[c#] How to put a UserControl into Visual Studio toolBox

I made a usercontrol in my project, and after building project, I need to put it in my toolbox, and use it as a common control. but i can't. the UserControl is in my project namespace, and I tried Choose Item in right click menu, but I didn't find a way to add it.

Recompiling did the trick for me!

I had many users controls but one refused to show in the Toolbox, even though I rebuilt the solution and it was checked in the Choose Items... dialog.

Solution:

1. From Solution Explorer I Right-Clicked the offending user control file and selected Exclude From Project
2. Rebuild the solution
3. Right-Click the user control and select Include in Project (assuming you have the Show All Files enabled in the Solution Explorer)

Note this also requires you have the AutoToolboxPopulate option enabled. As @DaveF answer suggests.

Alternate Solution: I'm not sure if this works, and I couldn't try it since I already resolved my issue, but if you unchecked the user control from the Choose Items... dialog, hit OK, then opened it back up and checked the user control. That might also work.

There are a couple of ways.

1. In your original Project, choose File|Export template
   Then select ItemTemplate and follow the wizard.

2. Move your UserControl to a separate ClassLibrary (and fix namespaces etc).
   Add a ref to the classlibrary from Projects that need it. Don't bother with the GAC or anything, just the DLL file.

I would not advice putting a UserControl in the normal ToolBox, but it can be done. See the answer from @Arseny

Using VS 2010:

Let's say you have a Windows.Forms project. You add a UserControl (say MyControl) to the project, and design it all up. Now you want to add it to your toolbox.

As soon as the project is successfully built once, it will appear in your Framework Components. Right click the Toolbox to get the context menu, select "Choose Items...", and browse to the name of your control (MyControl) under the ".NET Framework Components" tab.

Advantage over using dlls: you can edit the controls in the same project as your form, and the form will build with the new controls. However, the control will only be avilable to this project.

Note: If the control has build errors, resolve them before moving on to the containing forms, or the designer has a heart attack.

In my case, I couldn't see any of the controls in the project. Only when right clicking on toolBox and selecting "Show All" I saw them, but yet they were disabled...

Changing Project type from Windows application to ClassLibrary made the fix.

The issue with my designer was 32 vs 64 bit issue. I could add the control to tool box after following the instructions in Cannot add Controls from 64-bit Assemblies to the Toolbox or Use in Designers Within the Visual Studio IDE MS KB article.

Basic qustion if you are using generics in your base control. If yes:

lets say we have control:

public class MyComboDropDown : ComboDropDownComon<MyType>
{
    public MyComboDropDown() { }
}

MyComboDropDown will not allow to open designer on it and will be not shown in Toolbox. Why? Because base control is not already compiled - when MyComboDropDown is complied. You can modify to this:

public class MyComboDropDown : MyComboDropDownBase
{
    public MyComboDropDown() { }
}

public class MyComboDropDownBase : ComboDropDownComon<MyType>
{

}

Than after rebuild, and reset toolbox it should be able to see MyComboDropDown in designer and also in Toolbox

I found that the user control must have a parameterless constructor or it won't show up in the list. at least that was true in vs2005.

Right-click on toolbar then click on "choose item" in context menu. A dialog with registered components pops up. in this dialog click "Browse" to select your assembly with the usercontrol you want to use.

PS. This assembly should be registered before.