◎위챗 : speedseoul
http://stackoverflow.com/questions/3093365/how-can-i-check-the-system-version-of-android
if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.GINGERBREAD) {
// only for gingerbread and newer versions
}
if(Build.VERSION.SDK_INT >= 4.0){ //this code will be executed on devices running on DONUT (NOT ICS) or later }