Activity切换Fragment的时候使用hide,和show方法（）现在想切换刷新onHiddenChanged()这个方法没有调用咋回事 ？

[梦想的开拓者]

FragmentManager fm=getSupportFragmentManager();
FragmentTransaction transaction=fm.beginTransaction();
hideFrag(transaction);
switch (i) {
case 0:
tab_home_img.setImageResource(R.drawable.home);
home_text.setTextColor(this.getResources().getColor(R.drawable.myblue));
if(homeFrag==null){
homeFrag=new homeFragment();
transaction.add(R.id.contentview, homeFrag);
Log.v("X", "add()");
}else{
transaction.show(homeFrag);
Log.v("X", "show()");
}

break;
case 1:
if(findFrag==null){
findFrag=new findFragment();
transaction.add(R.id.contentview, findFrag);
}else{
transaction.show(findFrag);
}

tab_find_img.setImageResource(R.drawable.find);
find_text.setTextColor(this.getResources().getColor(R.drawable.myblue));
break;
case 2:
if(personalFrag==null){
personalFrag=new personFragment();
transaction.add(R.id.contentview, personalFrag);
}else{
transaction.show(personalFrag);

}

tab_personal_img.setImageResource(R.drawable.personal);
personal_text.setTextColor(this.getResources().getColor(R.drawable.myblue));
break;

default:
break;
}
transaction.commit();//提交事物


zai
子Frameng中添加
public void onHiddenChanged(){
Log.v("X", "home");
}
但是没有调用到咋回事啊？