I'm having trouble adding user controls to my project.
I right-click on my project and select Add -> User Control...
I then click Add
I drag a label onto the new user control, and save it.
I build the project, go back to my main form, and drag the control from the Components tab in the Toolbox onto the form.
I see the control, but I get an error:
Type 'crm.UserControl1' is not defined.
If I do this with a blank project, it works. I'm not familiar enough with vb.net or visual studio to understand what's going wrong.
If I double-click the error, it brings me to this line in the generated designer code for the form:
Me.UserControl11 = New crm.UserControl1()
and says that crm.UserControl1 is not defined. If I change it to Global.crm.UserControl1, it works, but obviously this code is overwritten when I fiddle with the designer.
Any ideas, or pointers to get me started in the right direction? Thanks in advance.
My main form had the same name as the root namespace. This is what caused the problem.
Kind of late to the party with this one but I had this problem and I think that the issue was due to the controls being built in a more recent framework than the one that I was using.
Basically my custom controls were built in 4.7, but my project was being built in 4.5.1
Once I changed the current build so that they both were the same it compiled happily.
As far as I know, it is kind of accessibility issue because you are able to solve the issue when you try to access the object globally. I think when you drag and drop the control, the definition codes of the control in the designer class automatically generated with private accessibility but I don't know why. You could try to change it as public. I hope this will work.
Way late to this party. I fixed it by referencing it in the aspx page with the following as it was missing.
<%# Register Src="~/Controls/mycontrolname.ascx" TagPrefix="ucControl" TagName="MyControl" %>
Related
InitializeComponent();
This code line appeared in all my Xaml pages' constructors in code behind.
It throws the following error:
InitializeComponent does not exist.
Now I cannot debug any page in my project although I have commented out this line.
How can I fix this?
Any help would be greatly appreciated.
Note: I'm using Xamarin Forms Portable project.
Update: When I comment out this line and run the pages, only an empty screen shows up in both IOS and Android although my pages were working correctly without error before.
Update 2: now the InitializeComponent lines are disappeared but the pages that I debug are still totally blank.
I have asked a question about this new problem on here.
I had also the same problem in Xamarin Forms Application.I fixed it by changing the Build Action to:
Embedded resource
for .xaml and .cs file both using property window.
Hope it may help you.
Change something in the page, then save it. Scarily this resolves the issue sometime.
If that doesn't work.
Update your nugget packages so Xam Forms is the latest.
"Clean" your project
Go to your project dir and delete the bin and obj from your projects via File Explorer.
Rebuild it.
Good luck.
Be sure that your Xaml page has property Custom Tool set to MSBuild:UpdateDesignTimeXaml
'Its not an issue. You can try to build your solution. Hopefully it will bulid perfectly. Most of the time I also get red under line on InitializeComponent(); like you same. Its a problem of Xamarin studio and Visual studio'
Is it the first XAML page you create in the project? or you created other pages and they don't contain this problem?
you can Check the comments here: http://forums.xamarin.com/discussion/17638/initializecomponent-does-not-exist/p4
Have you renamed your page? All XAML pages have a viewable partial class (the one you enter your logic code in to) and a hidden, system generated partial class.
If you renamed the class but did not use the VS rename macro, your system generated partial class no longer matches your editable partial class.
Try running 'Clean Solution' and 'Rebuild Solution' (both in the 'Build' menu) to see if VS can automatically detect and fix this for you.
If that doesn't work, make sure your pages are set as partial classes e.g. public partial class MyPage : Page
If you still have no luck, manually delete the 'obj' folder in your project's root folder, then rebuild again.
Simple trick:
Just edit your Xaml code..(Put space also enough..But need editing)
After edit the xaml page save project..
Now check error disappears..
In my case this was a result of intermediate build paths being too long for Windows. Moving my solution to just off the drive root C:\dev{solution} in my case solved the problem.
I had this problem because the namespace of my .xaml file did not match the namespace of the .xaml.cs file. Fixing the namespaces so they matched corrected the problem.
I am trying to add a simple windows form to my VB.Net project. I have used the designer to design the form how I want it with buttons, a text box and a Timer. The problem is when I try to view the code, there is only an empty class that looks like this:
Public Class MCastMain
End Class
I have set the application type to a windows form application in the project properties, and I have made a successful build of the application since doing so. I have been scrawling the internet and this forum for about half an hour now and I can't find one other person who is having this problem, nor can I find a tutorial that mentions any special steps that must be taken beyond what I have done. This is the first project I have done in Visual Studio.
I know this is probably stupid simple, but I have no idea what to do. Any help is appreciated as always.
Forms comes as partial class meaning the code is separated in two files.
The "empty" code you shown is from "mcastmain.vb" (if the file is named as the class).
With that one there is a (probably hidden) file "mcastmain.designer.vb" file which contains the generated code by the designer ; and is not meant to be modified (as any designer change will rewrite the file).
To show the hidden files you have to look in the solution explorer on the button on it's top there should be a "show all files" button. (it may be possible to do the same via the menu but I don't have VS right there to be sure where)
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 have a problem with the style of the button in a messagebox.
If I call the following line of code in a current project the button get one type of visual apperance/style. And If I create a new VB.NET Windows Application project it gets a standard Windows apperance/style.
Windows.Forms.MessageBox.Show("Yaay", "Yaay!", Windows.Forms.MessageBoxButtons.OK)
See the difference between the buttons below.
I suspect they inherit the visual apperance from it's parent or maybe from some project settings. But I have not been able to find out from where.
Both projects are created in VB.NET 2.0, and both have same System.Windows.Forms - dll as reference (c:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\System.Windows.Forms.dll).
http://www.freeimagehosting.net/uploads/2a956b0675.jpg
Screenshot can be found here.
Thanx in advance for your help!
I cannot see the image from where I am so I'm not sure if this will help you.
Open the Project Properties for each solution and look at the Application tab.
Is the "Enable Applicaton Framework" item ticked? And if so, is the "Enable XP Visual Styles" item also ticked?
That may the difference in the two solutions.
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.