today I wasted hours trying to fix the designer only showing "nothing" (one large white rectangle with gray borders), or showing some meaningless error (HRESULT failure blahblah).
After lots of trial&error I finally found out the reason:
The assembly which contains my styles / controls, etc. uses some system-dll's, like "System.Windows.Controls.Data" and "System.Windows.Controls.Data.Input" for types around DataGrid (which I use internally (among others) - sometimes as base-class, sometimes as "component").
When I reference my "Controls-Library" and try to use some control from there, the designer goes crazy with the errors described above. In the runtime however everything works flawless.
To get the designer working, I have to reference all assemblies, which my Library uses (directly or indirectly).
Why cannot the designer pick up those DLL-references from my "Bin/[Target]" folder? (They ARE there, even if not referenced - so the building system realises that these assemblies are needed directly or indirectly).
WPF doesn't suffer from the same problems btw.
Any "best practices" to work-around this problem?
Regards
Johannes
Related
I recently did some refactoring in our code and marked some widely-used functions as obsolete. The problem now is, that I get not visual indicator when I use an obsolete function right away. I have to hover over the function call to get the popup with further information about that function, and even there the "deprecated" warning is not very prominent. As these functions are to widely-used and cause no real treat, setting the isError property is not an option.
I know that somewhere I saw obsolete functions that were highlighted with some kind of underlining, but I can not find an option that does that. Where is that option, or how else can I achieve a more eye-catching indication?
I have created a simple toy VB.Net console application in MSVS, as you can see in the image the items marked obsolete are underlined in green where they are used.
If you are not seeing this then you will need to provide some more details on your solution's settings - what type of project is it, what version of visual studio are you opening it in, is it the same version it was created in, do you have any third party code linter (eg ReSharper) in use... etc
EDIT: As you mention in your comment, the project's properties, including the Code Analysis settings, will affect whether this underlining show's correctly or not; you will need to ensure the correct rule-set is selected there.
I am having a very strange situation over here.
I refered to the UWP samples and tried Custom Media transport controls sample. I ran it and it was working just fine, like its supposed to work. But then I tried and made my own project and I copied exactly everything which was in sample project not even name of file or folder was different. And then when I ran that project it gave me debugger unhandled exception and open App.ig.cs some file like this and when i continue it stop debugging. Below is the attached snapshot of that error. Any help is appreciated this is a really strange error for me as it makes no sense at all.
Note: I have tried to run it in both blend and visual studio
I solved it by simply ignoring the style of transport controls provided in the sample, for some reason that style was not able to verify some properties so I deleted that file and made my own style file, I copied the style of default media controls and edited them, it worked for me :)
My question is on how custom controls should be updated.
I downloaded this owner drawn custom control, which I built, then copied the DLL to the Debug folder of the project and loaded it into the toolbox from there.
I decided to use this button on another project. I was mildly surprised to see the control was still in the toolbox but it seemed to work just fine. I decided to change this custom button's behavior. The button in the toolbox referenced the old version number. So I deleted it and loaded the newly rebuilt DLL.
Now come the problems. The first application--the one where the DLL was added to the toolbox from--still runs okay, but the second application is throwing errors, saying, Type 'CButtonLib.CButton' is not defined. When I add the button to a form, it appears okay. I can change its properties and it shows up in the code windows and in the object browser. But as soon as I try to run it and it throws the errors, it no longer appears in the object browser. References in the code window lose their intellisense.
Things I've tried include:
Copying the DLL to the project's debug and release folders and loading them into the toolbox from there.
Removing it from the toolbox altogether and just adding a reference then copying and pasting a button directly from the first project.
Copying in a form with a CButton on it from the first project.
Scouring the internet for answers
Swearing at the computer.
Nothing seems to work and I've now spent over a day trying to solve this.
I never did get to the bottom of this. In the end I simply had to recreate the entire custom control project using a different name. I suspect the way I added the original project to the toolbox of a different program – as opposed to adding it within the test project it came with – may have had something to do with it, but that's just a guess. Anyway, I can amend and update the new control without problem now, so all's well that ends well. :-)
I'm trying to get RC of Visual Studio 2012 working for XAML files. I can't seem to get any XAML Intellisense and the option within Tools is greyed out.
I've also tried to run the solution using Blend, however I only get Intellisense for custom controls such as telerik then.
When ever I drag controls onto the design surface I get an "Object reference not set to an instance of an object" exception but the control is still added to the surface.
I've read that this was a bug within VS11 and was fixed with in the Visual Studio 2012 RC.
I've created a new Silverlight Application and the intellisense is working so i'm wondering if its an issue with how my projects are set up.
I have all of my Styles within a separate themes project, which is referenced by other all other projects. Within the designer these references show up as errors but when the application runs they are resolved fine.
Would unresolved resources at design time affect Intellisense?
