返回栈层层退出
if (getSupportFragmentManager().getBackStackEntryCount() > 0) {
//从返回栈中弹出当前的任务
getSupportFragmentManager().popBackStackImmediate();
}
if (getSupportFragmentManager().getBackStackEntryCount() > 0) {
//从返回栈中弹出当前的任务
getSupportFragmentManager().popBackStackImmediate();
}