如何在 BroadcastReceiver 中添加 Snackbars？

Question

Snackbars 通过在屏幕底部显示一条简短消息来提供有关操作的轻量级反馈。 Snackbars 可以包含一个动作。

Android还提供了一个toast，主要用于系统消息传递。 Toasts 与 snackbars 类似，但不包含动作且不能从屏幕上滑出。

我的问题

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.widget.Toast;
public class TestReceiver extends BroadcastReceiver {
    @Override
    public void onReceive(final Context context, final Intent intent) {
        Toast.makeText(context, "status", Toast.LENGTH_LONG).show();
    }
}

是否可以像 Toast 那样在 BroadcastReceiver 中显示 Snackbar？

Answer 1

is it posible to show snakbars in BroadcastReceiver like Toast?

由 activity 或片段注册的 BroadcastReceiver，通过 registerReceiver()，可以要求 activity 或片段显示小吃店。

清单注册的 BroadcastReceiver 没有 UI，因此它没有地方显示小吃店。它可以做的是 post 进程内事件总线上的事件（例如，LocalBroadcastManager，greenrobot 的 EventBus，Square 的 Otto），让你在前台的任何 UI知道收到广播。如果 UI 层收到消息，则 activity 或片段可以显示一个小吃店。如果事件总线事件未被拾取，如果合适，您也许可以显示 Notification 作为回退。

Answer 2

正如@CommonsWare先生所说，BroadcastReceiver和Activity/Fragment之间必须有一些传递机制，其中UI被附加。

我尝试在这里添加 interface 例如：

public class TestReceiver extends BroadcastReceiver {

    private DoSomethingInterface callback1;

    public TestReceiver() {
    }

    @Override
    public void onReceive(final Context context, final Intent intent) {
        // pass content text to show in SnackBar
        if(callback1 != null) {
            callback1.passText("status");
        } else {
            Log.e("log","callback from UI is not registered yet..");
        }
    }

    public void registerReceiver(DoSomethingInterface receiver) {
         this.callback1 = receiver;
    }

    public interface DoSomethingInterface {
        public void passText(String text);
    }
}

在显示 SnackBar 的 Activity 或 Fragment 中实施 DoSomethingInterface。确保您需要添加 CoordinatorLayout 以显示 SnakeBar :

public class MainActivity extends Activity implements DoSomethingInterface {

public void onCreate() {
    ...
    // pass reference to interface from onCreate()
    BroadcastReceiver mReceiver = new TestReceiver();
    mReceiver.registerReceiver(this);
    ...
}

    @Override
    public void passText(String text) {
        Snackbar.make(<reference to your coordinator layout>, "text", Snackbar.LENGTH_LONG)
                    .setAction("Ok", <listener>)
                    .setActionTextColor(Color.GREEN)
                    .show();

Answer 3

我的工作代码....

public abstract  class TestReceiver  extends BroadcastReceiver {
    @Override   
    public void onReceive(final Context context, final Intent intent) {
        onNetworkChange();
    } 

    protected abstract void onNetworkChange();
}

在主要活动中

public class MainActivity extends Activity  {

    public void onCreate() {
        ...  mReceiver = new TestReceiver () {
            @Override
            protected void onNetworkChange() {
            snackbar = Snackbar.make(Clayout, "Please check your internet connection and try again", Snackbar.LENGTH_SHORT);
            snackbar.setAction("X", snackbarClickListener);snackbar.setActionTextColor(Color.GREEN);
            ColoredSnackbar coloredsnakbar=new ColoredSnackbar();
            coloredsnakbar.confirm(snackbar).show();
            }
        };      
    }
}

Answer 4

我有一个解决方法，无需在所有活动 onCreate() 方法中对小吃店进行编码。

我们可以使用应用程序class来调用BroadcastReciever。如下代码。

public class MyApplication extends Application implements Application.ActivityLifecycleCallbacks {
    public static Activity appactivity;
@Override
    public void onCreate() {
        super.onCreate();
        registerActivityLifecycleCallbacks(this);
}
@Override
    public void onActivityCreated(Activity activity, Bundle savedInstanceState) {
    }

    @Override
    public void onActivityStarted(Activity activity) {

    }

    @Override
    public void onActivityResumed(Activity activity) {
        appactivity = activity;//here we get the activity
        Intent i = new Intent(this, InternetConnectionInformation.class);
        sendBroadcast(i);//here we are calling the broadcastreceiver to check connection state.
    }
}

现在我们也可以使用 BroadcastReceiver class 来显示 snackbar

public class InternetConnectionInformation extends BroadcastReceiver{
    static Snackbar snackbar; //make it as global
    @Override
    public void onReceive(Context context, Intent intent) {
        ConnectivityManager connectivityManager
                = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo activeNetworkInfo = connectivityManager.getActiveNetworkInfo();

        if (activeNetworkInfo == null || !activeNetworkInfo.isConnected()) {
                InternetConnectionInformation.snack(null, 0, "Network Connection failed.",context.getApplicationContext());
        }else{
            InternetConnectionInformation.hideSnackbar();
        }
    }




    public static void snack (HashMap<String,View.OnClickListener> actions,int priority,String message,Context context) {
     if(MyApplication.appactivity != null){
            snackbar = Snackbar.make(MyApplication.appactivity.findViewById(android.R.id.content), message, Snackbar.LENGTH_INDEFINITE);//MyApplication.appactivity from Application class.
            if (actions != null) {
                Iterator iterator = actions.entrySet().iterator();
                snackbar.setDuration(Snackbar.LENGTH_INDEFINITE);
                while (iterator.hasNext()) {
                    Map.Entry pair = (Map.Entry) iterator.next();
                    snackbar.setAction((String) pair.getKey(), (View.OnClickListener) pair.getValue());
                    iterator.remove(); // avoids a ConcurrentModificationException
                }
            }
            switch (priority) {
                case 0:
                    snackbar.getView().setBackgroundColor(context.getResources().getColor(R.color.accentPink));
                    break;
                case 1:
                    snackbar.getView().setBackgroundColor(Color.parseColor("#66ccff"));
                    break;
                case 2:
                    snackbar.getView().setBackgroundColor(Color.parseColor("#66ff33"));
                    break;
            }
            snackbar.show();
           }
        }
        private static void hideSnackbar(){
            if(snackbar !=null && snackbar.isShown()){
                snackbar.dismiss();
            }
        }
    }

要隐藏快餐栏，我们需要检查连接状态。所以 BroadcastReceiver 注册在 Manifest

<receiver android:name="your.package.name.InternetConnectionInformation">
            <intent-filter>
                <action android:name="android.net.conn.CONNECTIVITY_CHANGE" />
            </intent-filter>
        </receiver>

这很好用并且已经过测试。希望对大家有所帮助。

如何在 BroadcastReceiver 中添加 Snackbars？

How to add Snackbars in a BroadcastReceiver?

android

broadcastreceiver

android-support-library

snackbar

android-support-design