I've a WinForm that contains Navigation menu that display UserControls. Now everything works fine except the form freezes when I try to open a Devexpress UserControl from another UserControl.
Here is the code I used:
private void btnOpenUserControl2_Click(object sender, EventArgs e)
{
UserControl2 uc2 = new UserControl2(ID);
this.Parent.Controls.Add(uc2);
uc2.Dock = DockStyle.Fill;
this.Hide();
uc2.Show();
}
What could be the possible reason?
The solution to this problem is to use the GridLookupEdit control in server mode instead. In this case, the gridLookupEdit will load only a small portion of data from the database and will continue loading data when you scroll the grid. To learn how to adjust the gridLookupEdit in server mode, please refer to Server Mode topic.
the form freezes is most likely one of two things:
in your UserControl2 you hndle an event ( for example form_Load), and in that event you have an infinity loop. the other reason is you have some handeled exception, or a long flow, very long flow, that cause your program to ran slow, so slow you think it's stuck.
in anyway it be very helpful if you share your UserControl2 code. but easier will be if you just pause the program while debugging it in VS when it get stuck and see where is it stucked. from there it should be fairly easy
Related
My goal
I am working on a project in C# using Visual Studio 2013. The project is one that I intend to contain a lot of pages. These pages are all linked together using buttons. My problem is that I cannot come up with an efficient and elegant solution for this.
My attempts
So far I have came up with two potenial solutions to my problem. First I added extra forms and then on button press I hid the current form and displayed the new form, like so:
Form2 frm = new Form2();
frm.Show();`
Form1.Hide();
While this does work, I have two problems with it.
My project will end up with hundreds of forms
The transition between forms looks sloppy. I am aiming for a browser like transition by where all navigation occurs on one window, without opening and closing others.
The second potential solution I tried incorporated the use of Panels. So I essentially created each page on a different Panel. Then the appropriate panel was shown upon a button press and the rest were hidden. Like this:
private void button1_Click(object sender, EventArgs e)
{
mainMenuPanel.Hide();
submenuPanel1.Show();
submenuPanel2.Hide();
submenuPanel3.Hide();
submenuPanel4.Hide();
}
This is exactly what I was looking for however my issue with it is that managing the vast amount of panels quickly became a nightmare. Editing the controls on a Panel that was hidden behind 9 other Panels and as the number of panels in my project was only going to grow - this does not seem like the ideal solution in its current form.
In my head I thought there maybe an option in Visual Studio 2013 that allows me to 'hide' the Panels I am not using on the form, or drag them off the form temporarily. Is that an option in Visual Studio.
If not do any of you know a more efficient and manageable way of achieving this?
Thanks in advance.
If you are stuck using WinForms, your best bet is probably using UserControls. you can actually extend the UserControl class out to be a "page" ie: UserControlPage. This makes the form much simpler in function, but you will need to do some finicky work with handling events /passing data if the controls need to talk to each other.
if you aren't nailed into using Winforms, WPF supports all of this natively, and has wonderful tools for building all the pages you would need, and storing/populating your data, and propagating events.
If you want to have single form with changing content, and you don't want to mess up with panels in one form, then solution is user controls. You will be able to create them dynamically and add to form controls. Also there is no mess, because your form will be very simple - you can have single 'placeholder' control which will be used to dock user control which is currently displayed (e.g. panel control):
private void ShowContent(Control content)
{
placeHolderPanel.Controls.Clear(); // clear current content
placeHolderPanel.Controls.Add(content); // add new
content.Dock = DockStyle.Fill; // fill placeholder area
}
Usage:
private void button1_Click(object sender, EventArgs e)
{
ShowContent(new FooUserControl());
}
You could subclass the Panel class and create as many of those custom panels as needed, then they would be inserted on your Main Form, and managed as you described.
The advantage is that you would be able to individually edit them as a separate user control.
The drawback is that you lose direct event handling of controls on those panels from the main form. You can still define your own events on those panels and delegate the individual control events.
There's always a trade-off somewhere.
Cheers
I'm new into WPF and have a problem I can't seem to find a solution for.
I'm writing a G19 (Keyboard) applet. This Keyboard has a 320x240 display attached, which you can access with C#.
I'm using WPF for this, because I don't need to do any GDI drawing anymore and use the normal controls instead.
So. It works as I wish. Everything draws properly except one UserControl. I have downloaded this control -> http://marqueedriproll.codeplex.com/
In the designer, the control works, the Loaded event get's fired and the animation is good.
When I run my application, I just see the label and the text. The animation does not work, and the Loaded event does not fire anymore.
Any help is appreciated.
