Error using UseSystemPasswordChar = true

Question

1.00/5 (2 votes)

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Hello,

I have the following code for a password box and when the user clicks it, I'd like for the text "Password" to be removed and a password character to be used.

VB

Private Sub TextBox2_GotFocus(sender As Object, e As EventArgs) Handles TextBox2.GotFocus
       With TextBox2
           If .Text = "Password" Then
               .Text = Nothing
               .ForeColor = Color.Black
               .UseSystemPasswordChar = True
           End If
       End With
   End Sub

Whenever I click textbox2, I get the error

An unhandled exception of type 'System.ComponentModel.Win32Exception' occurred in System.Windows.Forms.dll

Additional information: Error creating window handle.

on the line

VB

.UseSystePasswordChar = True

I have no idea why this is happening as I've never encountered it before.
How can I make this work?

-Rixterz

Posted 3-Nov-14 12:16pm

Rixterz123

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Comments

Sergey Alexandrovich Kryukov 3-Nov-14 18:28pm

This is not related to password. You are not showing the offending code. Most likely, your method is used as an event handler for the event GetFocus, not Click.
You need to provide exact exception information, including the line of code. Look, you already asked so many questions and keep getting a lot of criticism related to the quality of your question. Can you finally learn the lessons and provide comprehensive information?
—SA

[no name] 4-Nov-14 10:40am

If by "offensive" you meant that I'm making spyware or such, this is the code for the form which is a login screen. Somehow I can't see anything wrong with this:
Public Class Form1
Private Sub TextBox1_GotFocus(sender As Object, e As EventArgs) Handles TextBox1.GotFocus
With TextBox1
If .Text = "Username" Then
.Text = Nothing
.ForeColor = Color.Black
End If
End With
End Sub
Private Sub TextBox1_LostFocus(sender As Object, e As EventArgs) Handles TextBox1.LostFocus
With TextBox1
If .Text.Replace(" ", Nothing) = Nothing Then
.Text = "Username"
.ForeColor = Color.Gray
End If
End With
End Sub
Private Sub TextBox2_GotFocus(sender As Object, e As EventArgs) Handles TextBox2.GotFocus
With TextBox2
If .Text = "Password" Then
.Text = Nothing
.ForeColor = Color.Black
.UseSystemPasswordChar = True
End If
End With
End Sub
Private Sub TextBox2_LostFocus(sender As Object, e As EventArgs) Handles TextBox2.LostFocus
With TextBox2
If .Text.Replace(" ", Nothing) = Nothing Then
.Text = "Password"
.ForeColor = Color.Gray
.UseSystemPasswordChar = False
End If
End With
End Sub
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
TextBox2.UseSystemPasswordChar = True
End Sub
End Class

Sergey Alexandrovich Kryukov 4-Nov-14 13:06pm

Gosh, no, "offensive code" simply means the piece of code which is responsible for exception throwing, has some kind of a bug, nothing else. Sorry if I confused you with this expression.
—SA

[no name] 4-Nov-14 13:06pm

I showed the line of code causing the exception but I've solved it now

Sergey Alexandrovich Kryukov 4-Nov-14 14:23pm

That's great.
—SA

[no name] 4-Nov-14 12:56pm

As for you Sergey, you're no longer welcome to comment on any of my questions as all you do is downvote and insult. You're a user of codeproject just like I am and to be honest I think you're lucky because the admins won't do anything about you due to the amount of reputation you have. Unless you own the website, you're no higher up than I am.

Sergey Alexandrovich Kryukov 4-Nov-14 13:12pm

Sorry, no. I'm not going to remember who likes my comments and who doesn't. Remember that you not more free than others. I an sorry to see so low self-esteem from you; if you really considered yourself equal (in fact, you are, of course), you would understand that we all have rights for comments. My comments are aimed to help people. The only problem is that you cannot see it. Nobody tried to offend you (again, sorry for confusing your with the expression "offensive code", but, after all, that was you who misread it).
Let's stop this discussion. Please be considerate.
—SA

[no name] 4-Nov-14 13:15pm

Just face the fact that you jumped in straight away to insult me and didn't read what I asked at all because you're asking for exactly what I wrote.
Where can you not see the offensive code? It's the third code tag. Where can you not see the exact exception information? It's the second code tag. Where can you not see the line of code? Again, it's the third code tag. Visual Studio highlighted it.

