【Android】22.BroadcastReceiver的动态使用

22.BroadcastReceiver的动态使用

1.下载素材。

本节素材源码，请在公众号回复" AS12142 "。

2.删除AndroidManifest的receiver注册信息。

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="jsz.nopi.firstapp">

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">

        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

3.修改MyRecevier。

public class MyReceiver extends BroadcastReceiver {

    public final static String ACTION = "jsz.nopi.firstapp.intent.action.MyReceiver";

    @Override
    public void onReceive(Context context, Intent intent) {
        System.out.println("接收到了信息是："+intent.getStringExtra("msg"));
    }
}

4.修改MainActivity。

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    private EditText editText;
    private Button button;
    private Button btnReg;
    private Button btnUnReg;
    private MyReceiver receiver;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        editText = findViewById(R.id.editText);
        button = findViewById(R.id.button);
        btnReg = findViewById(R.id.btnReg);
        btnUnReg = findViewById(R.id.btnUnReg);

        button.setOnClickListener(this);
        btnUnReg.setOnClickListener(this);
        btnReg.setOnClickListener(this);

    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.button:
                Intent intent = new Intent(MyReceiver.ACTION);
                intent.putExtra("msg", editText.getText().toString());
                sendBroadcast(intent);
                break;
            case R.id.btnReg:
                if (receiver == null) {
                    receiver = new MyReceiver();
                    registerReceiver(receiver,new IntentFilter(MyReceiver.ACTION));
                }
                break;
            case R.id.btnUnReg:
                if (receiver != null) {
                    unregisterReceiver(receiver);
                    receiver = null;
                }
                break;
        }
    }
}

5.效果图。