opening a window form from another form programmatically

Question

I am making a Windows Forms application. I have a form. I want to open a new form at run time from the original form on a button click. And then close this new form (after 2,3 sec) programatically but from a thread other than gui main thread.

Can anybody guide me how to do it ?
Will the new form affect or hinder the things going on in the original main form ? (if yes than how to stop it ?)

[What have you tried?](http://whathaveyoutried.com) – Kendall Frey Feb 23 '13 at 14:10 — Kendall Frey, Feb 23 '13 at 14:10
Why wait 2,3 seconds? – Ralf de Kleine Feb 23 '13 at 14:11 — Ralf de Kleine, Feb 23 '13 at 14:11
Did you try anything at all? – Mohammad Dehghan Feb 23 '13 at 14:12 — Mohammad Dehghan, Feb 23 '13 at 14:12
It is one of my favorite repeated question.....:) – Sandy Feb 25 '13 at 12:30 — Sandy, Feb 25 '13 at 12:30

score 54 · Answer 1 · edited May 06 '20 at 19:35

54

To open from with button click please add the following code in the button event handler

var m = new Form1();
m.Show();

Here Form1 is the name of the form which you want to open.

Also to close the current form, you may use

this.close();

edited May 06 '20 at 19:35

AustinWBryan

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answered Feb 23 '13 at 14:43

Amrit Sharma

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what is Form1 ? – LongChalk May 02 '19 at 07:30
Form1 is the name of the form to open. If it is named something else, then use something else here. – John Foll Jun 10 '20 at 21:57

score 13 · Answer 2 · edited May 06 '20 at 19:35

13

I would do it like this:

var form2 = new Form2();
form2.Show();

and to close current form I would use

this.Hide(); instead of

this.close();

check out this Youtube channel link for easy start-up tutorials you might find it helpful if u are a beginner

edited May 06 '20 at 19:35

AustinWBryan

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answered Feb 23 '13 at 14:56

Tacit

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score 8 · Answer 3 · edited May 06 '20 at 19:39

This is an old question, but answering for gathering knowledge. We have an original form with a button to show the new form.

The code for the button click is below

private void button1_Click(object sender, EventArgs e)
{
    New_Form new_Form = new New_Form();
    new_Form.Show();
}

Now when click is made, New Form is shown. Since, you want to hide after 2 seconds we are adding a onload event to the new form designer

this.Load += new System.EventHandler(this.OnPageLoad);

This OnPageLoad function runs when that form is loaded

In NewForm.cs ,

public partial class New_Form : Form
{
    private Timer formClosingTimer;

    private void OnPageLoad(object sender, EventArgs e)
    {
        formClosingTimer = new Timer();  // Creating a new timer 
        formClosingTimer.Tick += new EventHandler(CloseForm); // Defining tick event to invoke after a time period
        formClosingTimer.Interval = 2000; // Time Interval in miliseconds
        formClosingTimer.Start(); // Starting a timer
    }
    private void CloseForm(object sender, EventArgs e)
    {
        formClosingTimer.Stop(); // Stoping timer. If we dont stop, function will be triggered in regular intervals
        this.Close(); // Closing the current form
    }
}

In this new form , a timer is used to invoke a method which closes that form.

Here is the new form which automatically closes after 2 seconds, we will be able operate on both the forms where no interference between those two forms.

For your knowledge,

form.close() will free the memory and we can never interact with that form again form.hide() will just hide the form, where the code part can still run

For more details about timer refer this link, https://learn.microsoft.com/en-us/dotnet/api/system.timers.timer?view=netframework-4.7.2

score 1 · Answer 4 · edited May 23 '17 at 12:02

1

You just need to use Dispatcher to perform graphical operation from a thread other then UI thread. I don't think that this will affect behavior of the main form. This may help you : Accessing UI Control from BackgroundWorker Thread

edited May 23 '17 at 12:02

Community

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answered Feb 23 '13 at 14:22

mohamedHabib

196
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score 1 · Answer 5 · answered Jun 17 '19 at 13:56

This might also help:

void ButtQuitClick(object sender, EventArgs e)
{
    QuitWin form = new QuitWin();
    form.Show();
}

Change ButtQuit to your button name and also change QuitWin to the name of the form that you made.

When the button is clicked it will open another window, you will need to make another form and a button on your main form for it to work.

score 0 · Answer 6 · answered Dec 21 '18 at 04:46

private void btnchangerate_Click(object sender, EventArgs e)
    {
        this.Hide();  //current form will hide
        Form1 fm = new Form1(); //another form will open
        fm.Show();


    }

on click btn current form will hide and new form will open

opening a window form from another form programmatically

6 Answers6

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