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C# Close MainWindow

Hi,

I have a MainWindow, after processing from this window, I create another Window2.
However I'd like to close the MainWindow bu tkeep Window1 open.
When I close Mainwindow, the Window2 is also closed. Please help.

Thanks,
JT
0
jtran007
Asked:
jtran007
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2 Solutions
 
wdosanjosCommented:
If you close the main window the application closes.  You could create a hidden main window that launches window1 and window2, that way you can close and open windows without exiting the app.

I hope this helps.
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jtran007Author Commented:
Hi,

In WPF, I can do what I told you; but not in winform.Since I have limited memory, I
want to give back resources to window, after I use MainWindow. Your soluition still
keeps three window, eventhough one is hidden, but it still uses memory.

JT
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wdfdo1986Commented:
have an another window in the middle of the main window and window1. give it the main window functionalities and hide the main window.
now u can close the window like main window without closing the app.
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jtran007Author Commented:
HI,
I should increase point value to 500 since it is not easy solution.

JT
0
 
wdfdo1986Commented:
so what do u think about the given solutions.
i suggested one way of doing it.
Or u can implement the on exit event of main window
I can't remember the exact event name.
if u write that event u can stop closing the window
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Mike TomlinsonMiddle School Assistant TeacherCommented:
In program.cs, pass your own implementation of ApplicationContext that only shuts down the app when all forms are closed:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Windows.Forms;
 
namespace WindowsFormsApplication1
{
    static class Program
    {
        /// <summary>
        /// The main entry point for the application.
        /// </summary>
        [STAThread]
        static void Main()
        {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            Application.Run(new MyContext());
        }
    }
 
    public class MyContext : ApplicationContext
    {
        public MyContext()
        {
            Application.Idle += new EventHandler(Application_Idle);
            MainForm mf = new MainForm();
            mf.Show();
        }
 
        void Application_Idle(object sender, EventArgs e)
        {
            if (Application.OpenForms.Count == 0)
                Application.Exit();
        }
 
    }
 
}

Open in new window


Now you can Show() the second form BEFORE you Close() the main form and the app will stay open:
// in MainForm:
Form2 f2 = new Form2();
f2.Show();
this.Close();

Open in new window


The app will close automatically when the LAST open form is closed...
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pchuiCommented:
Use Form.Show() instead of Application.Run() to start your main window. Wait for your program to finish and call Application.DoEvents() to keep the messages pumping.

using System;
using System.Windows.Forms;

namespace TwoWindows
{
    static class Program
    {
        public static Form1 form1;
        public static Form2 form2;

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

            Program.form1 = new Form1();
            Program.form1.Show();

            while (Application.OpenForms.Count > 0)
                Application.DoEvents();
        }
    }
}

Open in new window


Make sure you don't have any lifetime issues with the second window getting destroyed when the first window closes. You can declare the Forms global somewhere as I have done in the main Program class.

You code to create the second window looks like this

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

Open in new window


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Mike TomlinsonMiddle School Assistant TeacherCommented:
@pchui....except that RAMPS CPU usage up because of your TIGHT loop.  The ApplicationContext does the same thing without monopolizing the processor time...
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pchuiCommented:
@Idle_Mind... you are correct. My code needs some to break up the tight loop

while (Application.OpenForms.Count > 0)
{
    System.Threading.Thread.Sleep(100);
    Application.DoEvents();
}

Open in new window


Brings the CPU usage to 0% while idle on my system
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Mike TomlinsonMiddle School Assistant TeacherCommented:
I still wouldn't do it that way but technically it works...
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rajeshjamnadasCommented:
try this logic

i hv created button1 and on click of that following code.
this logic will work for u

      private void button1_Click(object sender, System.EventArgs e)
            {
                  System.Threading.Thread th = new System.Threading.Thread(new System.Threading.ThreadStart(showf));
                  th.Start();
                  this.Close();
                  
            }

            private void showf()
            {
                  Application.Run(new Form1());
            }
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ennixoCommented:
Loops are bad !

I think the best solution is to create your own ApplicationContext, just as Idle_Mind said.
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SAMIR BHOGAYTAFreelancer and IT ConsultantCommented:
Hi, you have to use this code


for(int k = 0;k < Application.OpenFormsk].Count;k++)
{
           Application.OpenForms[k].Close();
}
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SAMIR BHOGAYTAFreelancer and IT ConsultantCommented:
hi, You have to write this code on MainForm_Closing() Event. ok
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jtran007Author Commented:
Hi,

I have a scenario like this: I have 4 windows statically created durin the design time.
And they are dynamically shown as the process is going on.

First: win1 is shown to display instruction, then user click button 1 to go to win2 (win1 is closed now or later: my question )
Second: win2 display progress bar showing the initializastion, when done the program , win2 is closed,
             and program display (show()) win3.
Third: win3 start collecting data, when done, win3 is close, and program display win 4
Fourth: win 4 display completion, and user click close, program exits.

From this scenario, which technique is the best one.

Thanks for your sharing knowlege with me.

JT
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Mike TomlinsonMiddle School Assistant TeacherCommented:
The ApplicationContext approach back here will handle that just fine:
http://www.experts-exchange.com/Programming/Languages/C_Sharp/Q_26813822.html#34867969
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jtran007Author Commented:
Thanks,
JT
0

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