[VS2008 - Compact Framework] How to prevent a closed form from been disposed - C# Discussion Boards

Re: Upload encrypted excel file to datagridview

29-Sep-19 23:06

At time of posting, there are 14,311,184 members at CP. Do you really want all of them to help? Smile | :)

Seriously though, you need to elaborate what help you are looking for.

"It is easy to decipher extraterrestrial signals after deciphering Javascript and VB6 themselves.", ISanti[^]

OriginalGriff30-Sep-19 1:30

OriginalGriff

30-Sep-19 1:30

There is nowhere near enough information here for us to begin to help you - we have no idea what this " software that used to encryte excel file" is, what encryption method(s) it uses, how you use it, or how you propose to use it.

We don't even have any idea where you are stuck, or what help you might need - and that's kinda important, don't you think?

Start here: Asking questions is a skill[^] and think about what you need to know, and what you need to tell us in order to get help.

Sent from my Amstrad PC 1640
Never throw anything away, Griff
Bad command or file name. Bad, bad command! Sit! Stay! Staaaay...
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Could Not Decrease right of Non Client in Edit Control

Member 1180360726-Sep-19 6:33

Member 11803607

26-Sep-19 6:33

In Subclassing the edit control wparam in wm_nccalcsize return 1 only not 0 , and give me rgrc0 or rgrc1 bottom or right Zero so cannot decrease right of non client area and draw edge , before subclassing the Edit Control i used swp_framechanged in SetWindowpos to draw new style

Re: Could Not Decrease right of Non Client in Edit Control

Richard MacCutchan26-Sep-19 6:42

Richard MacCutchan

26-Sep-19 6:42

You already posted this in the C/C++/MFC forum. Please do not repost.

Re: Could Not Decrease right of Non Client in Edit Control

Dave Kreskowiak26-Sep-19 10:23

Dave Kreskowiak

26-Sep-19 10:23

This doesn't appear to have anything to do with C#.

Asking questions is a skill
CodeProject Forum Guidelines
Google: C# How to debug code
Seriously, go read these articles.

Dave Kreskowiak

Re: Could Not Decrease right of Non Client in Edit Control

Member 1180360726-Sep-19 21:54

Member 11803607

26-Sep-19 21:54

This is a clear question if somebody know api function can answer my problem , how programmer draw rectangle in edit control ? we have to reduce the client width then put rectangle .. now why can not set rgrc0

Re: Could Not Decrease right of Non Client in Edit Control

OriginalGriff26-Sep-19 23:38

OriginalGriff

26-Sep-19 23:38

It's not that clear - even in the right forum - but as a C++ question in a C# forum? It's not relevant, and thus not a "good question".

You have it posted in the right place: "scatter shot" posting it in irrelevant places doesn't improve your chances of an answer, it reduces them - because it wastes our time, and does not inspire me to go near the right place to answer it.

In essence: it's childish "attention getting" behavior and from an adult who should know better by now, that's rude.

Sent from my Amstrad PC 1640
Never throw anything away, Griff
Bad command or file name. Bad, bad command! Sit! Stay! Staaaay...
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[VS2008 - Compact Framework] How to prevent a closed form from been disposed

steve_949661326-Sep-19 5:03

Re: [VS2008 - Compact Framework] How to prevent a closed form from been disposed

26-Sep-19 5:03

Hello everybody.

My application runs in Windows Embedded Compact 7,is written in C# and it uses .NET Compact Framework 3.5.

In the application there is a form, I call it FormMain, two UserControlls, Page01_UC and SetupHome_UC, another form, FormDateTime.

