made keyboard hook library for .net that uses global mouse and keyboard hooks (use Google to find more freeware and commercial libraries and tools).
On a side note: it's generally not preferred to change the system behavior. Screenshots are system behavior and serve a distinguished purpose for trouble shooting. If you prevent this, users will not be able to show you a screenshot of something wrong. But if you must do it, you can do it.
EDIT: on a deeper level, you can install an API hook. All screenshot applications use API calls to get the content of a (part of) the screen. But API hooks are hard to get right. A more trivial way is probably by writing a user-level driver. While you can prevent all this, it is really worth all the trouble?
You might want a keyboard hook. But it'll tell you if the user pressed the "print screen" key, not if someone programmatically take a screenshot using some GDI function.
I doubt it's possible to prevent all the ways of taking a screenshot.
General answer: No. It's not possible to detect this - especially from C#. There are dozens of ways to take screenshot and even applications written in C++/WinAPI can only detect some of them, but not all.
Also consider - what if user is running your app in virtual machine? He'll be able to take screenshots at host machine and you can do absolutely nothing to detect (not even prevent) this.
While talking with a friend over yahoo messenger, I told him would be really cool to make a bot to answer with generic messages when someone starts a conversation. Upon thinking about what I told him, I realized it would be quite interesting to do something like that. The problem is that I don't know much about win32.
So my question is this: how do you 'link' a process to both another one and the windows environment? The goal would be to have an application running in the background which makes some sort of a query to see what windows are opened and when a new yahoo messenger conversation window appears it should send a list of keystroke events to that window.
I could use either C# or VC++ for the programming part and I can use any help: either specific answers or tips that could help me - e.g.: what to google for. So far my google research only came up with some apps/dlls/code that do that for you and some scripting stuff and I'm not exactly searching for that. I want to do all the work myself so I can learn from it.
It seems like you basically want to control other applications.
There are roughly 2 ways to do this on windows
1 - Use the low level windows API to blindly fire keyboard and mouse events at your target application.
The basic way this works is using the Win32 SendInput method, but there's a ton of other work you have to do to find window handles, etc, etc
2 - Use a higher level UI automation API to interact with the application in a more structured manner.
The best (well, newest anyway) way to do this is using the Microsoft UI Automation API which shipped in windows vista and 7 (it's available on XP as well). Here's the MSDN starter page for it.
We use the microsoft UI automation API at my job for automated UI testing of our apps, and it's not too bad. Beware though, that no matter how you chose to solve this problem, it is fraught with peril, and whether or not it works at all depends on the target application.
Good luck
Not quite the same domain as what you're looking for, BUT this series of blog posts will tell you what you need to know (and some other cool stuff).
http://www.codingthewheel.com/archives/how-i-built-a-working-poker-bot
If you really want to learn everything from scratch, then you should use C++ and native WIN32 API functions.
If you want to play a bit with C#, then you should look the pinvoke.net site and Managed Windows API project.
What you'll surely need is the Spy++ tool.
http://pinvoke.net/ seems to be the website you are looking for. The site explains how to use Windows API functions in higher level languages. Search on pinvoke for any of the functions I've listed below and it gives you the code necessary to be able to use these functions in your application.
You'll likely want to use the FindWindow function to find the window in which you're interested.
You'll need the process ID, so use GetWindowThreadProcessId to grab it.
Next, you'll need to use OpenProcess allow for reading of the process's memory.
Afterwards, you'll want to use ReadProcessMemory to read into the process's memory to see what happening with it.
Lastly, you'll want to use the PostMessage function to send key presses to the window handle.
Welcome to the wonderful world of Windows API programming.
Check out Autohotkey. This is the fastest way to do what you want.
I'm currently working at a application that helps people understand how to do there job. You can see it as a personal coach that guides them trough all the steps they need to do that no normal person could keep remembering.
In my previous application we had the ability to show the user up to 4 pictures (what proves to be more then enough). The application would load the data and see how many pictures where in every instruction and then sort out the picture in the best fitting way without messing up the scale and resolution of the pictures. This all was done with GDI+ and worked very well.
Ofc, change is something that always happens, my bosses came up with some great ideas. So they want to be able to see movies on the screen, animated gif's, 3D models that can rotate or animate. So I think we had pushed GDI+ to it's limits and it's time to look for something different.
I have heard and readed about WPF but have no experience with it. Is it even possible to do all what I ask in WPF? And what about the old picture-merging thing I wrote, can we also get it done in wpf? I tried to make some things working but I didn't went as smooth as I hoped.
I'm also concerned about the fact that the interface needs to be dynamic, the one moment it should be showing picture with some text above it, the other moment it should be showing another text with a video under it.
I would love to hear some opinions here and if you got some other suggestions I should look into pls tell me. Thnx in advance
PS: If WPF is the choice, should I convince my boss to change to .net 4.0?
Although my answer can be termed subjective, I find WPF better than GDI+ anyday. You can do everything you can in WPF which you have done/could do in GDI+ (apart from pure games/game engines). If you can afford the steep learning curve of WPF, I think it will be better investment as this technology is not going anywhere soon.
As for .Net 4.0, WPF 4.0 does introduces some important functions in 4.0 (specially easing functions for animations) but there is nothing you cannot do without if you are using 3.5. I won't recommend 3.0 though mainly because of performance in animations.
WPF is up to the task, but you could also check other options.
You could go web based, and have either an XBAP (WPF in the browser), or Silverlight/Flash app.
Silverlight/Flash doesn't require that much from the client (to install), and is easily updatable, and both can do the job.