Rendering text is expensive and can reduce the overall performance of your app. This is particularly noticeable on older devices such as the first and second-generation iPhone and iPod touch where every CPU cycle counts. Minimize the amount of text you update and the frequency with which these updates take place.
Let us look at ways to do this.
An FLA has been provided at chapter7\recipe6\recipe.fla within the book's accompanying code bundle.
You will find two text fields sitting on the stage. The first is static and contains the text Elapsed Time:. The second is dynamic, contains a zero and has an instance name of timerField.
We will write some ActionScript to continuously update the timerField with the number of seconds that have elapsed since the app was launched.