this.Visible is not working in Windows Forms

c# winforms visible
Barun picture Barun · Sep 18, 2010 · Viewed 38.6k times · Source

I have a problem. I need to hide my window at window load. But

private void Form1_Load(object sender, EventArgs e)
{
    this.Visible = false;
}

is not working. And property Visible remains true. Am I missing something?

Answer

Hans Passant picture Hans Passant · Sep 18, 2010

Yes, the Visible property is a big deal in Windows Forms, that's what actually gets the handle created and causes OnLoad() to run. In other words, the window doesn't exist until it gets visible. And it will ignore attempts to undo this.

It is pretty common to want to still create the handle but not make the window visible if you use a NotifyIcon. You can achieve this by overriding SetVisibleCore:

protected override void SetVisibleCore(bool value) {
    if (!this.IsHandleCreated) {
        value = false;
        CreateHandle();
    }
    base.SetVisibleCore(value);
}

Beware that OnLoad still won't run until the window actually gets visible so move code into the constructor if necessary. Just call Show() in the NotifyIcon's context menu event handler to make the window visible.

Related questions

How do I make a textbox that only accepts numbers?

I have a windows forms app with a textbox control that I want to only accept integer values. In the past I've done this kind of validation by overloading the KeyPress event and just removing characters which didn't fit the …

Read More
ComboBox: Adding Text and Value to an Item (no Binding Source)

In C# WinApp, how can I add both Text and Value to the items of my ComboBox? I did a search and usually the answers are using "Binding to a source".. but in my case I do not have a …

Read More
How do I create a message box with "Yes", "No" choices and a DialogResult?

I want to make simple Yes/No choiced MessageBox, but I think it is nonsense to design a form for that. I thought I could use MessageBox, add buttons, etc. to accomplish this. It is simple, but since there is …

Read More