Click "Build -> Clean Solution", then "Build -> Build Solution". ("Rebuild Solution" alone doesn't work.) [Source]
If you have a reference to any of the expression blend dlls for interactions and you are using silverlight5 you will need to update the following dlls:
Microsoft.Expression.Controls.dll
Microsoft.Expression.Effects.dll
Microsoft.Expression.Interactions.dll
System.Windows.Interactivity.dll
Blend + SketchFlow Preview for Microsoft Visual Studio 2012
http://www.microsoft.com/en-us/download/details.aspx?id=30702
Ref Location:
C:\Program Files (x86)\Microsoft SDKs\Expression\Blend\Silverlight\v5.0\Libraries
Exact same problem here, using WPF.
In my case, removing:
<Page.Resources>
<vm:AnyViewModel x:Key="anyViewModel" />
</Page.Resources>
Solve my problem...
One known cause of XAML Intellisense failure is if System.Windows.Controls.Toolkit is one of the project references. I've seen where deleting that reference instantly fixes the problem. The problem is described in the comments of this Connect bug for VS2012 Beta, but it applies to the RC with the July update as well.
I've found that some xaml designers for a control have this issue, where other controls are just fine.
The problem (in my case) seems to be if parameters are null or events call uninitialized singletons. Something the designer gives you a stack trace and other timers renders with no problem.
I've found by changing the back-end code for pages that don't have Intelli-sense to include DesignerProperties always fixes the issue (in my cases).
public Homing()
{
InitializeComponent();
if (DesignerProperties.GetIsInDesignMode(this))
return;
// some other code here that may have uninitialized members
}
t
I'm not sure if I had the same problem, but Intellisense mysteriously stopped working for me within a XAML file. I tried cleaning the build as someone suggested, but that didn't work.
After I restarted Visual Studio 2013, the Intellisense in the XAML page started to work again.
Failed to create component 'User Control 1'. the error message follows:
'System.NullReferenceException : Object reference not set to an instance of an object.
at System.ComponentModel.ReflectPropertyDescriptor.SetValue(Object Component, Object Value)
.............. etc..........
What should I do to fix this error?
When a User Control won't load into the Visual Studio designer here is what you need to do. These instruction are for vb.net project but c# should be similar. Also, before doing this close all open windows (or at least the source and designer files of the control you are working on.)
One last thing. The FIRST thing you should do is ensure that restarting visual studio doesn't fix the problem. If not you can try the steps that follow. These instructions assume that the errant user controls are in control library project in visual studio. If not you should be able to adjust the directions a bit to get it to work but it is much easier when the control is in its own project.
Do the following:
Make the control library your startup project.
Open the properties for the control library project and click on the debug tab.
Under Start Action click the Start external program option and browse to the Visual Studio executable.
NOTE: what this means is that when you run your solution it will fire up another instance of Visual Studio instead of actually running your solution. The First Instance of Visual Studion (INSTANCE_1) will "host" a second instance of visual studio (INSTANCE_2) when you run it.
Run your solution. INSTANCE_2 will load.
Switch back to INSTANCE_1.
In INSTANCE_1 hit CTRL-ALT-E. This will open up the exceptions dialog box. Check On the THROWN column checkbox next to Common Language Runtime Exceptions.
NOTE: This will ensure that INSTANCE_1 will BREAK at ANY runtime error even if it is hit in a try block.
Switch to INSTANCE_2. In Solution Explorer double-click to open the errant user control.
You should find that INSTANCE_1 OF Visual Studio should have stopped at the line of code that caused the designer to not load the control. Fix the code (which usually means testing for IsNot Nothing before references an object properties...but could mean other things.)
Also, sometimes I find that the control WILL load in INSTANCE_2 instead of breaking on an error in INSTANCE_1. In that case just stop debugging...close INSTANCE_2. Save/Restart INSTANCE_1 and your problem will often have gone away.
The lesson is this. User Control MUST be able to load/reference all objects and their members in order to load it into the designer. So for User Controls that will be placed onto other containers I will usually design events to notify the parent rather than trying to push objects into the child control.
Hope this helps for future reference on this old question.
Seth
Instead of the error occurring when you open up a form for editing, it sounds like this is occurring when you are already editing a form and adding new user controls. A CodeProject article that was previously mentioned shows what to do in the case of a form not loading correctly, rather than a specific user control.
Does your user control have any properties that map to custom objects (i.e. not Integer or String)? If so, the Form Designer will attempt to load your properties into the Property Editor. If showing the properties generates an error, the Form Designer will show that to you. I think this is what is happening with your user control.
If you could edit the question and add more information about the nature of the error (more of the error text), it would assist others in helping you better. Alternatively, see if you can find the property that might be causing the error (e.g. whether any property relies on a non-null value being set). You can also take a look at this MSDN article for tips on how to limit the control for just run-time.
Thanks, Seth, for this post! Your solution helped me nail down the error. The only thing I would add to this is that when "INSTANCE_2" loads, you may need to actually load the project file in INSTANCE_2. I needed to because I wasn't dealing with a control library, but instead had custom User Controls defined in the same project that the forms were located in. Once I loaded the project in INSTANCE_2, I opened the erring form and that caused INSTANCE_1 to pop up to the line of offending code in the User Control.
I have found that this error often occurs when control dlls are not building properly. 95% of the time this is remedied by simply restarting Visual Studio.