ListView中的多个秒表计时器

Question

我的Android应用程序中有一个ListView，它应该包含秒表计时器以及每行中的开始和暂停按钮。问题是，当我在一行中启动计时器时，如果我在ListView中启动属于另一行的另一行，则第二行也从第一行所在的同一时间开始。所以基本上他们并不是独立的。如何修改我的代码，以便每一行都有一个独立的计时器，只有当按下它（启动或停止）按钮时，它才会生效。

这是我的自定义适配器类

public class CustomAdapterStopWatch extends BaseAdapter {

private final LayoutInflater layoutInflater;
Context context;
public static List<String> timerList;
private long startTime = 0L;
private Handler customHandler;
long timeInMilliseconds = 0L;
long timeSwapBuff = 0L;
long updatedTime = 0L;

public CustomAdapterStopWatch(Context context, List<String> timerList) {

    this.context = context;
    this.timerList = timerList;
    layoutInflater = LayoutInflater.from(context);
    customHandler = new Handler();
}

@Override
public int getCount() {
    return timerList.size();
}

@Override
public Object getItem(int position) {
    return timerList.get(position);
}


@Override
public long getItemId(int position) {
    return position;
}

@Override
public View getView(final int position, View convertView, ViewGroup parent) {

    final ViewHolder holder;

    if (convertView == null) {
        convertView = layoutInflater.inflate(R.layout.stop_watch_list_view, null);
        holder = new CustomAdapterStopWatch.ViewHolder();
        holder.timerTextView = (TextView) convertView.findViewById(R.id.timerInListView);
        holder.startTimer = (Button) convertView.findViewById(R.id.startTimerInListView);
        holder.pauseTimer = (Button) convertView.findViewById(R.id.stopTimerInListView);
        holder.timerTextView.setTag(position);
        holder.startTimer.setTag(position);
        holder.pauseTimer.setTag(position);
        convertView.setTag(holder);

        // Alarm alarm = (Alarm) getItem(position);
    } else {

        holder = (CustomAdapterStopWatch.ViewHolder) convertView.getTag();
    }
    holder.timerTextView.setText(timerList.get(position));

    holder.startTimer.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

            startTime = SystemClock.uptimeMillis();
            customHandler.postDelayed( new Runnable() {
                public void run() {
                    timeInMilliseconds = SystemClock.uptimeMillis() - startTime;
                    updatedTime = timeSwapBuff + timeInMilliseconds;
                    int secs = (int) (updatedTime / 1000);
                    int mins = secs / 60;
                    secs = secs % 60;
                    int milliseconds = (int) (updatedTime % 1000);
                    holder.timerTextView.setText("" + mins + ":"
                            + String.format("%02d", secs) + ":"
                            + String.format("%03d", milliseconds));
                    customHandler.postDelayed(this, 0);
                }
            }, 0);

        }
    });


    holder.pauseTimer.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

            timeSwapBuff += timeInMilliseconds;
            customHandler.removeCallbacks(new Runnable() {
                public void run() {
                    timeInMilliseconds = SystemClock.uptimeMillis() - startTime;
                    updatedTime = timeSwapBuff + timeInMilliseconds;
                    int secs = (int) (updatedTime / 1000);
                    int mins = secs / 60;
                    secs = secs % 60;
                    int milliseconds = (int) (updatedTime % 1000);
                    holder.timerTextView.setText("" + mins + ":"
                            + String.format("%02d", secs) + ":"
                            + String.format("%03d", milliseconds));
                    customHandler.postDelayed(this, 0);
                }
            });
        }
    });

    return convertView;
}

我使用的布局文件如下：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">


    <TextView
        android:id="@+id/timerInListView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:text="00:00:00"
        android:textSize="25dp"
        android:textColor="@color/colorGray"/>

    <Button
        android:id="@+id/stopTimerInListView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentRight="true"
        android:layout_marginRight="20dp"
        android:text="Pause"
        android:background="@color/colorGreen"/>

  <Button
    android:id="@+id/startTimerInListView"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginRight="22dp"
    android:text="Start"
    android:background="@color/colorGreen"
    android:layout_alignParentTop="true"
    android:layout_toLeftOf="@+id/stopTimerInListView"
    android:layout_toStartOf="@+id/stopTimerInListView"
    android:layout_marginEnd="22dp" />

 </RelativeLayout>

我使用适配器的秒表类如下：

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

    listView = (ListView) findViewById(R.id.listViewInStopWatch);
    timerList = new ArrayList<String>();


    timerList.add("00:00:000");
    timerList.add("00:00:000");
    timerList.add("00:00:000");
    timerList.add("00:00:000");

    customAdapter = new CustomAdapterStopWatch(StopWatch.this, timerList);
    listView.setAdapter(customAdapter);
 }

更新

我将代码更改为：

public class CustomAdapterStopWatch extends BaseAdapter {

private final LayoutInflater layoutInflater;
Context context;
public static List<TimerState> timerList;
private long startTime = 0L;
private Handler customHandler;
long timeInMilliseconds = 0L;
long timeSwapBuff = 0L;
long updatedTime = 0L;
HashMap<ViewHolder,Integer> mHashHolder;
TimerState state;

public CustomAdapterStopWatch(Context context, final List<TimerState> timerList) {

    this.context = context;
    this.timerList = timerList;
    layoutInflater = LayoutInflater.from(context);
    customHandler = new Handler();
    mHashHolder = new HashMap<ViewHolder,Integer>();
    state = new TimerState();

    // assuming you need to update the timer after every second.
    customHandler.postDelayed(new Runnable() {
        @Override
        public void run() {

            for (ViewHolder holder: mHashHolder.keySet()) {
                state = timerList.get(mHashHolder.get(holder));

