1.Transform settings adapt for iOS8 2.Avoid directly to reading the data from CGRect data structure.

* In iOS8 the UIScreen's bounds now interface-oriented. More info see     https://developer.apple.com/videos/wwdc/2014/#214
* Avoid directly to reading the data stored in the CGRect data structure. More info see    https://developer.apple.com/library/ios/documentation/graphicsimaging/reference/CGGeometry/index.html