System Dialogs Not Showing

Question

1.00/5 (1 vote)

See more:

Windows 7 (x64, but the app is x86) (And two different machines.)

Whenever I use a built-in dialog (or MessageBox, for that matter) is does not appear.

I've tried both .ShowDialog() and .ShowDialog(this) to no avail.

BUT, if I briefly tap the ALT key after the dialog is supposed to show up, it magically appears. Likewise if I open, close, move any other application that's available. For instance, IE or Chrome. It's like the system is waiting until something else happens before showing the dialog.

I've eliminated the use of MessageBox by making my own, so that's not a problem anymore... But I don't have an alternative to the FolderBrowserDialog.

What the heck is going on? Any ideas?

Posted 14-Oct-13 5:44am

GenJerDan

Updated 14-Oct-13 5:48am

v2

Add a Solution

Comments

OriginalGriff 14-Oct-13 12:02pm

Have you checked your threading?
I've had odd effects when trying to show dialogs from non-UI threads (but mostly you get a "bad thread" exception)

GenJerDan 14-Oct-13 16:02pm

What it is doing is main form "Form A" opens "Form B" modally, which pops up the FolderBrowserDialog modally when a button is pushed. I have not explicitly created any threads. Is Windows/VS doing it behind my back?

pasztorpisti 14-Oct-13 16:56pm

Does the dialog have a parent wnd?

GenJerDan 14-Oct-13 20:32pm

Yes. Tried with and without. No difference.

OriginalGriff 15-Oct-13 3:52am

Don't think so.
I just tried your system in my code:
Main form has a button, which uses ShowDialog to show a Modal form of my design.
On that form there is a button, which opens a FolderBrowserDialog via ShowDialog.
It works fine in an x86 app on Win7/64 for me, without any threading (with threading I get a
"Current thread must be set to single thread apartment (STA) mode before OLE calls can be made. Ensure that your Main function has STAThreadAttribute marked on it. This exception is only raised if a debugger is attached to the process." exception in the debugger).
What are you doing that is different?

GenJerDan 15-Oct-13 11:11am

Not a dang thing. I've been "skinning" the forms, but took the skin off the one calling the dialog, but it made no difference.. I'll try de-skinning everything and see if there's something in there doing it. Have never gotten an error (at least that would point to where the problem is). Oh, and it happens with or without debugging, and inside or outside VS. I always seem to get the weird problems...

OriginalGriff 15-Oct-13 11:19am

Have you tried creating a new project, adding your forms, and the hacking out everything until the problem goes away?
I find it can help with the really odd ones! :laugh:

GenJerDan 15-Oct-13 11:23am

Except for the pretty forms, it's a simple database app. I'll just set everything back to "Form" instead of the custom class first. If that doesn't do it, I'll grab the machete and start trimming... :p

Sergey Alexandrovich Kryukov 14-Oct-13 17:05pm

First of all, if you right "MessageBox", the question is: which one? Full type name, please.
And no one will tell you what's going on unless you present a highly simplified but comprehensive code sample manifesting this problem. There are too many ways to screw up things...
—SA

GenJerDan 14-Oct-13 20:32pm

How do you screw up a MessageBox?
if (MessageBox.Show("Really delete this entry?", "Confirm delete", MessageBoxButtons.YesNo) == DialogResult.Yes)
{ etc.

That's System.Windows.Forms.MessageBox

Now that one, I didn't include the owner.

But for the FolderBrowserDialog, I did.

But there's not much to show, code-wise. I dropped the dialog on the form, not created in code, so all I'm doing is:

if (dlgFolders.ShowDialog(this) == DialogResult.OK)
{etc.

And it behaves the same whether or not there's a "this" in there.

I guess all this means is no else has ever seen this before. Googling shows other people...who fixed it by including the owner. Made no difference on mine.

Sergey Alexandrovich Kryukov 14-Oct-13 20:39pm

You should ask yourself how it can be screwed up, as this is really an unusual thing, indeed. If I write it, it will work, for sure. Can you write only this line of code in your entry-point method ("Main") and nothing else, nothing at all? It should show the dialog. If not, something has broken in your system. I still suspect that something else is written in your code, something weird. That's way I asked you to write a comprehensive code sample, 100% complete source code...
—SA

GenJerDan 15-Oct-13 11:13am

Not just my system, though, so it has to be the code. I'll go in and cut out all the "extra" stuff and see what happens. It's probably going to end up being the code uswed to pretty-fy the forms. That'll teach me to go to CodePlex for things.

Sergey Alexandrovich Kryukov 15-Oct-13 11:34am

:-)

1 solution

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

GenJerDan · Accepted Answer · 2013-10-15T06:33:00

OK. Weird problem, weird solution.

The menu on the main form had a custom renderer:

private class MyRenderer : ToolStripProfessionalRenderer
{
protected override void OnRenderMenuItemBackground(ToolStripItemRenderEventArgs e)
{
if (!e.Item.Selected)
{
base.OnRenderMenuItemBackground(e);
e.Item.ForeColor = Color.White;
e.Item.BackgroundImage = AMSIOS.Properties.Resources.BGTile;
}
else
{
e.Item.ForeColor = Color.Black;
e.Item.BackgroundImage = AMSIOS.Properties.Resources.BG;
Rectangle rc = new Rectangle(Point.Empty, e.Item.Size);
e.Graphics.FillRectangle(Brushes.DarkGray, rc);
e.Graphics.DrawRectangle(Pens.White, 1, 0, rc.Width - 2, rc.Height - 1);
}
}
}

Tracing through the execution (F11, rather than F10) and I saw the main menu was being redrawn and redrawn and redrawn for no apparent reason. The main form isn't even accessible at that point, so why was it rerendering it? Now I just have to figure out why that (stolen) code caused the dialog box problems.

Thanks, all.