に私がインターネットに接続されているかいないかどうか、NetworkChangeをチェックBroadcastReceiverを持っています。 私のアプリケーションでは、ネットワークが切断または接続されているときに、どのアクティビティがBroadcastReceiverを呼び出したのかを知りたいので、ネットワークに関するアラートを表示して前のアクティビティに戻ることができます。
良好ゲッターとセッターを使用してインスタンスと兼ね備え活性のアクティビティを取得する
インスタンスなしアクティビティを取得する放送受信装置で
ActivityManager am = (ActivityManager)context.getSystemService(Context.ACTIVITY_SERVICE);
ComponentName cn = am.getRunningTasks(1).get(0).topActivity;
Log.i("ActivityManager ", "ActivityManager" + cn.toString());
をActivityManagerを使用する放送受信機における現在のアクティビティを取得します。
MyApplication.Java：
public class MyApplication extends Application {
private Activity mCurrentActivity = null;
// Gloabl declaration of variable to use in whole app
public static boolean activityVisible; // Variable that will check the
// current activity state
public static boolean isActivityVisible() {
return activityVisible; // return true or false
}
public static void activityResumed() {
activityVisible = true;// this will set true when activity resumed
}
public static void activityPaused() {
activityVisible = false;// this will set false when activity paused
}
public Activity getCurrentActivity(){
return mCurrentActivity;
}
public void setCurrentActivity(Activity mCurrentActivity){
this.mCurrentActivity = mCurrentActivity;
}
}
MainActivity.Java：
public class MainActivity extends AppCompatActivity {
private static TextView internetStatus;
protected MyApplication mMyApp;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mMyApp = (MyApplication) this.getApplicationContext();
internetStatus = (TextView) findViewById(R.id.internet_status);
// At activity startup we manually check the internet status and change
// the text status
ConnectivityManager connectivityManager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo networkInfo = connectivityManager.getActiveNetworkInfo();
if (networkInfo != null && networkInfo.isConnected()) {
changeTextStatus(true);
} else {
changeTextStatus(false);
}
}
// Method to change the text status
public void changeTextStatus(boolean isConnected) {
// Change status according to boolean value
if (isConnected) {
internetStatus.setText("Internet Connected.");
internetStatus.setTextColor(Color.parseColor("#00ff00"));
} else {
internetStatus.setText("Internet Disconnected.");
internetStatus.setTextColor(Color.parseColor("#ff0000"));
}
}
@Override
protected void onPause() {
super.onPause();
MyApplication.activityPaused();// On Pause notify the Application
clearReferences();
}
@Override
protected void onResume() {
super.onResume();
MyApplication.activityResumed();// On Resume notify the Application
mMyApp.setCurrentActivity(this);
}
protected void onDestroy() {
clearReferences();
super.onDestroy();
}
private void clearReferences() {
Activity currActivity = mMyApp.getCurrentActivity();
Log.e("Activity", "Activity" + currActivity);
if (this.equals(currActivity))
mMyApp.setCurrentActivity(null);
}
}
InternetConnector_Receiver.Java：
public class InternetConnector_Receiver extends BroadcastReceiver {
public InternetConnector_Receiver() {
}
@Override
public void onReceive(Context context, Intent intent) {
try {
boolean isVisible = MyApplication.isActivityVisible();
Log.i("Activity is Visible ", "Is activity visible : " + isVisible);
ActivityManager am = (ActivityManager)context.getSystemService(Context.ACTIVITY_SERVICE);
ComponentName cn = am.getRunningTasks(1).get(0).topActivity;
Log.i("ActivityManager", "Activity Name:" + cn.toString());
// If it is visible then trigger the task else do nothing
if (isVisible == true) {
ConnectivityManager connectivityManager = (ConnectivityManager) context
.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo networkInfo = connectivityManager
.getActiveNetworkInfo();
// Check internet connection and accrding to state change the
// text of activity by calling method
if (networkInfo != null && networkInfo.isConnected()) {
new MainActivity().changeTextStatus(true);
} else {
new MainActivity().changeTextStatus(false);
}
}
} catch (Exception e) {
e.printStackTrace();
}
}
}
マニフェスト権限：
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<application
android:name="com.internetconnection_demo.MyApplication"
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name=".MainActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<!-- Broadcast receiver declaration in manifest file and make sure to enable it -->
<receiver
android:name="com.internetconnection_demo.InternetConnector_Receiver"
android:enabled="true" >
<intent-filter>
<!-- Intent filters for broadcast receiver -->
<action android:name="android.net.conn.CONNECTIVITY_CHANGE" />
<action android:name="android.net.wifi.WIFI_STATE_CHANGED" />
<action android:name="android.net.wifi.STATE_CHANGE" />
</intent-filter>
</receiver>
</application>
「これを引き起こした」とは、意図を送ったエンティティを意味しますか？私はあなたができるとは思わない。これを行うシステムでなければなりません。 –