It sounds stupid, but this happens to me.
I activate a function, and it does its work, and after it finishes it enables itself again. With other words, the function activates twice, not once. I tried to find out why by debugging, but I didn't find the reason.
When I click on a panel this function activates:
private void Play(object sender, EventArgs e)
{
Play0(MousePositionX, MousePositionY);
if (swich_player == true && AI_enabled == true)
{
AI_playing();
swich_player = false;
}
}
The whole code is really long.
Is it me not searching correctly? Are there other reasons? In order for this function to start again, something has to activate it. I can't find what is activating the function again.
Any suggestions, where to search for the problem? Or what is the problem?
EDIT:
I finally found the problem. There is a button (button1) that changes the panel's properties, and a second button (button2) that makes the panel 0 pixels wide and 0 pixels high (in order to make it invisible). The first button also adds an EventHandler that activates the function. But button2 does not remove the EventHandler. This way the function gets called as much times as the times I have pressed button1.
Looks like what you're looking for (via your comments/edit) is the source of multiple calls to this function. With the current snippet of code, it's not possible for us to tell. But what you should do is put a breakpoint on the entry of the function and then when it is hit, look at the "Call Stack" window in visual studio.
This can be accessed via the Debug -> Windows -> Call Stack menu item (when running the program. It will not show up in Windows if you're not running)
You can then see what is calling your function through this window. It is an extremely useful tool.
Pre Edit:
Your question isn't very clear, but I think (from your variable names) that you're looking for a game loop that will continually run. If so, take a look at this blog post which has some very good information on different styles of game loops. It ranges from simple to more complex (and scalable) loops.
Your question states that you activate something once and it "enables again", and also that "In order this function to start again, something has to activate it. I can't find what". These seem to be contradictory statements. Can you edit your question to be a little clearer? If my answer is not what you were looking for after your edit, I will do my best to add whatever is needful.
check against which event you've registered this function. if you registered into to something no "OnClick" of that button, it might be the root cause
Related
I asked a question recently about how to disable the back button is Android, after a while I got it working with these lines of code
public override void OnBackPressed ()
{
// base.OnBackPressed (); /* Comment this base call to avoid calling Finish() */
// Do nothing
}
And just recently someone commented this
Disabling the back button is counter-intuitive and breaks the device
usage contract imposed by Android. So i suggest you rethink.
-Question-
What would be a possible change to this? I dont want to be able to press the back button when playing my quiz game because that would make be able to cheat. New to android Development
Instead of simply making the back button do nothing, you could have it create a popup asking something along the lines of "Are you sure you want to leave the quiz? (This will count as a loss)". And have it take the user back to the main page of your app if he confirms (instead of back to the previous page).
Why not imitate what many websites do and make it so going 'back' to a page works but doesn't display any information?
It depends on your code, but perhaps you can make your buttons and text (or whatever it is you don't want them interacting with) change to be unseen whenever they move on to a new page. Or just throw up a message that says 'You can't do that' to cover the page that they'll only ever see if they go back to view it again.
I'm building a "WPF Application" which is made to be run in the background (minimised state) and detects KeyStrokes of each and Every key on the keyboard & every Mouse Clicks.
So, my question is how to detect every keyStrokes whether app (Window) is minimised or not.
Simply, if my app is in focus then i use this code to count keystrokes.
Public int count;
protected override void OnKeyDown(System.Windows.Input.KeyEventArgs e)
{
//base.OnKeyDown(e);
count++;
tBlockCount.Text = count.ToString();
}
I just want to do the same even if my app is minimised.
I've searched a lot and come across many suggestions like..
http://www.pinvoke.net/default.aspx/user32/registerhotkey.html
http://social.msdn.microsoft.com/Forums/vstudio/en-US/87d66b1c-330c-42fe-8a40-81f82012575c/background-hotkeys-wpf?forum=wpf
Detecting input keystroke during WPF processing
Detect if any key is pressed in C# (not A, B, but any)
Most of those are indicating towards Registering HotKeys. But I'm unable to match scenario with mine.
Any kind of suggestion are most welcome.
Although I'm not really condoning the use of a keylogger (This is what you are trying to do). I would recommend taking a look at this q/a, the section near the bottom of this article, and this article for some inspiration. These should help point in the right direction for the coding side.
