This was one a little more difficult, but shows the tip of the iceberg on what can be achieved with Core Animation. The requirement was to have a button on the view, of which the user could choose the icon, and then the colour of the icon. To make it more complicated, the designer decided..
This a bit of a simple one, but one that I end up looking up all the time. Say you have a text field, but it is saved in your model as a NSNumber. Before conversion, you need to ensure the user has entered in a number and not something silly like ‘cow’. What we..