Ok I solved it. The issue is when you start your program you have to view each tab. Any tab you have viewed will now populate.
Adding... tabControl1.SelectedIndex = 1; tabControl1.TabPages[1].Parent.Select(); tabControl1.SelectedIndex = 0; tabControl1.TabPages[0].Parent.Select(); ...to the Form Load event solved the issue for me. It happens too fast to see, but gets the job done. Greg -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Greg Hile Sent: Monday, August 30, 2010 12:34 PM To: [email protected] Subject: [DotNetDevelopment] Strange ComboBox issue I am having the strangest issue using C# and VS 2008 Pro I have a Windows Forms application with a tab control with two tabs. List<string> DataA = new List<string> { "", "A", "B", "C", "D" }; List<string> DataB = new List<string> { "", "E", "F", "G", "H" }; private void Form1_Load(object sender, EventArgs e) { comboBox1.DataSource = DataA; comboBox2.DataSource = DataB; } private void button1_Click(object sender, EventArgs e) { comboBox1.Text = "Test1"; comboBox2.Text = "test2"; } Pretty straightforward. Now if I put both comboboxes in the first TabPage when I click button1 it fills in the text even though it is not on the list of it's datasource. That is fine with me, I want it that way. Now, if I move either combobox to the second tabpage then its text will not get populated UNLESS it matches a string from the datasource. So while Combo1 and Combo2 will both end up with "Test1" and "Test2", if I move ComboBox2 to the 2nd tabpage then Combo2.Text will not be populated. If I change the code to say comboBox2.Text = "F"; then it will populate. Anybody have any ideas? Greg