The main function is my wrapper. The wrapper is already a Usercontrol and displays plugins which are switchable. This wrapper has the Frame Control(Wrapper1). I replace the content of this frame every time I switch the plugin.
public void SetPlugin(IPlugin plugin)
{
if (this.MainPlugin != null)
{
this.MainPlugin.OnHide();
((UserControl)this.MainPlugin).Visibility = System.Windows.Visibility.Hidden;
}
this.MainPlugin = plugin;
((UserControl)this.MainPlugin).Visibility = System.Windows.Visibility.Visible;
this.MainPlugin.OnShow();
this.Wrapper1.Content = this.MainPlugin;
}
I think it's the right approach to handle a plugin system that way. The plugin get's drawed on my keyboard.
What I don't understand is why the usercontrol only works in the designer view and not in the running application.
The basic code of the scrolling label is so:
public MarqueeText()
{
this.Loaded += new RoutedEventHandler(MarqueeText_Loaded);
InitializeComponent();
canMain.Height = this.Height;
canMain.Width = this.Width;
}
void MarqueeText_Loaded(object sender, RoutedEventArgs e)
{
StartMarqueeing(_marqueeType);
}
I don't see a reason why it doesn't work. Actually Ive always found a way to fix a problem but this time I see nothing.
Thanks in advance. Your help is really required today.
Have a great saturday! :)
I am guessing you are rendering to a bitmap target, rather than onscreen. If you are using RenderTargetBitmap, you have a couple of responsibilities. You need to set both a presentation source, and make sure you run events on the dispatcher.
Normally, App.xaml or Application.Run does this for you, but if you are not using a Window, you are on your own.
See this related question for details.
I have a tricky problem here that I have not been able to solve and neither have the people I asked on msdn forums.
I am using a third part product (signal lab from mitov.com) which is a set of .net components.
I have created a windows form app that works fine if it is run.
I now want to show this form from another form when this other form loads (or shows, or activates...).
I already have examples of this working with another form: Here is the typical code:
I am loading a form (SecondForm) from the main program...
private void SecondForm_Load(object sender, EventArgs e)
{
Form _macros = new Macros(this); //this works perfectly fine
_macros.show(this);
//this is where I have no success
Form _spectrum = new SpectrumScope;
_spectrum.Show();
}
I get various errors from no form displayed and then an exception about not instantiating the _spectrum, to an error about cross threaded operation not being allowed, to a blue screen with a message about clocks not being synchronized between processors.
If I place a button on "Second Form" and add the show form code to the click event, it works fine.
If I try to use form.activated, or form shown instead of form.load there is not difference.
If I add a time to form Shown, which then does a button.performClick, there is no difference.
Obviously the form which contains many components (and many threads behind the scene) does not like the fact that it is not being opened by the user.
I'm fairly new to C# and I'm pretty sure this is threading related.
Thank you for any help.
Try the blow code in your form load method, that should let .Net manage the threading for you.
this.Invoke(new MethodInvoker(() => (new SpectrumScope).Show()));
Well, the problem is fixed. However, I don't really know why the issue exists.
In the spectrum form I reference static variables in the secondform. Now, I use them as follows:
string newFrequency = secondForm.frequency;
This works. However, some of these variables need to have this done:
string newBandWidth = secondForm.bandwidth.substring(2,4);
This is the command that fails. I am told I need the "new" keywork.
I changed my code provide the the string without the need to get the substring and now it all works ok.
Anybody have any ideas?
I have created a UserControl using a DevExpress XtraTreeList. Basically in this user control I am using inventory Items. which are more than 30,000. Now when I load the complete table in my typed DataSet it takes almost 6-8 seconds.
The purpose to build the usercontrol is reuseability. So that we can use it in other parts of the application.
Now I am using this UserControl in a Winform, where this usercontrol is place in the left hand side on the form where it will be used as a Menu. The user is suppose to click its desired item by expanding the nodes and when the nodes is selected and then its further details will be fetched and will be displayed in the from. So far so good.
Now the reals issue is that in the same form along with other controls, we have a Devexpress XtraButtonEdit(build using a textbox and a button on the right handside). This buttonEdit is displaying the currently selected Item(from the treeMenu UserControl) code in its textbox, when we are clicking the buttonEdit button then we are loading another form as a model and displaying the same UserControl (XTRATreeList from DevEpress). The only issue is that when I am laoding this new form as a model. The tree again takes time to load which looks bit awkward.
To rectifiy this issue, I am trying to implement the Background worker thread, but bit confused that where should I implement that backgroundWork. In the User Control or in the form.
If I implement that Background worder in the UserControl then how can I access this BackgroundWorker thread and execute it on the main Form where I am using the UserControl on the left hand side as a Menu. Actually what I want is when user clicks the ButtonEdit control and the form loads, it should load like a flash or max in 2 sec....please help.... and execute it.
I hope that ppl will understand my issue.
If somebody finds any difficulty plz let me know....
Regards,
You don't have to "access this BackgroundWorker thread and execute it on the main Form".
A user control could contain its own Bgw. You nee a synchronous method (on the UC) to start it. Then handle the completed (and mayb progress) events inside your UC.
But the data won't load any faster, you only unfreeze your main GUI.
