广播初体验

今天学下广播的使用

写一个登陆界面

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context="com.example.zvt_110.broadcastbestpractice.LoginActivity">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="60dp"
        android:orientation="horizontal"
        android:padding="20dp">

        <TextView
            android:layout_width="90dp"
            android:layout_height="wrap_content"
            android:layout_gravity="center_vertical"
            android:text="Account:"
            android:textSize="18sp" />

        <EditText
            android:id="@+id/account"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_gravity="center_vertical"
            android:layout_weight="1" />
    </LinearLayout>

    <LinearLayout

        android:layout_width="match_parent"
        android:layout_height="60dp"
        android:orientation="horizontal"
        android:padding="20dp">

        <TextView
            android:layout_width="90dp"
            android:layout_height="wrap_content"
            android:layout_gravity="center_vertical"
            android:text="Password:"
            android:textSize="18sp" />

        <EditText
            android:id="@+id/password"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_gravity="center_vertical"
            android:layout_weight="1"
            android:inputType="textPassword" />
    </LinearLayout>

    <Button
        android:id="@+id/login"
        android:layout_width="match_parent"
        android:layout_height="60dp"
        android:paddingLeft="30dp"
        android:paddingRight="30dp"
        android:text="Login" />

</LinearLayout>

当登陆界面跳转到主界面时，写一个intent触发broadcast

btn_force_offline = findViewById(R.id.force_offline);
btn_force_offline.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View view) {
        Intent intent = new Intent("mybroadcast");
        sendBroadcast(intent);

    }
});

注意那个intent写的，我把他当作一个标识符

然后写一个baseactivity 让所有类都继承自这个类

public class BaseActivity extends AppCompatActivity {

    private ForceOffLineReceiver receiver;

    @Override
    public void onCreate(@Nullable Bundle savedInstanceState, @Nullable PersistableBundle persistentState) {
        super.onCreate(savedInstanceState, persistentState);
        ActivityCollector.addActivity(this);
    }


    @Override
    protected void onResume() {
        super.onResume();
        IntentFilter intentFilter=new IntentFilter();
        intentFilter.addAction("mybroadcast");
        receiver=new ForceOffLineReceiver();
        registerReceiver(receiver,intentFilter);
    }

    @Override
    protected void onPause() {
        super.onPause();
        if (receiver!=null){
            unregisterReceiver(receiver);
        }
        receiver=null;
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        ActivityCollector.removeActivity(this);
    }


    class ForceOffLineReceiver extends BroadcastReceiver {

        @Override
        public void onReceive(final Context context, final Intent intent) {
            AlertDialog.Builder builder = new AlertDialog.Builder(context);

            builder.setTitle("warning");
            builder.setMessage("reboot rightnow");
            builder.setCancelable(false);
            builder.setPositiveButton("OK", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialogInterface, int i) {
                    ActivityCollector.finalAll();
                    Intent intent = new Intent(context, LoginActivity.class);
                    startActivity(intent);
                }
            });

            builder.show();
        }
    }
}

原文链接：http://www.apkbus.com/blog-946024-77502.html