在RecyclerView和方法中使用CountDownTimers

Question

我有一个关于在回收视图中的多个定时器的问题。我现在已经有了功能性的rv，但是我一直在重写onStop，onPause，onResume方法。我希望我的应用程序在关闭时继续倒计时。请帮我找到解决方案，我有点新的android。

我的代码：

Holder类

public class MyViewHolder extends RecyclerView.ViewHolder { 

private long timeCountInMilliSeconds = 1 * 60000; 

public long timeLeft = 0; 

private enum TimerStatus { 
    STARTED, 
    STOPPED 
} 

public TextView title; 
private TimerStatus timerStatus = TimerStatus.STOPPED; 
private ProgressBar progressBarCV; 
public TextView textViewTimeCV; 
private CountDownTimer countDownTimer; 

public MyViewHolder(View view) { 
    super(view); 
    initViews(view); 
} 

private void initViews(View view) { 
    title = (TextView) view.findViewById(R.id.title); 
    progressBarCV = (ProgressBar) view.findViewById(R.id.progressBarCV); 
    textViewTimeCV = (TextView) view.findViewById(R.id.textViewTimeCV); 
} 

public void startStop(String minutes) { 
    if (timerStatus == TimerStatus.STOPPED) { 

     // call to initialize the timer values 
     setTimerValues(minutes); 
     // call to initialize the progress bar values 
     setProgressBarValues(); 
     // changing the timer status to started 
     timerStatus = TimerStatus.STARTED; 
     // call to start the count down timer 
     startCountDownTimer(); 

    } else { 

     // changing the timer status to stopped 
     timerStatus = TimerStatus.STOPPED; 
     stopCountDownTimer(); 
    } 
} 

private void setTimerValues(String minutes) { 
    int time = 0; 
    if (!minutes.isEmpty() || Integer.parseInt(minutes) != 0) { 

     time = Integer.parseInt(minutes); 
    } 

    // assigning values after converting to milliseconds 
    timeCountInMilliSeconds = time * 60 * 1000; 
} 

private void startCountDownTimer() { 
    countDownTimer = new CountDownTimer(timeCountInMilliSeconds, 1000) { 
     @Override 
     public void onTick(long millisUntilFinished) { 

      textViewTimeCV.setText(hmsTimeFormatter(millisUntilFinished)); 

      progressBarCV.setProgress((int) (millisUntilFinished/1000)); 

      timeLeft = millisUntilFinished; 

      Log.d("timeLeft", String.valueOf(timeLeft)); 

     } 

     @Override 
     public void onFinish() { 

      textViewTimeCV.setText(hmsTimeFormatter(timeCountInMilliSeconds)); 
      // call to initialize the progress bar values 
      setProgressBarValues(); 
      // changing the timer status to stopped 
      timerStatus = TimerStatus.STOPPED; 
     } 

    }.start(); 
} 

private void stopCountDownTimer() { 
    countDownTimer.cancel(); 
} 

private void setProgressBarValues() { 

    progressBarCV.setMax((int) timeCountInMilliSeconds/1000); 
    progressBarCV.setProgress((int) timeCountInMilliSeconds/1000); 
} 

private String hmsTimeFormatter(long milliSeconds) { 

    String hms = String.format("%02d:%02d:%02d", 
      TimeUnit.MILLISECONDS.toHours(milliSeconds), 
      TimeUnit.MILLISECONDS.toMinutes(milliSeconds) - TimeUnit.HOURS.toMinutes(TimeUnit.MILLISECONDS.toHours(milliSeconds)), 
      TimeUnit.MILLISECONDS.toSeconds(milliSeconds) - TimeUnit.MINUTES.toSeconds(TimeUnit.MILLISECONDS.toMinutes(milliSeconds))); 

    return hms; 
}} 

Model类

public class Task { 
private String title; 
private String time; 

public Task() { 
} 

public Task(String title, String description, String time) { 
    this.title = title; 
    this.time = time; 
} 

public String getTitle() { 
    return title; 
} 

public void setTitle(String name) { 
    this.title = name; 
} 

public String getTime() { 
    return time; 
} 

public void setTime(String time) { 
    this.time = time; 
}} 

适配器

public class TaskAdapter extends RecyclerView.Adapter<MyViewHolder> { 

private List<Task> taskList; 

public TaskAdapter(List<Task> taskList) { 
    this.taskList = taskList; 
} 

@Override 
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) { 
    View itemView = LayoutInflater.from(parent.getContext()) 
      .inflate(R.layout.cardview_layout, parent, false); 
    MyViewHolder holder = new MyViewHolder(itemView); 
    return holder; 
} 

@Override 
public void onBindViewHolder(MyViewHolder holder, int position) { 
    Task task = taskList.get(position); 
    holder.title.setText(task.getTitle()); 
    holder.textViewTimeCV.setText(task.getTime()); 
    holder.startStop(task.getTime()); 
} 


@Override 
public int getItemCount() { 
    return taskList.size(); 
}} 

主要活动（这里初始化适配器等）

public class MainActivity extends AppCompatActivity { 


public static List<Task> taskList = new ArrayList<>(); 
private RecyclerView recyclerView; 
public static TaskAdapter tAdapter; 


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

    initializeDrawer(); 

    FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab); 
    fab.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View view) { 
      startActivity(new Intent(MainActivity.this, SecondActivity.class)); 
     } 
    }); 

    recyclerView = (RecyclerView) findViewById(R.id.recycler_view); 
    recyclerView.setDrawingCacheEnabled(true); 
    recyclerView.setItemViewCacheSize(50); 

    tAdapter = new TaskAdapter(taskList); 
    RecyclerView.LayoutManager mLayoutManager = new LinearLayoutManager(getApplicationContext()); 
    recyclerView.setLayoutManager(mLayoutManager); 
    recyclerView.addOnItemTouchListener(new RecyclerViewTouchListener()); 
    recyclerView.setAdapter(tAdapter); 


} 

@Override 
public boolean onCreateOptionsMenu(Menu menu) { 
    // Inflate the menu; this adds items to the action bar if it is present. 
    getMenuInflater().inflate(R.menu.menu_main, menu); 
    return true; 
} 

@Override 
public boolean onOptionsItemSelected(MenuItem item) { 
    // Handle action bar item clicks here. The action bar will 
    // automatically handle clicks on the Home/Up button, so long 
    // as you specify a parent activity in AndroidManifest.xml. 
    int id = item.getItemId(); 

    //noinspection SimplifiableIfStatement 
    if (id == R.id.action_settings) { 
     return true; 
    } 

    return super.onOptionsItemSelected(item); 
} 

@Override 
protected void onResume() { 
    super.onResume(); 
    tAdapter.notifyItemChanged(taskList.size()-1); 
} 

private void initializeDrawer() 
{ 

    AccountHeader headerResult = initializeHeader(); 

    PrimaryDrawerItem item1 = new PrimaryDrawerItem().withIdentifier(1).withName(R.string.app_name); 
    SecondaryDrawerItem item2 = new SecondaryDrawerItem().withIdentifier(2).withName(R.string.slogan_main); 
    //create the drawer and remember the `Drawer` result object 
    Drawer result = new DrawerBuilder() 
      .withActivity(this) 
      .withAccountHeader(headerResult) 
      //.withToolbar(toolbar) 
      .addDrawerItems(
        item1, 
        new DividerDrawerItem(), 
        item2, 
        new SecondaryDrawerItem().withName(R.string.material_drawer_close) 
      ) 
      .withOnDrawerItemClickListener(new Drawer.OnDrawerItemClickListener() { 
       @Override 
       public boolean onItemClick(View view, int position, IDrawerItem drawerItem) { 
        // do something with the clicked item :D 





        return true; 
       } 
      }) 
      .build(); 
} 
private AccountHeader initializeHeader() 
{ 

    AccountHeader headerResult = new AccountHeaderBuilder() 
      .withActivity(this) 
      .withHeaderBackground(R.drawable.drawable_circle_dark_blue) 
      .addProfiles(
        new ProfileDrawerItem().withName("Mike Penz").withEmail("mikepenz@gmail.com").withIcon(getResources().getDrawable(R.drawable.drawable_circle_dark_blue)) 
      ) 
      .withOnAccountHeaderListener(new AccountHeader.OnAccountHeaderListener() { 
       @Override 
       public boolean onProfileChanged(View view, IProfile profile, boolean currentProfile) { 
        return false; 
       } 
      }) 
      .build(); 

    return headerResult;} 

次活动（在这里，我设定值进入我的列表，这是连接到我的adadpter）

public class SecondActivity extends AppCompatActivity implements View.OnClickListener { 

Task task; 


private EditText editTextMinute; 
private ImageView imageViewStartStop; 
private EditText editTextTitle; 

private String title; 
private String minutes; 


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

    // method call to initialize the views 
    initViews(); 
    // method call to initialize the listeners 
    initListeners(); 

} 

/** 
* method to initialize the views 
*/ 
private void initViews() { 
    editTextMinute = (EditText) findViewById(R.id.editTextMinute); 
    imageViewStartStop = (ImageView) findViewById(R.id.imageViewStartStop); 
    editTextTitle = (EditText) findViewById(R.id.editTextTitle); 
} 

/** 
* method to initialize the click listeners 
*/ 
private void initListeners() { 
    imageViewStartStop.setOnClickListener(this); 
} 

/** 
* implemented method to listen clicks 
* 
* @param view 
*/ 
@Override 
public void onClick(View view) { 
    switch (view.getId()) { 
     case R.id.imageViewStartStop: 
      prepareTaskData(title, null, minutes); 

      break; 
    } 
} 


private void prepareTaskData(String title, String description, String time) { 

    time = editTextMinute.getText().toString().trim(); 
    // fetching minutes for Task obj 
    minutes = editTextMinute.getText().toString(); 
    // fetching value from edit text and type cast to string 
    title = editTextTitle.getText().toString(); 
    // toast message to fill edit text 
    if(minutes.isEmpty() || minutes == null || minutes == String.valueOf(0) || title.isEmpty()) 
    { 
     Toast.makeText(getApplicationContext(), getString(R.string.message_minutes_or_title), Toast.LENGTH_LONG).show(); 
    } 
    else 
    { 
     task = new Task(title, description, time); 
     taskList.add(task); 
     tAdapter.notifyItemChanged(taskList.size() - 1); 
     finish(); 
    } 
}} 

也许我应该落实在我的项目服务类？任何inofrmation将对我非常有用

Answer 1

您需要在RecyclerView的onCreateViewHolder方法中添加倒计时器，因为onCreateViewHolder只会被调用一次。

onBindViewHolder将被调用，每次用户滚动或向下

参考this