If the delay is caused in the code that loads the tree, then you should "thread" that part. I would recommend reading this sample chapter from C# in a Nutshell: http://www.albahari.com/threading/. They cover C# 4.0, but you should be able to apply most of the concepts to C# 3.0 if that's what you are using.
I have textbox inside a usercontrol and I add the usercontrol to the MainWindow with the following XAML:
<Views:MyUserControl />
I have one TextBox in MyUserControl, the problem is that the TextBox doesn't take any input. Backspace och space works, but if I press the letter och numbers no text is added to the TextBox.
I have made sure that the text is not just hidden in the TextBox.
I have also tried to add a RichTextBox to MyUserControl with the same result, it doens't take any input (beside space och backspace).
I have also tried to add a TextBox to the MainWindow with the same result; it doens't take any input (beside space och backspace).
Also MyUserControl is added in a TabControl and TabItem.
Any clues?
Edit: Additional information
Forgot to write that I'm opening/creating the WPF Window from a WinForm application.
When I set my startup project in VS10 to be my WPF-project it work great with the keyboard input to the TextBox.
How come?
Im opening/creating my WPF windows with the following code:
MyWpfProject.MainWindow mw = new MyWpfProject.MainWindow();
mw.Show();
Edit: Solution
So I guess my real problem was that is was opening the WPf project from a WinForms application.
I added the following code:
MyWpfProject.MainWindow mw = new MyWpfProject.MainWindow();
ElementHost.EnableModelessKeyboardInterop(mw);
mw.Show();
"The EnableModelessKeyboardInterop() call is necessary to handle keyboard input in the WPF window if loaded from a non-WPF host like WinForms."
http://weblogs.asp.net/jdanforth/archive/2008/07/29/open-a-wpf-window-from-winforms.aspx
Answer to my own question (if someone else run into the same problem):
If you open a WPF-form from a WinForms application you have to do the following to get keyboard input:
MyWpfProject.MainWindow mw = new MyWpfProject.MainWindow();
ElementHost.EnableModelessKeyboardInterop(mw);
mw.Show();
"The EnableModelessKeyboardInterop() call is necessary to handle keyboard input in the WPF window if loaded from a non-WPF host like WinForms." http://weblogs.asp.net/jdanforth/archive/2008/07/29/open-a-wpf-window-from-winforms.aspx
maybe your user control is getting the keyboard event instead of your textbox? try to search in this way, it happens with mouse buttons.
I had the same problem but my Environment was built such that I could not apply the solution above. As it turned out that wasn't the problem. It was much more easier than expected.
I host a WPF User Control inside WinForms. My WinForms MainView (Startup form) did override the "ProcessCmdKey". Because of logical errors it returned nothing.
Nevertheless I received all key events in code behind in my XAML file but this events never updated the "Text" of my text box. Only space and backwards did so and this were the key events I didn't receive in code behind.
So in case you don't think of the simplest solution here it is for VB.NET.
STRG+F "ProcessCmdKey" and make sure that you Return the correct value of you may completely uncomment it just to verify that it isn't causing you the same trouble as it did to me.
I would like to add my own answer just on the off chance it can help anyone else with the same or similar problems. My particular use case was a .Net windows form created by an addin. The addin was running out of Autodesk Inventor which I think may be WPF (but don't take my word for it.) The addin had several windows forms some docked within the application and with some acting as popups or a separate secondary window. The solution was to set the windows forms owner to one of the docked forms. Doing this allowed text to be edited and entered into its textboxes. Very niche solution to a niche problem but hopefully it may help someone at some point in the future.
private void CreatePanels(DockableWindows DockableWindows)
{
//Create the dockable window that the panel form will live on.
DockableWindow SideWindow =
DockableWindows.Add(SidePanelNames.GUID, SidePanelNames.InternalWindowName, SidePanelNames.Title);
//Configure the windows settings.
SideWindow.ShowTitleBar = true;
SideWindow.ShowVisibilityCheckBox = true;
SideWindow.DisableCloseButton = false;
SideWindow.Visible = true;
SideWindow.AddChild(SidePanel.Handle); //Add the forms as children and then display to the user.
SidePanel.Show(); //Display the panel to the user.
}
/// <summary>
/// Creates the Display window were order and patient information is displayed to the user.
/// This method makes the adjust device form the owner of the display window. Because of this
/// dependecency it should be run after the panels have been created.
/// </summary>
private void CreateDisplayWindow()
{
DisplayForm = new DisplayForm //Create the display form.
{
Owner = SidePanel //Doing this allows text boxes to have values entered into them.
};
DisplayForm.Show(); //Show the display form to the user.
}
//Adding the side side panel as the owner of the display form was effectively the only change I needed to make.
I will add a few words of warning for anyone attempting this solution. Simply put I've since found out it's not great. It prevents the form or any of its controls from detecting certain key presses (enter and tab) which matters a lot for my usage. You'll find a much better and solution here https://forums.autodesk.com/t5/inventor-forum/dockable-window-with-wpf-controls-don-t-receive-keyboard-input/td-p/9115997