What you essentially need to do is just set up an event to intercept any keys that come in from the computer, then you can gather the key and do whatever you like with it (in your case, record it)
Edit: In fact, reading the third article, it actually gives a full code snippet on how to implement and use it in WPF, so I recommend just reading that one.
I have a combo box which I need to mirror in another tab page in a C# winforms based application.
I have perfectly working code for when you select a different item from the drop down list. Unfortunately, however, when I change the Text of a tab that has not been clicked on yet nothing actually happens.
If I first click each tab then everything works as expected.
Now I'm putting this down to some form of lack of initialisation happening first. So I've tried to select each tab in my constructor.
tabControlDataSource.SelectedIndex = 0;
tabControlDataSource.SelectedIndex = 1;
// etc
But this doesn't work.
I've also tried calling tabControlDataSource.SelectTab( 1 ) and still it doesn't work.
Does anyone know how I can force the tab to "initialise"?
Ok, typically I post the question after struggling for an hour and shortly afterwards find the solution.
TabPages are lazily initialised. So they don't fully initialise until they are made visible for the first time.
So i added this code to my constructor:
tabControlDataSource.TabPages[0].Show();
tabControlDataSource.TabPages[1].Show();
tabControlDataSource.TabPages[2].Show();
but this didn't work :(
It occurred to me, however, that the constructor might not be the best place. So I created an event handler for Shown as follows:
private void MainForm_Shown( object sender, EventArgs e )
{
tabControlDataSource.TabPages[0].Show();
tabControlDataSource.TabPages[1].Show();
tabControlDataSource.TabPages[2].Show();
}
And now everything is working!
Perhaps you could also use sort of a "lazy" synchronization (initialization) in this case. Quick robust ideas: polling timer to update content (which will update it once you see tab page), no dependses within second tab (no Changed events for combobox to update second tab content, use original combobox from first tab or rather have it's content underlying in accessable for both comboboxes class, etc), "reinitialization" when tab become visible (at which moment you also init your second combobox)...
Can't be a hour, no way =D
Maintaining focus across post backs is an apparently difficult task. Searching Google, you will find a ton of people that desire the same thing, but all hook it up differently, and mostly, custom-ly. I would like to avoid a custom implementation, especially if there's a way it's supported by .NET. Only after some very deep searching, did I come across PostBackOptions.TrackFocus, mentioned quietly in another stack overflow post. According to MSDN:
Gets or sets a value indicating whether the postback event should return the page to the current scroll position and return focus to the current control."
Holy crap, this is supported by .NET 4? AWESOME. But we have a ton of custom controls, how does .NET know how to set the focus on a control? I have no idea. Looking a the MSDN documentation for System.Web.UI.Control, there's an interesting method:
public virtual void Focus()
"Use the Focus method to set the initial focus of the Web page to the
control. The page will be opened in the browser with the control
selected."
Alright, clearly overridable. But what is the recommended method of doing so? It returns void. No examples. Unable to find any examples of people overriding this method in their implementations. However, after overriding it and doing nothing more than throwing an exception, it becomes evident that this is not how ASP.NET gets focus on a control that had focus before the post back: it never gets called.
After a ton of debugging using Firebug, I have found that enabling PostBackOptions.TrackFocus works! Sometimes. It is apparent that the focus of a control is only maintained when the control calls the __doPostBack JavaScript method. Other controls that launch a PostBack (when pressing enter inside the control), call WebForm_OnSubmit(), which doesn't update the ASP hidden field __LASTFOCUS. __doPostBack calls WebForm_OnSubmit() after setting the hidden fields.
This is where I'm currently stuck. It's looks as if I need to get everything to call __doPostBack, no matter what. There's very, very little documentation on the use of TrackFocus. So does anyone have any tips from here?
I've been maintaining focus accross postbacks using the method in this article:
(ie: store focus in __LASTFOCUS hidden field on field enter event clientside for all controls)
http://www.codeproject.com/KB/aspnet/MainatinFocusASPNET.aspx
If you've gotten as far as having __LASTFOCUS show up on the page, this should get you most of the rest of the way...
Note: It'd be nice to find a way to keep the extra javascript from bloating __VIEWSTATE for example.
