四大组建-Broadcast

广播

1.广播的动态注册

public class MainActivity extends AppCompatActivity {

    private NetworkChangeReceive mNetworkChangeReceive;

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

        IntentFilter intentFilter = new IntentFilter();
        intentFilter.addAction("android.net.conn.CONNECTIVITY_CHANGE");
        mNetworkChangeReceive = new NetworkChangeReceive();
        registerReceiver(mNetworkChangeReceive, intentFilter);
    }

    class NetworkChangeReceive extends BroadcastReceiver {
        @Override
        public void onReceive(Context context, Intent intent) {

            ConnectivityManager connectivityManager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
            NetworkInfo networkInfo = connectivityManager.getActiveNetworkInfo();
            if (networkInfo != null && networkInfo.isAvailable()) {
                Toast.makeText(MainActivity.this, "network 可用", Toast.LENGTH_SHORT).show();
            } else {
                Toast.makeText(MainActivity.this,"network 不可用",Toast.LENGTH_SHORT).show();
            }
        }
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        unregisterReceiver(mNetworkChangeReceive);
    }
}

清单文件权限申请

2.发送标准广播

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        findViewById(R.id.bt).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Intent intent = new Intent();
                intent.setAction("com.zyp.broadcastdemo.MyReceiver");
                sendBroadcast(intent);
            }
        });
    }
}

public class MyReceiver extends BroadcastReceiver {
    public MyReceiver() {
    }

    @Override
    public void onReceive(Context context, Intent intent) {
        // TODO: This method is called when the BroadcastReceiver is receiving
        // an Intent broadcast.
//        throw new UnsupportedOperationException("Not yet implemented");
        Toast.makeText(context, "广播来了", Toast.LENGTH_SHORT).show();
    }
}

3.接收本地广播

public class MainActivity extends AppCompatActivity {

    private LocalBroadcastManager mLocalBroadcastManager;
    private LocalReceive mLocalReceive;

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

        mLocalBroadcastManager = LocalBroadcastManager.getInstance(this);
        findViewById(R.id.bt).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Intent intent = new Intent();
                intent.setAction("com.zyp.broadcastdemo.MyReceiver");
                mLocalBroadcastManager.sendBroadcast(intent);
            }
        });

        IntentFilter intentFilter = new IntentFilter();
        intentFilter.addAction("com.zyp.broadcastdemo.MyReceiver");
        mLocalReceive = new LocalReceive();
        mLocalBroadcastManager.registerReceiver(mLocalReceive, intentFilter);
    }

    class LocalReceive extends BroadcastReceiver {
        @Override
        public void onReceive(Context context, Intent intent) {
            Toast.makeText(context,"接收本地广播",Toast.LENGTH_SHORT).show();
        }
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        mLocalBroadcastManager.unregisterReceiver(mLocalReceive);
    }
}

广播实现强制下线

public class BaseActivity extends AppCompatActivity {

    private ForceOfflineReceive mOfflineReceive;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        ActivityCollector.addActivity(this);
    }

    @Override
    protected void onResume() {
        super.onResume();
        IntentFilter intentFilter = new IntentFilter();
        intentFilter.addAction("zyp.test");
        mOfflineReceive = new ForceOfflineReceive();
        registerReceiver(mOfflineReceive, intentFilter);
    }

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

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

    class ForceOfflineReceive extends BroadcastReceiver {
        @Override
        public void onReceive(final Context context, Intent intent) {
            AlertDialog.Builder builder = new AlertDialog.Builder(context);
            builder.setTitle("warning");
            builder.setMessage("强制下线");
            builder.setCancelable(false);
            builder.setPositiveButton("OK", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialogInterface, int i) {
                    ActivityCollector.finishAll();
                    Intent intent = new Intent(context, LoginActivity.class);
                    context.startActivity(intent);
                }
            });
            builder.show();
        }
    }

}

public class ActivityCollector {
    public static List sActivities = new ArrayList<>();

    public static void addActivity(Activity activity) {
        sActivities.add(activity);
    }

    public static void removeActivity(Activity activity) {
        sActivities.remove(activity);
    }

    public static void finishAll() {
        for (Activity activity:sActivities) {
            if (!activity.isFinishing()){
                activity.finish();
            }
        }
        sActivities.clear();
    }
}

public class LoginActivity extends AppCompatActivity {

    private EditText mEt_account;
    private EditText mEt_pwd;

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

        mEt_account = (EditText) findViewById(R.id.et_account);
        mEt_pwd = (EditText) findViewById(R.id.et_pwd);
        Button bt_login = (Button) findViewById(R.id.bt_login);

        bt_login.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String account = mEt_account.getText().toString().trim();
                String pwd = mEt_pwd.getText().toString().trim();

                if (account.equals("admin") && pwd.equals("123456")) {
                    Intent intent = new Intent(LoginActivity.this, MainActivity.class);
                    startActivity(intent);
                } else {
                    Toast.makeText(LoginActivity.this,"密码不正确",Toast.LENGTH_SHORT).show();
                }
            }
        });

    }
}

public class MainActivity extends BaseActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        findViewById(R.id.bt).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Intent intent = new Intent("zyp.test");
                sendBroadcast(intent);
            }
        });
    }
}