I can't believe that disabling specific tabpages (visible but greyed out that means not clickable) is not possible in Visual Studio C# Form app. I have found just a workaround that I couldn't bring to work.(See link below) I wanted to ask this question again, because perhaps there is another solution/workaround in the meantime. How to highlight/grey-out Tabcontrol Tabpage
For just making the tab nonclickable (what is also OK for me) I have used this code, but not working
private void tabControl1_Selecting(object sender,TabControlCancelEventArgs e)
{
if (!e.TabPage.Enabled)
{
e.Cancel = true;
}
}
For example if you want to disable tabPage2 use this code in form load event. It will not show in intellisense but you can type.
Then use tab control selecting event like this