In FormMain i declared:

public static Page01_UC uc1 = new Page01_UC();
public static SetupHome_UC uc2 = new SetupHome_UC();
public static FormDateTime uc3 = new FormDateTime();

In the FormMain load event:

uc1.Parent = this;
uc1.Location = new Point(0, 0);
uc1.Page02_UC_Load(); //something to do at startup
uc1.Show();

In the uc1 UserControl there is a checkbox used to show SetupHome_UC:

private void SetupCB_CheckStateChanged(object sender, EventArgs e)
{
  if (SetupCB.Checked)
  {
    FormMain.uc1.Hide();
    FormMain.uc2.Parent = FormMainRef; //reference to FormMain
    FormMain.uc2.Location = new Point(0, 0);
    FormMain.uc2.Page02_UC_Load(); //something to do at startup
    FormMain.uc2.Show();

    SetupCB.Checked = false;
  }
}

In uc2 UserControl ther is a button to show FormDateTime:

private void DateTimeBt_Click(object sender, EventArgs e)
{
  FormMain.uc3.ShowDialog();
}

...at the end... in uc3 there is a button to close the form:

private void AbortBt_Click(object sender, EventArgs e)
{
  Close();
}

I can show/close uc3 (FormDateTime) many times without problems but sometimes it happens that I get an ObjectDisposedException when I push the button to show uc3.

I thought that uc3 should not be disposed but it seems that sometimes it happens.

Have I made any mistakes that I don't see?

There is a way to make uc3 UNdisposable until the application is closed?
...or any other way to avoid this problem...

Thanks in advance.

#realJSOP26-Sep-19 5:46

Re: [VS2008 - Compact Framework] How to prevent a closed form from been disposed

26-Sep-19 5:46

Make it modeless. Instead of using form.ShowDialog(), use form.Show(). Whatever button you use to close the ford should hide it instead, using form.Hide().

".45 ACP - because shooting twice is just silly" - JSOP, 2010
-----
You can never have too much ammo - unless you're swimming, or on fire. - JSOP, 2010
-----
When you pry the gun from my cold dead hands, be careful - the barrel will be very hot. - JSOP, 2013

steve_949661326-Sep-19 20:47

Re: [VS2008 - Compact Framework] How to prevent a closed form from been disposed

26-Sep-19 20:47

Thank you #realJSOP for your answer.

I can't apply your solution because the form I show must stay over the others and must be closed to let user access to the window below, so I need a ShowModal().

#realJSOP26-Sep-19 22:53

Re: [VS2008 - Compact Framework] How to prevent a closed form from been disposed

26-Sep-19 22:53

ShowModal will ALWAYS dispose your form when you close it. If you need data shown in the window to be retained, you're going to have to store it in a static class so you can recall it whenever you need it.

dan!sh 27-Sep-19 1:09

Re: [VS2008 - Compact Framework] How to prevent a closed form from been disposed

27-Sep-19 1:09

MSDN states the opposite.

When a form is displayed as a modal dialog box, clicking the Close button (the button with an X at the upper-right corner of the form) causes the form to be hidden and the DialogResult property to be set to DialogResult.Cancel. Unlike non-modal forms, the Close method is not called by the .NET Framework when the user clicks the close form button of a dialog box or sets the value of the DialogResult property. Instead the form is hidden and can be shown again without creating a new instance of the dialog box. Because a form displayed as a dialog box is hidden instead of closed, you must call the Dispose method of the form when the form is no longer needed by your application.

Moreover, if the object is marked as static, I would expect them to be alive and healthy throughout the parent form's life.

"It is easy to decipher extraterrestrial signals after deciphering Javascript and VB6 themselves.", ISanti[^]

#realJSOP27-Sep-19 5:45

Re: [VS2008 - Compact Framework] How to prevent a closed form from been disposed

27-Sep-19 5:45

No, an EXTERNAL static class. I have such a class called Globals that I use for things that have to stick around for the life of the app.

steve_949661329-Sep-19 20:48

Re: [VS2008 - Compact Framework] How to prevent a closed form from been disposed

29-Sep-19 20:48

Hi #realJSOP,
I have declared that object STATIC inside a form that is alive untill the app is closed, why it is not enough?
Thanks

dan!sh 29-Sep-19 23:04

Re: [VS2008 - Compact Framework] How to prevent a closed form from been disposed

29-Sep-19 23:04

I am not sure if I understand this. What I meant was that if I create a static object on the form, it has to be alive until that form (not application) is.

