LocalBroadcastManger

• 主要作用是避免對其他應用程式的sendBroadcast產生反應，因此才需要LocalBroadcastManger
• 跟普通註冊BroadcastReceiver的方式差不多，差別如下:

註冊方式:

LocalBroadcastManager.getInstance(this).registerReceiver(broadcastReceiver,new IntentFilter(broadcast));

註銷方式:

LocalBroadcastManager.getInstance(this).unregisterReceiver(broadcastReceiver);

傳送方式:

LocalBroadcastManager.getInstance(MainActivity.this).sendBroadcast(intent);

完整程式碼: MainActivity.java

package com.example.cheng.broadcastreciver;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.support.v4.content.LocalBroadcastManager;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {
    private static final String broadcast = "broadcast";
    private Button btn;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        btn= (Button) findViewById(R.id.btn);
        btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent();
                intent.setAction(broadcast);
                intent.putExtra("str", "sendBroadcase");
                LocalBroadcastManager.getInstance(MainActivity.this).sendBroadcast(intent);
            }
        });
    }

    @Override
    protected void onResume() {
        super.onResume();
        LocalBroadcastManager.getInstance(this).registerReceiver(broadcastReceiver,new IntentFilter(broadcast));

    }
    private BroadcastReceiver broadcastReceiver=new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            Toast.makeText(context,intent.getStringExtra("str"),Toast.LENGTH_SHORT).show();
        }
    };

    @Override
    protected void onPause() {
        super.onPause();
        LocalBroadcastManager.getInstance(this).unregisterReceiver(broadcastReceiver);
    }
}