android fragment解耦,巧用Fragment解耦onActivityResult

最近在研究jsbridge, 一直在想怎么样才能让需要startActivityForResult比如打开相机拍照这样的操作在webView中能更简单一点, 直到我发现了这篇文章

两个类，让你再也不用实现onActivityResult()

看了之后, 马上模仿了文中的代码实现了一下.

Fragment:

public class OnActResultEventDispatcherFragment extends Fragment{

public static final String TAG = "on_act_result_event_dispatcher";

public int mRequestCode = 0x11;

private SparseArray mCallbacks = new SparseArray<>();

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setRetainInstance(true);

}

public void startForResult(Intent intent, ActResultRequest.Callback callback) {

// mRequestCode与callback需要一一对应

mCallbacks.put(mRequestCode, callback);

startActivityForResult(intent, mRequestCode);

mRequestCode++;

}

@Override

public void onActivityResult(int requestCode, int resultCode, Intent data) {

super.onActivityResult(requestCode, resultCode, data);

ActResultRequest.Callback callback = mCallbacks.get(requestCode);

mCallbacks.remove(requestCode);

if (callback != null) {

callback.onActivityResult(resultCode, data);

}

}

}

ActResultRequest:

public class ActResultRequest {

private OnActResultEventDispatcherFragment fragment;

public ActResultRequest(FragmentActivity activity) {

fragment = getEventDispatchFragment(activity);

}

private OnActResultEventDispatcherFragment getEventDispatchFragment(FragmentActivity activity) {

FragmentManager fragmentManager = activity.getSupportFragmentManager();

OnActResultEventDispatcherFragment fragment = findEventDispatchFragment(fragmentManager);

if (fragment == null) {

fragment = new OnActResultEventDispatcherFragment();

fragmentManager

.beginTransaction()

.add(fragment, OnActResultEventDispatcherFragment.TAG)

.commitAllowingStateLoss();

fragmentManager.executePendingTransactions();

}

return fragment;

}

private OnActResultEventDispatcherFragment findEventDispatchFragment(FragmentManager manager) {

return (OnActResultEventDispatcherFragment) manager.findFragmentByTag(OnActResultEventDispatcherFragment.TAG);

}

public void startForResult(Intent intent, Callback callback) {

fragment.startForResult(intent, callback);

}

public interface Callback {

void onActivityResult(int resultCode, Intent data);

}

}

MainActivity:

public class MainActivity extends AppCompatActivity {

private static final String TAG = "MainActivity";

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

}

public void start(View view) {

Intent intent = new Intent(this, SecondActivity.class);

ActResultRequest request = new ActResultRequest(this);

request.startForResult(intent, new ActResultRequest.Callback() {

@Override

public void onActivityResult(int resultCode, Intent data) {

Log.d(TAG, "resultCode = " + resultCode);

String name = data.getStringExtra("name");

Log.d(TAG, "name = " + name);

Toast.makeText(MainActivity.this, "name = " + name + ", resultCode = " + resultCode,

Toast.LENGTH_SHORT).show();

}

});

}

}

SecondActivity

public class SecondActivity extends AppCompatActivity {

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_second);

}

public void returnResult(View view) {

Intent intent = new Intent();

intent.putExtra("name", "mundane");

setResult(RESULT_OK, intent);

finish();

}

}

按照这样的思路, 如果需要简化jsbridge中startActivityForResult的操作, 我们只需要把Fragment和WebView绑定在一起.比如给这个Fragment取名叫WebViewFragment, 它的布局中只有一个我们封装好的WebView, 这个WebView需要监听jsbridge的所有事件我们都在fragment中写好, 包括onActivityResult中的事件, 当然也可以在这个fragment中用一个专门的管理类来管理注册的事件.以后Activity中有用到WebView的地方我们就直接用这个WebViewFragment就好了.也就是说, 把这个WebViewFragment, 当成我们之前的WebView.

github地址: