IOS Projects Check Control Constraints!

If you want to save yourself a lot of time trying to track down your app just quitting in Xojo 2018. Check your constraints on ALL of your controls. I would recommend editing each constraint entry within Xojo 2018. You don’t have to make any changes, just pull it up to display and then click done.

I recommend this because my main app would just quit upon trying to Dimension my main page. Thanks to Travis we finally determined that there was an illegal constraint on two of my controls. The Top constraint that was attached to Parent.Left instead of Parent.Top.

The issue was fixed by just editing the Top constraint and closing it. I didn’t have to change the value. It changed to Top by just editing it. It will only fix it in a Xojo 2018 version though so make sure that is what you have your application loaded in.

pesky things - I wrote to Paul about this a while ago, but so far it has a low priority. The controls set themselves up to new constraints whenever they are moved, so it is wise to check all constraints as a final step before compiling.
I have found that it is a good idea to start from the top down, using the topmost control as a reference point for the next line down, and having the top of all controls in one line to be referenced to the top of the one to its left. The top of the leftmost control can be referenced to the bottom of the leftmost control of the line above.

I had this happen in the simulator. Scanning the simulator log found the offender, which is a lot faster than checking a bazillion constraints.