How do I show a “Loading . . . please wait” message in Winforms for a long loading form?

Question

I have a form that is very slow because there are many controls placed on the form.

As a result the form takes a long time to loaded.

How do I load the fo

Answer 1

The best approach when you also have an animated image is this one:

1- You have to create a "WaitForm" that receives the method that it will executed in background. Like this one

public partial class WaitForm : Form
{
    private readonly MethodInvoker method;

    public WaitForm(MethodInvoker action)
    {
        InitializeComponent();
        method = action;
    }

    private void WaitForm_Load(object sender, EventArgs e)
    {
        new Thread(() =>
        {
            method.Invoke();
            InvokeAction(this, Dispose);
        }).Start();
    }

    public static void InvokeAction(Control control, MethodInvoker action)
    {
        if (control.InvokeRequired)
        {
            control.BeginInvoke(action);
        }
        else
        {
            action();
        }
    }
}

2 - You can use the Waitform like this

private void btnShowWait_Click(object sender, EventArgs e)
{
    new WaitForm(() => /*Simulate long task*/ Thread.Sleep(2000)).ShowDialog();
}