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c# second form closing after initialisation

I am trying to create a simple c# application (my first attempt at c# so please be kind). I've created a form with a textbox to capture an "auth code", which is then validated and then a webclient fetches an xml file passing this auth code in to the request. The data sent back is parsed e.c.t.
What i want to do is once the xml comes back and ive done my checks to valid it is all fine. I want to close the first form and load up a second form where i will programmatically add the form components needed to display the xml data in a pretty format.
My problem is that im unable to get the second form to stay open (im no doubt invoking the second form in the wrong manner). Here's what i have:
// close current form
this.Close();
//open new form
xmlViewForm xmlView = new xmlViewForm();
xmlView.Show();
I'm sure you've spotted the mistake im making by now. but just to state the obvious for the sake of completeness, it closes the first form, opens the second, and then immediately the program exits (the second form flashes up for a second obviously).
I've tried a few things but none of them work (including using Application.Run(new xmlViewForm()); instead of instantiating the class and using the show() method. Obviously you know that doesn't work, and now i do too, although i dont understand c# even remotely enough to work out why.
Thanks for any help :)

The first thing that came to mind is that you are closing the form that you opened by calling Application.Run(new MyForm()) or something similar. This form has special significance; it is the "main form" of the application, and when closed, it signals to the application that the user wants to close the entire program, no matter how many other windows are open.
There are two possible fixes. First, and easiest, is simply to Hide() the form you don't want visible instead of calling Close() on it. Though invisible, it's still running, so the application doesn't close.
The second solution is to define a custom "application context" that should be run instead of the "default context" that is created by specifying a main form to watch. You do this by deriving a custom class from System.Windows.Forms.ApplicationContext. With this context specified, you can use it to control termination of the application based on something other than closure of the main form. Example code that launches two "main forms" and keeps track of whether both are still active can be found at the MSDN page for the class. You can do something similar by specifying Load and Close handlers for the main form, then passing them to the child form when the main form instantiates it, thus keeping a count of "open" forms, and closing out the full application when that number is zero. Just make sure the child form loads before closing the main form by calling childForm.Show() before this.Close().

You can not open the second form after closing the main form.
Do this:
//open new form
xmlViewForm xmlView = new xmlViewForm();
xmlView.Show();
// hide current form
this.Hide();
Main form can not be closed because it's the parent form. The child form will never show up if you close the main form.
Or change the xmlViewForm to main form by editing Program.cs file
Application.Run(new XmlViewForm());
Then you can easily call the other form first at the time of loading and close it as you please:
private void XmlViewForm_Load(o, s)
{
// hide current form, and this will remain hidden until the other form is done with it's work
this.Hide();
//open the other form
TheOtherForm _theOtherForm = new TheOtherForm();
_theOtherForm.Show();
}
private void TheOtherForm_Closed(o, s)
{
// show current form
this.Show;
}

C# WinForms Wait on form to proceed

I'm tired and hungry, so I might of missed it, but from what I can see no existing post covers this...
I'm writing a plugin for an application. My plugin loads a form to get some data specifically, it uses the webcam to scan for a barcode. Once it's found a barcode, the form hides itself (incase it's needed again later). This is how I currently call the form that does the barcode work:
string readData = null;
if (eye == null)
{
System.Windows.Forms.Application.EnableVisualStyles();
eye = new CamView();
}
eye.Show();
if (eye.found)
{
readData = eye.readData;
}
return readData;
So, my problem is that eye.show() doesn't block. It makes the form appear and carries right on before there's a chance for the barcode to appear. I imagine I need to use some form of threading or locking, but my crude attempts to do so have just frozen the interface completely.
The "eye" form is basically just a viewfinder for the webcam, and relies on the camera_OnImageCapture event to make it do it's image checks for the barcode.
Is there an elegant way to make the application calling the plugin wait for the form to finish? Or do I just need to add an accept button to the "eye form?"
Cheers. And humble apologies if this is in anyway a repost.

.ShowDialog();
http://msdn.microsoft.com/en-us/library/c7ykbedk.aspx
"You can use this method to display a modal dialog box in your application. When this method is called, the code following it is not executed until after the dialog box is closed."

You are on the right track. You change the code to show CamView as a modal dialog but do no add an Accept button. Instead change camera_OnImageCapture to close the dialog.

C# Forms: Lock Main form and process another form

I want to create something like this.
When the button clicks main form will lock/disable/inaccessible. Then the another form load and do some processing.
(actually when the button clicked, it will read some text from a file and write to db. I put progress bar to give a nice look)
As I said I want to lock/disable/inaccessible main form and load the another form.
How can I do this ?
Please Help
Yohan

new Form().ShowDialog() will do just that.

oldForm.Hide() and newForm().ShowDialog()

as J.N. mentioned, ShowDialog will work, but I think you will need to have your processing code in the new form you open up, as the program will only return and 'unlock' your main form after the new form has finished and closed.
Edit I just saw the comments below the original post, I guess this has been sorted, but I'll leave my comments above just in case

Showing Multiple Instances Of Same Form?

