Android原生嵌入React Native Android原生嵌入React Native详解

package com.reactdemo;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.KeyEvent;

import com.facebook.react.LifecycleState;
import com.facebook.react.ReactInstanceManager;
import com.facebook.react.ReactRootView;
import com.facebook.react.modules.core.DefaultHardwareBackBtnHandler;
import com.facebook.react.shell.MainReactPackage;

public class MainActivity extends AppCompatActivity implements DefaultHardwareBackBtnHandler {

 private ReactInstanceManager mReactInstanceManager;
 private ReactRootView mReactRootView;


 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  mReactRootView = new ReactRootView(this);

  mReactInstanceManager = ReactInstanceManager.builder()
    .setApplication(getApplication())
    .setBundleAssetName("index.android.bundle")
    .setJSMainModuleName("index.android")
    .addPackage(new MainReactPackage())
    .setUseDeveloperSupport(BuildConfig.DEBUG)
    .setInitialLifecycleState(LifecycleState.RESUMED)
    .build();

  mReactRootView.startReactApplication(mReactInstanceManager, "ReactDemo", null);

  setContentView(mReactRootView);
 }

 @Override
 public boolean onKeyUp(int keyCode, KeyEvent event) {
  if (keyCode == KeyEvent.KEYCODE_MENU && mReactInstanceManager != null) {
   mReactInstanceManager.showDevOptionsDialog();
   return true;
  }
  return super.onKeyUp(keyCode, event);
 }

 @Override
 public void onBackPressed() {
  if (mReactInstanceManager != null) {
   mReactInstanceManager.onBackPressed();
  } else {
   super.onBackPressed();
  }
 }

 @Override
 public void invokeDefaultOnBackPressed() {
  super.onBackPressed();
 }

 @Override
 protected void onPause() {
  super.onPause();

  if (mReactInstanceManager != null) {
   mReactInstanceManager.onHostPause();
  }
 }
 @Override
 protected void onResume() {
  super.onResume();

  if (mReactInstanceManager != null) {
   mReactInstanceManager.onHostResume(this, this);
  }
 }
}