C# program crashes when using autocomplete in TextBox-CodePudding

My program crashes sometimes when I type something in the textbox, but sometimes it does not crash...

private void textBox4_TextChanged(object sender, EventArgs e)
{
    TextBox t = sender as TextBox;

    if (t != null)
    {
        // say you want to do a search when user types 1 or more chars
        if (t.Text.Length >= 1)
        {
            this.textBox4.AutoCompleteCustomSource.AddRange(Artikel);
        }
    }
}

Artikel is a string array with a bunch of names

string[] Artikel;

The problem is that its a 50/50 thing, sometimes it crashes and sometimes it doesn't, even with the same characters I type inside the textbox.

CodePudding user response：

Adding as answer, to complete the Q&A, and so that others find the solution.

The OP has moved the assignment of the AutoCompleteCustomSource property to the MouseClick event handler instead of setting it inside the TextChanged event handler.