c# - How to record window position in Windows Forms application settings

Question

It seems like a standard requirement: next time the user launches the application, open the window in the same position and state as it was before. Here's my wish list:

• Window position same as it was
  • Unless the screen has resized and the old position is now off screen.
• Splitters should retain their position
• Tab containers should retain their selection
• Some dropdowns should retain their selection
• Window state (maximize, minimize, normal) is the same as it was.
  • Maybe you should never start minimized, I haven't decided.

I'll add my current solutions as an answer along with the limitations.

Answer 1

My other option is to write more custom code around the application settings and execute it on formLoad and formClosed. This doesn't use data binding.

Drawbacks:

• More code to write.
• Very fiddly. The order you set the properties on formLoad is confusing. For example, you have to make sure you've set the window size before you set the splitter distance.

Right now, this is my preferred solution, but it seems like too much work. To reduce the work, I created a WindowSettings class that serializes the window location, size, state, and any splitter positions to a single application setting. Then I can just create a setting of that type for each form in my application, save on close, and restore on load.

I posted the source code, including the WindowSettings class and some forms that use it. Instructions on adding it to a project are included in the WindowSettings.cs file. The trickiest part was figuring out how to add an application setting with a custom type. You choose Browse... from the type dropdown, and then manually enter the namespace and class name. Types from your project don't show up in the list.

Update: I added some static methods to simplify the boilerplate code that you add to each form. Once you've followed the instructions for adding the WindowSettings class to your project and creating an application setting, here's an example of the code that has to be added to each form whose position you want to record and restore.

    private void MyForm_FormClosing(object sender, FormClosingEventArgs e)
    {
        Settings.Default.CustomWindowSettings = WindowSettings.Record(
            Settings.Default.CustomWindowSettings,
            this, 
            splitContainer1);
    }

    private void MyForm_Load(object sender, EventArgs e)
    {
        WindowSettings.Restore(
            Settings.Default.CustomWindowSettings, 
            this, 
            splitContainer1);
    }