Open new forms in C++ Windows Forms Application

I’m using visual studio 2012 to work with windows form in C++. I’ve gotten help from this link Can’t find Windows Forms Application for C++

I want to have multiple forms. I’ve designed Form2 and included Form2.h into Form1.h . But when I open form2, it appears and fades immediately. This is my code:

the two forms will hide, and if I close form1

the form2 will close too.

I want to open and close forms independent. What must I do?

Any help would be appreciated

1 Answer 1

It is rather striking how removing the project template in VS2012 instantly made everybody write the wrong code. You are using «stack semantics», it is an emulation of the RAII pattern in C++. Or in other words, your Form2 instance gets immediately destroyed when your button_Click() returns. Proper code looks like:

The exact same bug is present in the code that creates the Form1 instance, visible from you having to pass %form1 . It is a bit less obvious because your Main() method keeps executing for the lifetime of the app. Nevertheless, the destructor of the Form1 class will be called twice. Tends to cause havoc when you alter the default one. Same recipe, don’t use stack semantics:

Your app terminates instantly when you call this->Close() because you are closing the main window of your app. Which happens because you passed the Form1 instance to Application::Run(). That’s compatible with the way the vast majority of Windows apps behave, closing the «main window» ends the application.

But that’s not what you want so don’t pass the form instance to Run(). You need another exit condition for your app, usually you’ll want a «when there are no more windows left» condition. Alter your Main() method to look like this:

void OnFormClosed(System::Object ^sender, System::Windows::Forms::FormClosedEventArgs ^e) < Form^ form = safe_cast

opening a window form from another form programmatically

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.

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

6 Answers 6

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

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

Also to close the current form, you may use

I would do it like this:

and to close current form I would use

this.Hide(); instead of

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

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

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 OnPageLoad function runs when that form is loaded

In NewForm.cs ,

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.

Open a WPF Window from WinForms & link form app with WPF app

I’m using Visual studio 2012 & I’m using Win Form app called Form1 & add a new item which is wpf Window is called «wpfWin». I want to open the wpfWin through a button in the Form1 once it’s clicked, it opened — separated windows-.

I have tried weblogs.asp but I haven’t found the «WPF Custom Control Library» & once I skip it an error appeared. Is there any other way?!

Also, how can I link Two applications one in WinForm & the other Wpf ?!

3 Answers 3

Open WPF window in WindowsForm APP so you are having issues with the above linked tutorial and question? The «WPF Custom Control Library» is the WPF window that you want to use in your Win-Forms app.

Just a brief explanation as it is explained a few times through the question and tutorial. You will want to open the win-forms project you are currently working on. Then you will want to go to Solution Explorer and right-click the SOLUTION, not the project, go to «Add» and select «New Project».

In the add new Project go to Visual C# and then Windows in the tree on the left hand side. They should be located in the installed sub menu. In the main section you should see «WPF Custom Control Library» click on it and then name it what you would like and click ok.

Add a Window(WPF) control to the project, this window would be the WPF window that you want to open.

Then from the WinForm, open it like so:

However ensure you have the following using statements:

You will need to add some references as well to make this work correctly, here is the list which should be all you need to add to a win-forms:

You should add these to your Win-forms project using the reference picker in VS by right-clicking the reference folder in the solution explorer and adding a new reference. All of the references are located in the Framework tab, sans your WPF control which is in the solution tab.

Open a URL from Windows Forms

I’m trying to provide a link to my company’s website from a Windows Form. I want to be well behaved and launch using the user’s preferred browser.

What is the best way to open a URL in the user’s default browser from a Windows Forms application?

6 Answers 6

This article will walk you through it.

This approach has worked for me, but I could be missing something important.

Here is the best of both worlds:

I found that the answer provided by Blorgbeard will fail when a desktop application is run on a Windows 8 device. To Camillo’s point, you should attempt to open this with the user’s default browser application, but if the browswer application is not assigned, an unhandled exception will be thrown.

I am posting this as the answer since it handles the exception while still attempting to open the link in the default browser.

I like approach described here. It takes into account possible exceptions and delays when launching the browser.

For best practice make sure you don’t just ignore the exception, but catch it and perform an appropriate action (for example notify user that opening the browser to navigate him to the url failed).

For those getting a «Win32Exception: The System cannot find the file specified»

This should do the work:

UseShellExecute is descriped further here

For me the issue was due to the .NET runtime as descriped here

The above approach is perfect, I would like to recommend this approach to where you can pass your parameters.

How to: Open files with the OpenFileDialog

The System.Windows.Forms.OpenFileDialog component opens the Windows dialog box for browsing and selecting files. To open and read the selected files, you can use the OpenFileDialog.OpenFile method, or create an instance of the System.IO.StreamReader class. The following examples show both approaches.

In .NET Framework, to get or set the FileName property requires a privilege level granted by the System.Security.Permissions.FileIOPermission class. The examples run a FileIOPermission permission check, and can throw an exception due to insufficient privileges if run in a partial-trust context. For more information, see Code access security basics.

You can build and run these examples as .NET Framework apps from the C# or Visual Basic command line. For more information, see Command-line building with csc.exe or Build from the command line.

Starting with .NET Core 3.0, you can also build and run the examples as Windows .NET Core apps from a folder that has a .NET Core Windows Forms .csproj project file.

Example: Read a file as a stream with StreamReader

The following example uses the Windows Forms Button control’s Click event handler to open the OpenFileDialog with the ShowDialog method. After the user chooses a file and selects OK, an instance of the StreamReader class reads the file and displays its contents in the form’s text box. For more information about reading from file streams, see FileStream.BeginRead and FileStream.Read.

Example: Open a file from a filtered selection with OpenFile

The following example uses the Button control’s Click event handler to open the OpenFileDialog with a filter that shows only text files. After the user chooses a text file and selects OK, the OpenFile method is used to open the file in Notepad.