"It is easy to decipher extraterrestrial signals after deciphering Javascript and VB6 themselves.", ISanti[^]

#realJSOP30-Sep-19 1:11

Re: [VS2008 - Compact Framework] How to prevent a closed form from been disposed

30-Sep-19 1:11

When the modal form goes out of scope (closes), you can't access anything declared inside it because the form is no longer available/in scope.

steve_949661330-Sep-19 1:44

Re: [VS2008 - Compact Framework] How to prevent a closed form from been disposed

30-Sep-19 1:44

Clear.

The form is used only to update date and time, it doesn't store any information.

#realJSOP30-Sep-19 2:00

Re: [VS2008 - Compact Framework] How to prevent a closed form from been disposed

30-Sep-19 2:00

Declare an EXTERNAL static class that the form can access

public static class Globals
{
    public static MyDateTime { get; set; }
}

In your form, when you close it:

Globals.MyDateTime = DateTime.Now;

When your form closes, examine Globals.MyDateTime to ensure it's the expected value.

The next time you open the form, the value will be the same as the last time you opened the form, and when you close it agaim, set Globals.MyDateTime again.

The Globals.DateTime will be available everywhere else in the app as well.

steve_949661330-Sep-19 21:27

Re: [VS2008 - Compact Framework] How to prevent a closed form from been disposed

30-Sep-19 21:27

Thanks for the sample #realJSOP.

Actually I don't need to save the exact moment the form is closed.
This form is used to give the user the possibility to change the time and/or the date of the device (Windows CE based) on which the app is running and it is not used to change a variable used somewere else in the app.

So I declared an external static class and in this class I declared my form instance:

public static class Cl_Forms
{
  public static FormDateTime Suc3 = new FormDateTime();
}

As you suggest, in this way the form shown in a modal way should be static and should not be disposed until the app is running.

Now I'm testing this solution.
Unfortunately the exception occurred rarely and randomly and it was not easy to reproduce it.

dan!sh 30-Sep-19 2:04

Re: [VS2008 - Compact Framework] How to prevent a closed form from been disposed

30-Sep-19 2:04

Yes, that is what I said as well.

"It is easy to decipher extraterrestrial signals after deciphering Javascript and VB6 themselves.", ISanti[^]

steve_949661330-Sep-19 1:39

Re: [VS2008 - Compact Framework] How to prevent a closed form from been disposed

30-Sep-19 1:39

Sorry, I was not clear.

I understood what you said, FormMain, in wich I declared a FormDateTime instance, is always in the background and is never closed.

#realJSOP30-Sep-19 2:02

Re: [VS2008 - Compact Framework] How to prevent a closed form from been disposed

30-Sep-19 2:02

I have no idea what you really want. I told you to make the form modelss so it never disposes, and you said it can't be modelss. Then I suggested that you make abn external statuic class because you wanted the form to be model. WTF do you actually want to do?

steve_949661330-Sep-19 2:30

Re: [VS2008 - Compact Framework] How to prevent a closed form from been disposed

30-Sep-19 2:30

I want to understand.

I have made what you suggested and now my app is running with the form instance declared in a static class, sometime I push buttons to see if I get the exception.

But I wanted to know why this is better considering that I had declared the form static instance inside a form that is never closed until the application is running.

WTF...

dan!sh 27-Sep-19 1:08

Re: [VS2008 - Compact Framework] How to prevent a closed form from been disposed

27-Sep-19 1:08

Can you post the complete error message? You say it works sometimes and sometimes does not, makes it tough to respond to.

"It is easy to decipher extraterrestrial signals after deciphering Javascript and VB6 themselves.", ISanti[^]

steve_949661327-Sep-19 1:52