I know there are a lot of problems like that and you all might think this is a duplicate but NO... this problem is different.
When I add a custom user control to a project and rebuild it, the control is added to the toolbox. If I try to add another one it does not show up in the toolbox. If I close visual studio and reopen it the first control also was removed from the toolbox and will never appear again. From now on the project is broken and no control added, remove + readded will ever show up in the toolbox. So I create a new project and it starts from the beginning.
Before this tip appears I'll say it: Automatically Populate Toolbox is True. Nothing helps against this problem. Build Project/Solution, Rebuild, Clean+Rebuild, Restart of VS, Restart of Computer, Unload and reload the project, set toolbox back to default. Nothing works.
Any ideas??
You have to remember that the designer call your code constructor and some other methods at design time.
If you build the code and the control does not appears and it has not been hidden by an attribute, then probably the code you wrote is not compatible with the designer. For example, the control might throw an exception in design mode because of incorrect code.
The attribute is [ToolboxItem(false)]. If you have a base class that hide it, it will also be hidden in derived class if not specified otherwise.
You will have the same problem if that control is used in another component. You won't see it if it does not compile and run correctly.
The trick to debug that kind of problem, is to attach a debugger from a second instance of Visual Studio to find where in your code you throw an exception.
If the control does not work at run-time, better to fix that first as if it also fix design problem, it is simpler to debug that way.
Otherwise, you have to ensure that your project dependencies are correct. The toolbox will only shows component from DLLs that are referenced by the current project (or from itself I think).
I have no clue how long this feature/option has been around but my mouse happened to pause over this button within the WPF designer early and now I'm curious what it's purpose is.
Hovering over the button, Visual Studio pops up a tooltip that says Enable project code. When I click on it, the designer seems to reload the xaml contents but I can't tell what's changed.
What does this feature do?
2020 EDIT
It's been years since I've had to work in XAML, but I've received a new project where I need to work in XAML. This feature/button seems to have disappeared. Where has it migrated?
What does this feature do?
It enables or prevents the designer from running your code in the background.
Disabling project code can lead to a loss of design time data and enabling it can lead to unhandled exceptions in the XAML designer.
These exceptions are usually caused by code that attempts to access properties or methods which work differently when your application is running in the designer compared to when it runs as a built executable.
Debugging or Disabling Project Code in XAML Designer: https://msdn.microsoft.com/en-us/library/mt622752.aspx?f=255&MSPPError=-2147217396
I'm not certain why, but the drag drop events on an HwndHost don't seem to work (actually no events seem to work at all). I am able to hook into the windows messages going to the HwndHost, however, I can't seem to find anything of use.
I am trying to be able to drag a node from a tree-view onto an HwndHost that is hosting XNA. I set AllowDrop to true on the HwndHost, but it appears to do nothing. Does anyone know how I can enable to HwndHost to be a target of a drag/drop operation?
Thanks!
Is this behavior only when running under the debugger?
Are you running Visual Studio as administrator?
If so I recently ran into this problem. Try it without debugging, if that works you'll need to run the app then attach to it to debug the drag and drop code.
It's a security feature in Windows :/
Is there any way to force the WPF designer to reload or refresh, without rebuilding the entire project or solution?
If there's an error, I get an option in the designer view to refresh the designer. But if I don't have an error, how can I get the designer to refresh after I've made a change?
I'm a little late but this is the best solution1 I've found so far: whenever the designer does stupid stuff, I just kill it's process.
Press Ctrl+Shift+Esc
Navigate to the Processes tab.
Kill XDesProc.exe
This also fixes issues for the properties window (like when it gets jammed and you can't type stuff into it).
1 This is a solution for designer issues. Your issues may also be caused by compilation problems, in which case just right click on the solution in the solution explorer, and clean it. The reason behind it is that sometimes the compilation loses synchronicity with the generated files from XAML, and cleaning the solution just deletes those intermediate files; it's like a reset so your compilation can start off with a clean slate.
To do it fast:
Comfortably it's usually the last one if sorted alphabetically.
When it is, it's almost like a ritual for me to quickly pop up the task manager, click any process, press End, Delete, Enter (done), Esc (exit task manager). Instead of restarting VS and waiting for all the loads & unloads, you can do that in 1-2 seconds.
In newer versions of Visual Studio there is an icon on the bottom of the designer to "Disable Project code". If you toggle this off and on it will reload the designer.
You can add this to the Tools menu in Visual Studio.
