Need help with the error system.invalidoperationexception:

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In the following code, I get the following error in the main program when I call a sup form.

System.InvalidOperationException:

this.Hide();
     Application.EnableVisualStyles();
     Application.SetCompatibleTextRenderingDefault(false);
     Application.Run(new FrmFoodPantry());

What I have tried:

this.Hide();
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(new FrmFoodPantry());

Posted 5-Jul-22 4:42am

PaulaJoannAllen

Updated 5-Jul-22 5:21am

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2 solutions

Solution 2

To add to what Richard has said, you already have a running application, so trying to run a second is never going to work - at best you'd end up with two message pumps, at worst, your app would behave very oddly...

Richard is spot on that you need to create and Sow a new form, but you also need to handle when that form closes.
If you call Show, then the new form is created, and the method you are in continues from the next line immediately - so unless you handle the Form.Closed event for the new form your user will have no "normal" way of closing your app at all since the main form is hidden and cannot be accessed by the user.

Either handle the Closed event and close the main form in the handler, or use ShowDialog and execution of the method will not continue until the new form has been closed.

Posted 5-Jul-22 5:21am

OriginalGriff

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Richard MacCutchan 5-Jul-22 11:28am

Thanks for the extra info.

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Richard MacCutchan · Accepted Answer · 2022-07-05T05:01:00

Solution 1

I do not think you should be calling the Application methods inside your main form. You should use something like:

C#

FrmFoodPantry pantryForm = new FrmFoodPantry();
pantryForm.Show();

Posted 5-Jul-22 5:01am

Richard MacCutchan

Comments

PaulaJoannAllen 5-Jul-22 12:06pm

I entered the code

//this.Hide();
FrmNewMonth pantryForm = new FrmNewMonth();
pantryForm.Show();
//Application.EnableVisualStyles();
//Application.SetCompatibleTextRenderingDefault(false);
//Application.Run(new frmFoodPantry());

And I get a build error.
CS0246 Type or Namespace name 'FrmNewmonth' could not be found.
I have added the form and its code to the project, which shows up under references.

Richard MacCutchan 5-Jul-22 12:07pm

FrmNewMonth is not FrmFoodPantry

PaulaJoannAllen 5-Jul-22 12:46pm

That was a coding error, and it should be FrmNewMonth. FrmNewMonth is a .exe project that was added using the 'Project.Add reference'. I know that this changes the original question, should I let this one be closed and ask it again?

Richard MacCutchan 5-Jul-22 14:37pm

You could just update your question with the correct information, especially everything related to the problem.