c# - Saving the form state then opening it back up in the same state

Question

I have a small program in winforms that holds 3 buttons. Thus far the program lets the user change a the color of another button by clicking the corresponding button While the third button does not do anything yet. What I want to do is to let the user save changes made to the form (save the form state). So when the form is reopened it opens in that same state as saved.

I hope I am being clear about what I am after

Here is a visualization of the form:

The code that i have so far if any help:

public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            btnToColor.Text = "";
        }

        int c = 0;
        private void btnColorSwap_Click(object sender, EventArgs e)
        {
            if (c == 0)
            {
                btnToColor.BackColor = Color.Yellow;
                c++;

            }

            else if (c == 1)
            {
                btnToColor.BackColor = Color.YellowGreen;

                c++;
            }

            else if (c == 2)
            {
                btnToColor.BackColor = Color.LimeGreen;

                c = 0;
            }

        }
    }

Answer 1

This may/may not be easier for you.

Start by creating a class to hold your state:

public class MyFormState {
    public string ButtonBackColor { get; set; }
}

Now, declare a member for your Form with this object:

public partial class Form1 : Form {
    MyFormState state = new MyFormState();

On form load, check if the config exists, then load it:

private void Form1_Load(object sender, EventArgs e) {
    if (File.Exists("config.xml")) {
        loadConfig();
    }

    button1.BackColor = System.Drawing.ColorTranslator.FromHtml(state.ButtonBackColor);
}

private void loadConfig() {
    XmlSerializer ser = new XmlSerializer(typeof(MyFormState));
    using (FileStream fs = File.OpenRead("config.xml")) {
        state = (MyFormState)ser.Deserialize(fs);
    }
}

When your form is closing.. save the config:

private void Form1_FormClosing(object sender, FormClosingEventArgs e) {
    writeConfig();
}

private void writeConfig() {
    using (StreamWriter sw = new StreamWriter("config.xml")) {
        state.ButtonBackColor = System.Drawing.ColorTranslator.ToHtml(button1.BackColor);
        XmlSerializer ser = new XmlSerializer(typeof(MyFormState));
        ser.Serialize(sw, state);
    }
}

Then you can add members to your state class and they will be written into the config.xml file.