如何在不丢失数据的情况下返回上一个表格

Question

I have a first form where the user designs a hotel for himself/herself. After clicking on a created room from the created floor, the user introduces information to a second form which opens from the first form in order to reserve that room. When a button is clicked on the second form the form should disappear sending the data to the first form then save it to a file in the first form.

My issue is that when I am trying to hide or to close the second form, it either exits the application or it just hides the tab.

Could anyone tell me how to close the second form an get back to the first form without losing any data, any buttons, any text or any information example in a combo box.

Code wise that is what I have in the Program.cs:

static void Main()
        {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);

            Form1 myStart = new Form1();

            if (myStart.ShowDialog() == DialogResult.OK)
            {
                Application.EnableVisualStyles();
                Application.SetCompatibleTextRenderingDefault(false);
                Application.Run(new Form1());
            }
            else
            {
                Application.Exit();
            }
        }

And that is what I tried to put in the button that closes the second form, but it does not work :

Form2Reservations f2 = new Form2Reservations();
            f2.Close();

and I also tried :

var main = new Form1();
           main.Show();
           main.BringToFront(); , but it gives me a new Form1 and I do not want to lose everything that I already had in Form1.

and I also tried this.Close(); and this.Hide(); , but the first one closes the whole application and the second one just puts both tabs on the toolbar.

Also, I am a beginner in C#, I have not taken any University level courses, I am just self-teaching myself with the help of the internet and tutorials.

Thank you.

SECOND EDIT: When I open up my second form I use this code in form 1:

Form2Reservations f2 = new Form2Reservations();
                f2.receiveDataFromForm1(typeOfRoom, numberOfTheRoom, floor);
                f2.ShowDialog();
                this.Hide();

The edited changeRoom_Click looks like this :

private void changeRoomButton_Click(object sender, EventArgs e)
        {
            this.DialogResult = System.Windows.Forms.DialogResult.OK;
            this.Close();
        }

And the Program.cs code with static void Main() still looks the same.

My idea is the following : Is there any chance that I am not opening the second form correctly, so when I want to close the second form, it closes both of them, because somehow they are closely connected and this.Close() is referring to both forms ? Is that possible ? Would my mistake be in the first form when I call the opening of the second form ?

Answer 1

You are checking if the DialogResult is set on 'OK'. But you aren't setting the DialogResult before Closing the form, which is why it will return False on the If statement and exits the application.

You need to add this.DialogResult = System.Windows.Forms.DialogResult.OK; before closing the Form in changeRoomButton_Click .

--EDIT:

Lets give it another try.

You are calling receiveDataFromForm1 before you actually have showed the form, therefor it probably isn't going to return anything. Also, you don't need the hide the existing form when calling ShowDialog as it will stay on top until you close it.

Your code is a real mess so I'll just throw something together as an example to help you progress;

In Program.cs :

        frmReservations reservations = new frmReservations();
        if (reservations.ShowDialog() == DialogResult.OK)
        {
            string result = reservations.yourDesiredResult;
            Application.Run(new frmMain(result));
        }
        else
        {
            Application.Exit();
        }

Now, inside frmReservations :

public partial class frmReservations : Form
{
    public string yourDesiredResult = string.Empty;
    private void btnClose_Click(object sender, EventArgs e)
    {
        this.DialogResult = System.Windows.Forms.DialogResult.OK;
        this.yourDesiredResult = "I've been set!";
        this.Close();
    }
}

Now inside frmMain you will have to receive that value again we've received from frmReservations and set in Program.cs :

public partial class frmMain : Form
{
      public frmMain(string resultFromReservations)
      {
           InitializeComponent();
           //resultFromReservations holds the string: I've been set
      }
}

This is just an example to show you one of the many ways to do this, you will now have to implement it inside your program.

Answer 2

I found my bug. It was in Program.cs : I had :

static void Main()
        {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);

            Form1 myStart = new Form1();
            Form2Reservations myLogin = new Form2Reservations();

            if (myStart.ShowDialog() == DialogResult.OK)
            {
                Application.EnableVisualStyles();
                Application.SetCompatibleTextRenderingDefault(false);
                Application.Run(myLogin);
            }
            else
            {
                Application.Exit(); // here was the mistake
            }
        }

All I had to do is to change Application.Exit(); to Application.Run(myStart); , but I also needed to include this line in my second form button that closes the second form :

this.DialogResult = System.Windows.Forms.DialogResult.OK;

Thank you guys for help. I could not have fixed it without your help.