1.實現Activity到Fragment之間的跳轉

首先在MainActivity的條件函式中加入如下程式碼

Intent mIntent = new Intent(MainActivity.this,Menu.class);
mIntent.putExtra("id",1);
startActivity(mIntent);

然後在Menu中接收傳遞過來的id值，對值進行判斷，開啟對應Fragment

int id = getIntent().getIntExtra("id", 0);
if (id == 1) {
    getSupportFragmentManager().beginTransaction().add(R.id.main_frame, thirdFragment).show(thirdFragment).commit();
   // fragment = thirdFragment;
}
 

2.實現Fragment到Activity的跳轉

只需要在Fragment中跳轉函式寫入如下程式碼

Intent intent = new Intent(getActivity(),MainActivity.class); 
startActivity(intent);

3.從一個Activity中Fragment跳轉到另一個Activity中的Fragment

在第一個Fragment中加入如下程式碼

Intent mIntent = new Intent(getActivity(),Menu.class);
mIntent.putExtra("id",1);
startActivity(mIntent);
 

然後在Menu中接收傳遞過來的id值，對值進行判斷，開啟對應Fragment 

int id = getIntent().getIntExtra("id", 0);
if (id == 1) {
    getSupportFragmentManager().beginTransaction().add(R.id.main_frame, thirdFragment).show(thirdFragment).commit();
   // fragment = thirdFragment;
}