Fragment與Activity通信詳解

動態(tài)加載的Fragment

Activity => Fragment

實例化 bundle類 傳遞給 Fragment

//動態(tài)加載?fragment
????????Fragment?fragment?=?new?Fragment();?//這個是我們自己定義的?Fragment
????????FragmentManager?fragmentManager?=?getFragmentManager();
????????FragmentTransaction?fragmentTransaction?=?fragmentManager.beginTransaction();

????????//實例化bundle類
????????Bundle?bundle?=?new?Bundle();
????????bundle.putString("title","學習雷鋒好榜樣");
????????//傳遞數(shù)據(jù)
????????fragment.setArguments(bundle);

????????fragmentTransaction.addToBackStack(null);?//后退按鍵?允許
????????fragmentTransaction.add(R.id.linear,fragment);
????????fragmentTransaction.commit();

Fragment =>Activity

實質就是調用Activity中的方法

Fragment.java

public?interface?MyListener{
????????public?void?sayHello(String?str);
????}

????@Override
????public?void?onAttach(Activity?activity)?{
????????MyListener?listener?=?(MyListener)getActivity();
????????listener.sayHello("Fragment?傳遞給?Activity?的數(shù)據(jù)！");
????????super.onAttach(activity);
????}

MainActivity.java

public?class?MainActivity?extends?ActionBarActivity?implements?Fragment.MyListener
...
...
???@Override
????public?void?sayHello(String?str)?{
????????Toast.makeText(MainActivity.this,str,Toast.LENGTH_LONG).show();
????}

靜態(tài)加載的Fragment

Activity => Fragment

實質就是調用Fragment類中的方法

public?class?Fragment?extends?android.app.Fragment?{

????private?String?str;

????public?void?setStr(String?str)?{
????????this.str?=?str;
????}

????public?String?getStr()?{
????????return?str;
????}

MainActivity.java

FragmentManager?fragmentManager?=?getFragmentManager();
????????android.app.Fragment?fragmentById?=?fragmentManager.findFragmentById(R.id.fragment);
????????Fragment?fragment?=?(Fragment)fragmentById;
????????fragment.setStr("123");

注意：Fragment 的 onCreateView的時候,Activity中的 setStr沒有執(zhí)行
?所以是無法在接收到的

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Fragment =>Activity (和動態(tài)加載一致)