[英]Periodic update items on a RecyclerView
我有一個帶有Recycler視圖處理卡的活動。 我有一個SwipeRefreshLayout,所以當我滑動它時,會使用新內容更新RecyclerView。 到現在為止還挺好。
但是,我想每隔X秒更新RecyclerView,因此,例如,如果我在打開活動recylcerview的情況下忘了滑動它,那么它也會自行更新。 為此,我想這樣的事情:(我省略了必要的代碼)。
我的主要活動(包含recyclerview)安排了一個作業,如下所示:
private void scheduleJob() {
ComponentName serviceName = new ComponentName(this, MyJobService.class);
JobInfo jobInfo = new JobInfo.Builder(JOB_ID, serviceName)
.setRequiredNetworkType(JobInfo.NETWORK_TYPE_UNMETERED)
.setRequiresDeviceIdle(false)
.setRequiresCharging(false)
.setPeriodic(3000)
//.setOverrideDeadline(400) // Remove comment for faster testing.
.build();
JobScheduler scheduler = (JobScheduler) getSystemService(Context.JOB_SCHEDULER_SERVICE);
int result = scheduler.schedule(jobInfo);
if (result == JobScheduler.RESULT_SUCCESS) {
Toast.makeText(this,"Start", Toast.LENGTH_LONG).show();
} } }
在MyJobService內部,我通過廣播到我的Activity,以使其必須更新RecylcerView的內容。 負責接收廣播的是一個內部類,如下所示:
public static class MyReceiver extends BroadcastReceiver{
@Override
public void onReceive(Context context, Intent intent) {
DataSource dataSource = new DataSource(context);
items = dataSource.getItems(); // can't do this due to outter class variable
adapter.refresh(ítems); // can't do this due to outter class variable
Toast.makeText(context,"event",Toast.LENGTH_SHORT).show();
}
}
問題出在我的主Activity上,我擁有兩個私有變量,分別稱為items(即ArrayList)和adapter(即recylcerview的適配器),我將項目傳遞給適配器以更新recyclerView內容。內部類我無法訪問外部類變量。 做這樣的事情的正確方法是什么? 我想我太混亂了,我想必須有一種最簡單,更直接的方法來完成我想要的事情。
非常感謝你
好吧,原來我把事情弄得太復雜了。 可以使用像這樣的簡單Handler來完成:
// Create the Handler object (on the main thread by default)
Handler handler = new Handler();
// Define the code block to be executed
private Runnable runnableCode = new Runnable() {
@Override
public void run() {
// Do something here on the main thread
Toast.makeText(getApplicationContext(),"Update",Toast.LENGTH_SHORT).show();
ItemsDS itemsDS = new ItempsDS(getApplicationContext());
items = itemsDS.getItems();
adapter.clear();
adapter.addAll(items);
handler.postDelayed(runnableCode, 1000);
}
};
有兩種方法可以執行此操作:
首先是@akshayBhat提到的,您可以通過從BroadcastReceiver類中刪除static關鍵字來實現:
ArrayList<String> items;
Adapter adapter;
public class MyReceiver extends BroadcastReceiver {
@Override
public void onReceive(Context context, Intent intent) {
DataSource dataSource = new DataSource(context);
items = dataSource.getItems(); // can't do this due to outter class variable
adapter.refresh(ítems); // can't do this due to outter class variable
Toast.makeText(context, "event", Toast.LENGTH_SHORT).show();
}
}
其次是將當前活動狀態的引用傳遞給BroadCast接收器,並使用該引用訪問那里的ClassVariables。
ArrayList<String> items;
Adapter adapter;
public static class MyReceiver extends BroadcastReceiver {
AboutUs mContext;
@Override
public void onReceive(Context context, Intent intent) {
mContext = (AboutUs)context;
DataSource dataSource = new DataSource(context);
mContext.items = dataSource.getItems(); // can't do this due to outter class variable
mContext.adapter.refresh(ítems); // can't do this due to outter class variable
Toast.makeText(context, "event", Toast.LENGTH_SHORT).show();
}
}
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