c# windows form Tab Order

Question

I have a windows form in C# project that keeps Student Info. I caught the image:

I want to add data with sequential order as follows but when I enter data to Surname textbox, TAB button jumps to E-Mail textbox, then Phone Number textbox and lastly to Date of Birth DateTimePicker.

I made all control's TabStop property "False" on the form except these textboxes. And I arranged their TabOrder via Properties Section as follows 0,1,2.. as I intented. But the order followed as I wrote above. Then I opened Tab Order function via "View" on menu strip.. I clicked all controls which I wanted to use in order, but no use. The form and Tab button act as before. I caught Tab Order function image below:

What shall I do now?

Answer 1

TabIndex is important for controls which are siblings of the same parent. However, if your TextBox and ComboBox controls are each inside different parents then their parent controls must have a the proper TabIndex.

In the Windows Forms Designer you can see which controls are children of which panels by bringing up the Document Outline. Go to View -> Other Windows -> Document Outline.

If each TextBox or ComboBox is directly inside a parent then its TabIndex doesn't matter, it can be 0. It's the parent (and possibly the parent's parent's) TabIndex which needs to be in order.