第六章 自定义广播的发送和接收(动态) 1.2

1. SendBroadcastActivity:

package com.example.broadcastdemo;

import android.app.Activity;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;

import androidx.annotation.Nullable;

public class SendBroadcastActivity extends Activity{

    private EditText mEditSendInput;
    private MessageReceiver mMessageReceiver;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_send);
        initView();
        registerBroadcastReceiver();
    }

    private void initView() {
        mEditSendInput = (EditText) this.findViewById(R.id.be_send_input_edit);
    }

    /**
     * 点击后发送广播，这个方法就会被调用
     * @param view
     */
    public void sendBroadcastMessage(View view){
        String content = mEditSendInput.getText().toString();
        Intent intent = new Intent();
        // 添加Action(只有一个
        intent.setAction(Constants.ACTION_SEND_MSG);
        // 通过键值对传值
        intent.putExtra(Constants.KEY_CONTENT, content);
        // 给特定的intent发送广播
        sendBroadcast(intent);
    }

    /**
     * 注册动态广播
     */
    public void registerBroadcastReceiver(){
        IntentFilter intentFilter = new IntentFilter();
        intentFilter.addAction(Constants.ACTION_SEND_MSG);
        mMessageReceiver = new MessageReceiver();
        this.registerReceiver(mMessageReceiver, intentFilter);
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        // 动态广播注册时要取消广播注册，否则会导致内存泄露
        if (mMessageReceiver != null) {
            this.unregisterReceiver(mMessageReceiver);
        }
    }
}

 

2. MessageReceiver:

package com.example.broadcastdemo;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.util.Log;

import java.security.acl.LastOwnerException;

public class MessageReceiver extends BroadcastReceiver {
    private static final String TAG = "MessageReceiver";

    @Override
    public void onReceive(Context context, Intent intent) {
        String action = intent.getAction();
        Log.d(TAG, "action is --" + action);
        String content = intent.getStringExtra(Constants.KEY_CONTENT);
        Log.d(TAG, "content is --" + content);
    }
}

 

3. Constants:

package com.example.broadcastdemo;

public class Constants {
    // 定义action的名字
    public static final String ACTION_SEND_MSG = "com.example.broadcastdemo.SEND_MSG";
    public static final String KEY_CONTENT = "content";
}