It was working pretty well for me until I figured out that some of my pages included the hidden __LASTFOCUS field and some of my pages didn't. (That's what prompted me to search around and find your question) Now I'm just trying to figure out how to make sure __LASTFOCUS always shows up on every page I want to keep track of focus on... (Looks like I'll have to open a separate question about it)
Here is what I just did. Assuming you have a handler in your code behind that takes care of the event and has a signature like this:
protected void myEventHandler(object sender, EventArgs e)
You can use this line of code to restore focus back to the sending object:
ScriptManager.RegisterStartupScript((WebControl) sender, sender.GetType(), "RestoreFocusMethod", "document.getElementById(\"" + ((WebControl) sender).ClientID + "\").focus();", true);
just using the Focus() method of the sending control will reposition the page (if you are scrolled down a bit), but this works beautifully. And if you have specific handlers for your control, you can just use the control itself rather than casting the sender to a WebControl, like this:
protected void CityListDropDown_SelectedIndexChanged(object sender, EventArgs e)
{
...
ScriptManager.RegisterStartupScript(CityListDropDown, CityListDropDown.GetType(), "CityDropDownRefocus", "document.getElementById(\"" + CityListDropDown.ClientID + "\").focus();", true);
}
I believe the proper term is recursively. I have a Windows Form, and inside that I have a Tab Control, and inside the Tab Control are four Tabs, and inside each tab are multiple controls - Buttons, text boxes, etc. I want to change the cursor of every button to a type hand.
Below is where I have gotten so far with this inquiry:
foreach (Control c in tabControl1.Controls)
{
// The only controls that will be found here are the tabs themselves. So, now I must run a *foreach* loop through every tab found, and look if buttons are present.
}
The commented area explains my issue to some extent. I have found an example of a recurisively finding a control on a form but I am not sure why I would need to pass the contro's name as an argument as I am trying to find Every control of type button.
Here is the code that I found online:
http://www.dreamincode.net/code/snippet1663.htm
Thank you once again. I love hearing from all of you as it's an excellent learning experience for me.
Thank you very much for your time.
private void FindAll(Control myControl)
{
if (myControl is Button)
doStuff();
foreach (Control myChild in myControl.Controls)
FindAll(myChild);
}
I believe this will work. When you call it the first time, you'd pass in the form. The form isn't a button, but it will have children. Each child it has will be passed into FindAll(). If that control is a button, it will call doStuff() (you can set the cursor in there). Likewise if that control has any children, they'll be passed in.
You are correct, the term is recurisve (generally speaking, any function or sub that calls itself). So, in this example FindAll() will call FindAll() in a certain case.
Also, this is just sample code; you may want to check for null references depending on the nature of your application.
EDIT: Just as an FYI if you aren't familiar with recursion, it's pretty easy to get the dreaded StackOverflow exception. When you end up in a never-ending loop of calling yourself, you'll run out of stackspace and see the StackOverflow exception. Hence, the name www.StackOverflow.com
In this case, we don't have to worry because .NET prevents us from adding controls that create a circular reference. For example - this code will fail:
GroupBox g1 = new GroupBox();
GroupBox g2 = new GroupBox();
GroupBox g3 = new GroupBox();
g1.Controls.Add(g2);
g2.Controls.Add(g3);
g3.Controls.Add(g1);
I don't know if any of this makes sense, but hopefully it helps. Recursion is generally considered one of the 'harder' concepts to grasp for a lot of people. Then again, I'm not very good at explaining things.
You are correct that the correct term is recursion. In the link you have posted, it is indeed recursive because the function calls itself, which is a property common of recursive functions.
The function needs to take a Control instance because the function is trying to solve the problem "For a given control (which is the Control container that is passed in), find all controls inside." Notice how this method doesn't care about what 'level' the control is at, it can solve it regardless.
You are correct that if you ran the code in your example, it would not work. It would only pick up controls one level inside of the 'parent' control. This is why the function needs to call itself.
With the function calling itself, you get the following:
Call function with the outermost control.
Do I have any children?
If so, call the same function again for each child (which will again ask "Do I have any children?" on the child).
By calling the function inside the function, you will hit all levels.
WARNING: Just as a note of caution, recursion used carelessly can lead to problems. If you apply this on something that has 1000 'levels', your algorithm will take forever and possibly crash as you will run out of memory to handle it, since it is digging deeper and deeper (a stack overflow!). Separately, I suspect there is a better way to do what you are doing such that you don't need to use recursion, although it will work.
Hope this helps!