Found one. Bug about focus when dynamically loading controls in net

Dynamic | load | The control today writes a system framework to use the dynamic loading, when debugging discovers the program often can appear the deadlock the situation, and when the deadlock also will open a "Windowsformsparkingwindow" the background process, Ran to the internet for half a day on the Windowsformsparkingwindow of information, the results of an article in Chinese did not find, there are a few flies, to the PowerWord fee Dickens has not seen a way to. Then simply create a new project, only wrote a few lines of code, the results of the operation found that there will be a death shrink:

1. Create a new Windows application

2, add a UserControl, named UserControl1,

3, add a control in the UserControl1, any control, as long as you can get the focus of the line (Label, panel, etc.)

4. Add a method to the UserControl1.cs test:

public void Test ()
{
MessageBox.Show ("This is a test!");
}

5, in the Form1.cs to add a class-level variable: private UserControl1 curobj;

6, add a panel in the Form1, named Panel1

7, add a menu in Form1, and add two menu items, named Menuitemadd and menuitemmsg;

8, in the menu item Menuitemadd Click event to add code:

Panel1. Controls.clear ();

Curobj = new UserControl1 ();

Panel1. Controls.Add (Curobj);

9, in the menu item Menuitemmsg Click event to add code:

if (curobj!= null)

Curobj.test ();



To run the program, click Menuitemadd, Menuitemmsg, Menuitemadd, menuitemmsg; Note: Do not click Other places in the middle of these operations, found that no, after the second MessageBox dialog box popped up after the program died, With ALT + TAB, you find a list of things called "Windowsformsparkingwindow".

It was later found that the program would not die after the first click on the Menuitemmsg pop-up dialog box UserControl1 or add a control in Form1 that could be focused on, or in Panel1. Controls.Add (curobj); After adding a curobj.focus (), the problem can also be solved, I think it should be in the second dynamic loading because of the first Panel1 object destroyed, the form also has no focus, after the second pop-up dialog box, The system cannot find the focus of the currently active form, so the program will die, and it will not be a problem when we click the mouse or place it in the program.

Think about it, although the problem is solved, I always feel that although I am writing the program should indeed be in the dynamic loading object after the focus, but even if I missed,. NET again how to say also should not do nothing to let system die and get a baffling windowsformsparkingwindow? Should you at least help me fix it or throw an exception? I think it's kind of. NET bug, has been fed back to Microsoft, see http://www.mscommunity.com/communitywish/ViewWish.aspx?WishID=25990, hope that the next version of Microsoft will be able to get rid of it.