问题
I've inherited a project that has been modified in a way that is beyond me to undo. Every single control on the form is not modifiable in the designer except through the Properties window and each control has an icon in the area below (see image) in the section usually reserved for non-visible items (e.g. DataSource). How do I undo this and return the designer to a usable version without wiping it all out and starting over?
回答1:
Could the controls be locked? I have run into legacy code in which the programmers have locked every single control, meaning you cannot move or resize them in the designer. If so, select them all and change the Locked property to false (you should also see a padlock in the designer when you select them, if they are locked.
If not, well maybe you can create a new dialog/form and copy the controls unto it and see if that clears things up. Another trick could be to add a second instance of the user control(s) to see if the newly added control works as expected. If so, go through the code and point all events/logic to the new control (tedious yes, but may work).
Also, you can never edit individual sub-controls of a user control in the designer for the form/control where you instantiated the user control. You must go to the designer of the user control to edit individual (sub)controls of a user control.
回答2:
If the Infragistics controls are shown in the Component Tray, than there might be version differences. What you could try is to open the licenses.licx file and remove the content from there. Do you have an Infragistics controls installed on your machine? Are there any difference after setting the "Specific Version" property of the Infragistics assemblies to "false"?
Is this happening only in your existing project or the same behavior is reproducible in a new project as well?
回答3:
You have to load the dll that contains the controls you can't modify in the designer.
the steps are:
right click in the ToolBox in visual studio designer (on General for example).
select Choose Items...
after a while vs load items press browse and select the dll interested than the componet should appear in the grid. Do this for all the dll that contains the controls you are interested.
-Make sure you have checked the component (use filter text box if you have a lot of component loaded).
press ok.
Now you should be able to move controls in designer.
回答4:
I have also seen behavior this when a user control or form is incorrectly flagged as a 'Component'.
Some manual hacking of the .csproj file may be the answer then. Open the project file in a text editor, and find the references to your control. If you find a subtype defined as:
<Compile Include="MyControl.cs">
<SubType>Component</SubType>
</Compile>
The forms designer will interpret it as such. You can change the 'SubType' to 'UserControl' to fix it.
来源：https://stackoverflow.com/questions/14342720/controls-on-winform-not-modifiable-in-designer