I'm having some serious issues with a WinForm application that I'm working on.
Currently, I'm using Form1.ShowDialog(); to display a form. This code is contained in a background worker that looks for changes in a database. Using Form1.ShowDialog(); only allows 1 form to open at a time, even if there are multiple changes to the database. What I want to have happen is for multiple forms to open at once if there is more than one change in my database.
When I use Form1.Show();, the application blows up. For some reason, the Show() method makes the forms not display properly (all the elements in the form are missing).
Is there anything I can do to make my code work the way I want it to?
Edit: here's a code snippet
//result is a linq result
foreach (var row in result)
{
Form1 Form = new Form1();
Form.ShowDialog();
}

After a first look, I can tell you this:
Showdialog can't work the way you intend: this very method makes the owner inactive until the dialog is closed. In your case, the loop will pause at the first showdialog, then resume when you close the form, opening a new one and so on until the loop is finished.
As for the "show" problem, creating empty forms, I need more information. The rest of the code and the exception(s) you're getting.

Two points from the top of my head:
1) To open more then one form , use non modal (modeless) method (i think
the show() method). see for example http://msdn.microsoft.com/en-us/library/39wcs2dh.aspx
2) I am not sure you can call UI related method from a non UI thread. You might want to send an event to your UI thread from the worker thread and the UI thread will call the show method

Load a form without showing it

Short version: I want to trigger the Form_Load() event without making the form visible. This doesn't work because Show() ignores the current value of the Visible property:
tasksForm.Visible = false;
tasksForm.Show();
Long version: I have a WinForms application with two forms: main and tasks. The main form is always displayed. The user can either click a button to open the tasks form, or click some buttons that just run a task directly without opening the tasks form.
When a user asks to run a task directly, I'd like to just call some public methods on the tasks form without showing it. Unfortunately, the task logic depends on stuff that happens in the Form_Load() event. The only way I can find to trigger Form_Load() is to call Show(). The best I've been able to do is to show the form in the minimized state:
tasksForm.WindowState = FormWindowState.Minimized;
tasksForm.Show();
I suppose the cleanest solution would be to pull the tasks logic out of the tasks form and into a controller class. Then I can use that class from the main form and from the tasks form, and only load the tasks form when I need it visible for the user. However, if it's an easy thing to load the form without displaying it, that would be a smaller change.

Perhaps it should be noted here that you can cause the form's window to be created without showing the form. I think there could be legitimate situations for wanting to do this.
Anyway, good design or not, you can do that like this:
MyForm f = new MyForm();
IntPtr dummy = f.Handle; // forces the form Control to be created
I don't think this will cause Form_Load() to be called, but you will be able to call f.Invoke() at this point (which is what I was trying to do when I stumbled upon this SO question).

It sounds to me like you need to sit down and re-think your approach here. I cannot imagine a single reason your public methods need to be in a form if you are not going to show it. Just make a new class.

I totally agree with Rich B, you need to look at where you are placing your application logic rather than trying to cludge the WinForms mechanisms. All of those operations and data that your Tasks form is exposing should really be in a separate class say some kind of Application Controller or something held by your main form and then used by your tasks form to read and display data when needed but doesn't need a form to be instantiated to exist.
It probably seems a pain to rework it, but you'll be improving the structure of the app and making it more maintainable etc.

From MSDN:
Form.Load
Occurs before a form is displayed for the first time.
Meaning the only thing that would cause the form to load, is when it is displayed.
Form.Show(); and Form.Visible = true; are the exact same thing. Basically, behind the scenes, Show checks for various conditions, then sets Visible to true. So obviously, setting visible to false (which it already is) before showing the form is meaningless.
But let's forget the technicalities. I completely agree with Rich B and Shaun Austin - the logic shouldn't be in that form anyway.

Sometimes this would be useful without it being bad design. Sometimes it could be the start of a migration from native to managed.
If you were migrating a c++ app to .NET for example, you may simply make yourwhole app a child window of the .NET form or panel, and gradually migrate over to the .NET by getting rid of your c++ app menu, status bar, toolbar and mapping teh .NEt ones to your app using platform invoke etc...
Your C++ app may take a while to load, but the .NET form doesn't..in which you may like to hide the .NEt form until your c++ app has initialised itself.
I'd set opacity=0 and visible=false to false after calling show, then when your c++ app loads, then reverse.

If you make the method public, then you could access it directly.... however, there could be some unexpected side effects when you call it. But making it public and calling it directly will not draw the screen or open the form.

Move mandatory initialization code for the form class out of the Load event handler into the constructor. For a Form class, instantiation of an instance (via the constructor), form loading and form visibility are three different things, and don't need to happen at the same time (although they do obviously need to happen in that order).

None of the answers solved the original question, so, add the below, call .Show() to load the form without showing it, then call .ShowForm() to allow it to be visible if you want to after:
private volatile bool _formVisible;
protected override void SetVisibleCore(bool value)
{
base.SetVisibleCore(_formVisible);
}
public void ShowForm()
{
_formVisible = true;
if (InvokeRequired)
{
Invoke((Action) Show);
}
else
{
Show();
}
}