Sergey Alexandrovich Kryukov 4-Nov-14 14:24pm

No. No one insulted you. Find a single word insulting you — find a single word characterizing you personally. This is all in your head.
—SA

Dave Kreskowiak 4-Nov-14 15:02pm

Nobody insulted you. I've read through the posts a few times now and can't find where the problem is.

What I think he meant to say was "offending code", not offensive. In either case, it was a reference to the code that was throwing the exception, not a reference to you personally.

[no name] 3-Nov-14 18:51pm

What do you mean by "not related to password" and "offensive code"?
I gave you the whole exception AND the line of code. So how can you expect more that I know?
And of course it's GetFocus... It says in the method...

Sinisa Hajnal 4-Nov-14 6:14am

Try setting text to string.empty instead of nothing.

[no name] 4-Nov-14 10:39am

I'm afraid that doesn't work. But thanks for actually trying to help instead of telling me how to ask a question in an impossible way :D

Sergey Alexandrovich Kryukov 4-Nov-14 14:24pm

You are right; it hardly can make any difference.
—SA

Sinisa Hajnal 5-Nov-14 2:07am

The idea was that for some reason it really tries to use Nothing instead of empty string since the code looked correct and low level APIs sometimes behave...well...not the way you'd expect them to.

Sinisa Hajnal 5-Nov-14 2:09am

Don't take such comments personally, I voted down and commented on plenty of questions (and as far as I know, some of them could be yours, I usually don't read the names) - that just means the question needs more information. Or that the commenter rad too quickly or he was tired :)

[no name] 4-Nov-14 10:47am

I found out something interesting. I don't get any errors if I take out .UseSystemPasswordChar = False in the LostFocus event. If I leave it in, as soon as I give focus to the textbox, it flickers and shows an error. It's almost as if it's setting UseSystemPasswordChar to true and false at the same time.

[no name] 4-Nov-14 13:11pm

I gave you everything you asked for, before you even asked for it so surely if you've told me to do something and I've done it already then it's perfect and deserves 5 stars...

Sergey Alexandrovich Kryukov 4-Nov-14 13:19pm

Not yet. I'm 100% sure this code is correct is some context, so this exact exception appeared due to context of the code you show. One typical problem is doing some operations when Windows did not yet created a window handle. Besides, I have an impression that your observation is not quite correct, not sure though...
That's why I asked for more information.
—SA

[no name] 4-Nov-14 13:20pm

That's all of the information Visual Studio gave me. Although it's working now, I still don't have a clue why the error happened in the first place.

Sergey Alexandrovich Kryukov 4-Nov-14 14:28pm

As I say, it all in the context of the code you've shown. Did you output or see the exception stack? It usually shows all you need, in addition to other exception object properties. In general case, all the code related to all the points of the exception stack trace should be involved.
Most constructive approach is this: create a separate project, simplify the application to absolute minimum still allowing to reproduce the problem, and show all this code. If you focus only on one problem, this is usually possible to do.
—SA

[no name] 4-Nov-14 14:56pm

This is all of the code in the whole program so far so it was as simple as it could possible be. I'd like to say that I'm sorry that I was angry earlier; it was just because I didn't understand you that's all.

Sergey Alexandrovich Kryukov 4-Nov-14 15:40pm

I know. We're good, let's not worry about it.
—SA

Sergey Alexandrovich Kryukov 4-Nov-14 13:07pm

I explained what I meant by "offensive code", and, by "not related to password", I mean that it could have happened with any TextBox control as well.
—SA

[no name] 4-Nov-14 13:08pm

Just one grammar point: "I explained what did I mean" should be "I explained what I meant"
Hope this helps

Sergey Alexandrovich Kryukov 4-Nov-14 13:14pm

Ah, thank you very much.
This your comment is very constructive, I appreciate that, try not to miss a chance to improve/fix.
—SA

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Rixterz123 · Accepted Answer · 2014-11-04T06:52:00

Solution 2

I got it working just by looking at a line and feeling all suspicious about it. I changed the line

If .Text = "Password" Then

to

If .UseSystemPasswordChar = False Then

I have no idea why it works but it does!

Posted 4-Nov-14 6:52am

Rixterz123