Android广播的发送与接收

  
    
 package tech.huqi.application12;
    
 import androidx.appcompat.app.AppCompatActivity;
    
 import android.content.Intent;
    
 import android.os.Bundle;
    
 import android.view.View;
    
 import android.widget.Button;
    
 import android.widget.TextView;
    
 import android.widget.Toast;
    
  
    
 public class Main2Activity extends AppCompatActivity implements View.OnClickListener {
    
     Button button21 = null;
    
     TextView  textView21 = null;
    
     Button button23 = null, button22 = null, button24 = null;
    
  
    
     @Override
    
     protected void onCreate(Bundle savedInstanceState) {
    
     super.onCreate(savedInstanceState);
    
     setContentView(R.layout.activity_main2);
    
  
    
     button21 = findViewById(R.id.button21);
    
     button21.setOnClickListener(this);
    
  
    
     }
    
     @Override
    
     public void onClick(View v) {
    
     int id = v.getId();
    
     switch (id){
    
         case R.id.button21:
    
             Intent tt = new Intent();
    
             tt.setAction("aabbcc");
    
             Bundle bb = new Bundle();
    
             bb.putString("hello","aaa00000----");
    
             tt.putExtras(bb);
    
             sendBroadcast(tt);//发送广播，广播发送器
    
             break;
    
     }
    
     }

 package tech.huqi.application12.data;

    
 import android.content.BroadcastReceiver;
    
 import android.content.Context;
    
 import android.content.Intent;
    
 import tech.huqi.application12.Main2Activity;
    
 public class TRV extends BroadcastReceiver {
    
     @Override
    
     public void onReceive(Context context, Intent intent) {
    
     String str = intent.getExtras().getString("hello");
    
     //Main2Activity.textView21.setText(str);
    
     }
    
 }