C# Windows Forms Application

Every C# Windows Forms Application should save it's position, size and state for a positive user experience. The following tutorial shows how to save the windows position in the settings when closing the program and how to restore the window when the program is started again.

We need the state, location and size of the form:

• this.WindowState ... maximized, normal, etc.
• this.Location ... window position x/y
• this.Size ... width and height

The settings should be restored when the form loads and saved when the form is closing.

Step 1: Add Variables to  Application Settings

Go to "Properties" > "Settings.settings" and add e.g. the following settings:

• Name: F1State | Type: System.Windows.Forms.FormWindowState | Value: Normal
• Name: F1Location | Type: System.Drawing.Point | Value: 0;0
• Name: F1Size | Type: System.Drawing.Size | Value: 0;0

Step 2: Add the Form Load Function

Open the form, go to "Properties" > "Events" > "Load", in e.g. Form1_Load and press "Enter".

Step 3: Add the Form Closing Function

Go to "Properties" > "Events" > "FormClosing", type in e.g. Form1_Closing and press "Enter".

Step 4: Locate the Load and Closing Functions

Visual Studio has added the load and closing function to your "form1.cs".
e.g.

private void Form1_Load(object sender, EventArgs e)
{

}

private void Form1_Closing(object sender, FormClosingEventArgs e)
{

}

Step 5: Add Code to Form1_Load

Set the state, position and size when the form loads:

private void Form1_Load(object sender, EventArgs e)
{
    this.WindowState = Properties.Settings.Default.F1State;
    this.Location = Properties.Settings.Default.F1Location;
    this.Size = Properties.Settings.Default.F1Size;
}

The values from the application settings are ZERO the first time, so we need to adjust the code. (We don't want a form with height=0 or width=0)

private void Form1_Load(object sender, EventArgs e)
{
    if (Properties.Settings.Default.F1Size.Width==0 || Properties.Settings.Default.F1Size.Height==0)
    {
        // first start
        // optional: add default values
    }
    else
    {
        this.WindowState = Properties.Settings.Default.F1State;
       
        // we don't want a minimized window at startup
        if (this.WindowState == FormWindowState.Minimized) this.WindowState = FormWindowState.Normal;

        this.Location = Properties.Settings.Default.F1Location;
        this.Size = Properties.Settings.Default.F1Size;
    }
}

Step 6: Add Code to Form1_Closing

Save state, position and size when the form is closing.

private void Form1_Closing(object sender, FormClosingEventArgs e)
{
    Properties.Settings.Default.F1State = this.WindowState;
    if (this.WindowState==FormWindowState.Normal)
    {
        // save location and size if the state is normal
        Properties.Settings.Default.F1Location = this.Location;
        Properties.Settings.Default.F1Size = this.Size;
    }
    else
    {
        // save the RestoreBounds if the form is minimized or maximized!
        Properties.Settings.Default.F1Location = this.RestoreBounds.Location;
        Properties.Settings.Default.F1Size = this.RestoreBounds.Size;
    }

    // don't forget to save the settings
    Properties.Settings.Default.Save();
}

Step 7: Define a Minimum Form Size (Optional)

Define a minimum form size in the "Properties" > "Properties" > "Minimum Size".

Step 8: Keep the Settings after Upgrading the Assembly Version (Optional)

User settings are usually lost when upgrading to a new version of a C# desktop application.
The easiest way to fix this is to call: Properties.Settings.Default.Upgrade();

The upgrade function searches for previous versions of your application in the (User) App Data directory and copies the user settings to the new version. Upgrade should only be called the first time after an upgrade of the version number.

We can e.g. use the "F1Size.Width" for this purpose ... if the width is 0 (the default value in the user settings table) then the application was started the first time or the first time after an upgrade of the version number.

It's important to add the code before accessing the user settings, e.g. in the Form1_Load function:

private void Form1_Load(object sender, EventArgs e)
{
    // Upgrade?
    if (Properties.Settings.Default.F1Size.Width==0) Properties.Settings.Default.Upgrade();

    if (Properties.Settings.Default.F1Size.Width==0 || Properties.Settings.Default.F1Size.Height==0)
    {
        // first start
        // optional: add default values
    }
    else
    {
        this.WindowState = Properties.Settings.Default.F1State;
       
        // we don't want a minimized window at startup
        if (this.WindowState == FormWindowState.Minimized) this.WindowState = FormWindowState.Normal;

        this.Location = Properties.Settings.Default.F1Location;
        this.Size = Properties.Settings.Default.F1Size;
    }
}