How to open a new form from another form

user_321959 0
Viewed 540671

I have form which is opened using ShowDialog Method. In this form i have a Button called More. If we click on More it should open another form and it should close the current form.

on More Button's Click event Handler i have written the following code

MoreActions objUI = new MoreActions (); 
objUI.ShowDialog();
this.Close();

But what is happening is, it's not closing the first form. So, i modified this code to 

MoreActions objUI = new MoreActions (); 
objUI.Show();
this.Close();

Here, The second form is getting displayed and within seconds both the forms getting closed.

Can anybody please help me to fix issue. What i need to do is, If we click on More Button, it should open another form and close the first form.

Any kind of help will be really helpful to me.

.net-2.0 winforms .net c#
12 Answers
private void Button1_Click(object sender, EventArgs e)
{
    NewForm newForm = new NewForm();    //Create the New Form Object
    this.Hide();    //Hide the Old Form
    newForm.ShowDialog();    //Show the New Form
    this.Close();    //Close the Old Form
}
user_94674500

You could try adding a bool so the algorithm would know when the button was activated. When it's clicked, the bool checks true, the new form shows and the last gets closed.

It's important to know that forms consume some ram (at least a little bit), so it's a good idea to close those you're not gonna use, instead of just hiding it. Makes the difference in big projects.

user_98567740

You need to control the opening of sub forms from a main form.

In my case I'm opening a Login window first before I launch my form1. I control everything from Program.cs. Set up a validation flag in Program.cs. Open Login window from Program.cs. Control then goes to login window. Then if the validation is good, set the validation flag to true from the login window. Now you can safely close the login window. Control returns to Program.cs. If the validation flag is true, open form1. If the validation flag is false, your application will close.

In Program.cs:

   static class Program
    {
        /// <summary>
        /// The main entry point for the application.
        /// </summary>
        /// 

        //Validation flag
        public static bool ValidLogin = false;

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


            Application.Run(new Login());

            if (ValidLogin)
            {
                Application.Run(new Form1());
            }
        }

    }

In Login.cs:

       private void btnOK_Click(object sender, EventArgs e)
        {
            if (txtUsername.Text == "x" && txtPassword.Text == "x")
            {
                Program.ValidLogin = true;
                this.Close();
            }
            else
            {
                MessageBox.Show("Username or Password are incorrect.");
            }
        }

        private void btnExit_Click(object sender, EventArgs e)
        {
            Application.Exit();
        }
user_13759200

Use this.Hide() instead of this.Close()

user_121364240

Do this to Program.cs

using System;

namespace ProjectName 
{
    public class Program
    {
        [STAThread]
        public static void Main(string[] args) 
        {
            Application.EnableVisualStyles();
            Application.SetDefaultCompatibleTextRendering(false);

            new Form1().Show();

            Application.Run();
        }
    }
}
user_176789080
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