Once configured, use Tools..XAML Designer Restart:
Alt+T then L
I tried configuring it for Alt+T then X but this clashed with Tools..Choose ToolboX Items.
Update
These days, I prefer to just hit Ctrl+Shift+Esc to bring up the process manager, then X to skip to XDesProc.exe then Delete to kill the rogue process(es).
The Visual Studio designer attempts to keep the rendered view in sync with the XAML. That's the advertised behavior.
The first thing you should check is that there are no errors in the errors window. It may be something as simple as a missing angle bracket.
The second thing to check is whether you have any code (other than your code-behind) which needs to be compiled for the designer to render your XAML correctly. This includes any of your own datatypes that you instantiate in XAML, any custom controls you have written (e.g. MyTextBlock derived from TextBlock), or any classes directly or indirectly in support of design-time data. If so, you need to rebuild your project.
The last thing to check for is possible bugs in the designer. In spite of the advertised behavior, the designer may get out-of-sync due to bugs. In that close, close the XAML window and re-open it. Other tricks that might work are selecting the XAML tab and then the Design tab, or maximizing the XAML pane.
As far as rebuilding your application goes, you don't need to do this as a habit. You only need to recompile it when the above conditions apply. Once they don't apply, you can just edit the XAML. Another way to say this is that if you haven't modified code, you shouldn't need to rebuild (modulo bugs).
I'm not sure, but I think a build will refresh your view in that situation.
There is any event handled in that XAML file, then mostly it will not display the design preview from Visual Studio. If you want to see the design from Visual Studio, try with Command Binding instead of event, you will see the preview.
I'm not sure how this works in WPF editing, but with ASP.NET pages when the design view wont update i can do 2 things
Exit Visual Studio and restart
Go into source view (not split), type something and remove it (not by undoing, just delete or backspare) and save it. Then return to design view, usually the view has been updated then.
When you add a new row of code or a new object, XAML designer is sync but I encountered non-sync behavior when a property of an object is changed.
A tricky way is that when you change a property you only need to remove a ">" character from end of an instruction then retype it.
On the toolbar in the XAML designer, choose the "Disable project code" button to reload the designer link which stays on the right side of "Turn on snapping to snaplines".
Disable project code in the designer
If it is disabled, you can try to check the configuration manager and change processors to "Any CPU".
For projects that target ARM or X64 processors, Visual Studio cannot run project code in the designer, so the Disable project code button is disabled in the designer. Check this:
Debug or disable project code in XAML Designer
For information, I had the same issue with the XAML Designer of Visual Studio Community 2017, i.e. sometimes the designer doesn't show anything, the easiest solution is then to close the XAML file and reopen it.
I also frequently get the exception "An Unhandled Exception has occurred - Click here to reload the designer - Details: The XAML Designer has exited unexpectedly" (the click restarts the designer successfully).
Note that, in this VS version, the process of the XAML designer is not named XDesProc.exe, but UwpSurface.exe. If you prefer or have to kill the process, then the designer shows the same exception as above, and you may restart it.
use process hacker and kill the WpfSurface process (blend only)
Update for designer refresh/reload Visual Studio 2022 Xamarin, taskkill /IM java.exe
I want to create control that seems and works like the Solution Explorer of Visual Studio.
I mean not the functionality of solution explorer, the control should be seems like that control. That means, server explorer, toolbox, error List,... All these controls will pop-out when we put mouse and pop-in when we leave. We can lock and unlock those controls also.
So can anyone help me, to get the solution for this problem.
Thanks!!!!!!!!!!!
I am assuming you are using C#/VB.NET for development. The dockpanel suite will provide a docking framework for an application. Basically in terms of dockpanel, it is the forms which can be docked on the application using drag and drop like visual studio.
So create a treeview control in the form and dock it to the parent. You can populate the treeview control based on file directories or any specific needs of your project. Please note in dockpanel you create a form by not inheriting from Form class but from DockContent class. Documentation will give you more insight of how to create applications. It has a good example along with the source code in which it simulates the all the visual studio panes. It also provides and option to save the position of various docks which can act as a user preference. For eg, you may like to position solution explorer on left side whereas i may want it on right side. this get stored in a conf file which gets read next time when you start the application.
Incase you using MFC, then visual studio 2008 SP1 provides you with docking framwork and within that use the treeview control.
XAML also provides a docking framework. But i am not sure, you need to verify.
Win32 API does not have any native docking framework.