                // update the state
            }
        }
    }, 1000);
}

 @Override
public View getView(final int position, View convertView, ViewGroup parent) {

    ViewHolder holder = null;

    if (convertView == null) {
        convertView = layoutInflater.inflate(R.layout.stop_watch_list_view, null);
        holder = new CustomAdapterStopWatch.ViewHolder();
        holder.timerTextView = (TextView) convertView.findViewById(R.id.timerInListView);
        holder.startTimer = (Button) convertView.findViewById(R.id.startTimerInListView);
        holder.pauseTimer = (Button) convertView.findViewById(R.id.stopTimerInListView);
        holder.timerTextView.setTag(position);
        holder.startTimer.setTag(position);
        holder.pauseTimer.setTag(position);
        convertView.setTag(holder);
        mHashHolder.put(holder,position);

        // Alarm alarm = (Alarm) getItem(position);
    } else {
        // holder is being used again, so need to update its new position
        // following line should be synchronized if timer is updated
        // in a separate thread
        mHashHolder.put(holder, position);
        holder = (CustomAdapterStopWatch.ViewHolder) convertView.getTag();
    }
    holder.timerTextView.setText(timerList.get(position).currentTime);

    holder.startTimer.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

            startTime = SystemClock.uptimeMillis();
            if (state.isPaused) {
                state.timeSinceStarted = String.valueOf(SystemClock.uptimeMillis());
                state.isPaused = false;
            } else {
                // nothing
            }

        }
    });


    holder.pauseTimer.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

            if (state.isPaused) {
                state.isPaused = true;
            }
        }
    });

    return convertView;
}


public void startTime(final TextView t) {
     Runnable updateTimerThread = new Runnable() {
        public void run() {
            timeInMilliseconds = SystemClock.uptimeMillis() - startTime;
            updatedTime = timeSwapBuff + timeInMilliseconds;
            int secs = (int) (updatedTime / 1000);
            int mins = secs / 60;
            secs = secs % 60;
            int milliseconds = (int) (updatedTime % 1000);
            t.setText("" + mins + ":"
                    + String.format("%02d", secs) + ":"
                    + String.format("%03d", milliseconds));
            customHandler.postDelayed(this, 0);
        }
    };
}

然而，按下按钮后，没有任何反应。我错过了什么吗？

更新2

 public CustomAdapterStopWatch(Context context, final List<TimerState> timerList) {

    this.context = context;
    this.timerList = timerList;
    layoutInflater = LayoutInflater.from(context);
    customHandler = new Handler();
    mHashHolder = new HashMap<ViewHolder,Integer>();
    state = new TimerState();

    // assuming you need to update the timer after every second.
    customHandler.postDelayed(new Runnable() {
        @Override
        public void run() {

            for (ViewHolder holder: mHashHolder.keySet()) {
                state = timerList.get(mHashHolder.get(holder));

                long tmp;
                if (!state.isPaused) {
                    tmp = SystemClock.uptimeMillis();
                    state.currentTime += tmp - state.timeSinceStarted;
                    state.timeSinceStarted = tmp;
                }
                updatedTime = state.currentTime;
                int secs = (int) (updatedTime / 1000);
                int mins = secs / 60;
                secs = secs % 60;
                int milliseconds = (int) (updatedTime % 1000);
                // set the text of the view in holder
                holder.timerTextView.setText("" + mins + ":"
                        + String.format("%02d", secs) + ":"
                        + String.format("%03d", milliseconds));

                // update the state
            }
        }
    }, 1000);
}

更新3

public class CustomAdapterStopWatch extends BaseAdapter {

private final LayoutInflater layoutInflater;
Context context;
public static List<TimerState> timerList;
private long startTime = 0L;
private Handler customHandler;
long timeInMilliseconds = 0L;
long timeSwapBuff = 0L;
long updatedTime = 0L;
HashMap<ViewHolder,Integer> mHashHolder;
TimerState state;

public CustomAdapterStopWatch(final Context context, final List<TimerState> timerList) {

    this.context = context;
    this.timerList = timerList;
    layoutInflater = LayoutInflater.from(context);
    customHandler = new Handler();
    mHashHolder = new HashMap<ViewHolder,Integer>();
    state = new TimerState();

    // assuming you need to update the timer after every second.

    customHandler.postDelayed(new Runnable() {
        @Override
        public void run() {
            for (ViewHolder holder: mHashHolder.keySet()) {
                state = timerList.get(mHashHolder.get(holder));

                long tmp = 0;
                if (!state.isPaused) {
                    tmp = SystemClock.uptimeMillis();
                    state.currentTime += tmp - state.timeSinceStarted;
                    state.timeSinceStarted = tmp;
                }
                updatedTime = state.currentTime;
                int secs = (int) (updatedTime / 1000);
                int mins = secs / 60;
                secs = secs % 60;
                int milliseconds = (int) (updatedTime % 1000);
                // set the text of the view in holder
                holder.timerTextView.setText("" + mins + ":"
                        + String.format("%02d", secs) + ":"
                        + String.format("%03d", milliseconds));
              //  notifyDataSetChanged();
                Toast.makeText(context,"I got here", Toast.LENGTH_SHORT).show();
                // update the state
            }
            customHandler.postDelayed(this, 1000);
        }
    }, 1000);
}

@Override
public int getCount() {
    return timerList.size();
}

@Override
public Object getItem(int position) {
    return timerList.get(position);
}


@Override
public long getItemId(int position) {
    return position;
}

@Override
public View getView(final int position, View convertView, ViewGroup parent) {

    ViewHolder holder = null;

    if (convertView == null) {
        convertView = layoutInflater.inflate(R.layout.stop_watch_list_view, null);
        holder = new CustomAdapterStopWatch.ViewHolder();
        holder.timerTextView = (TextView) convertView.findViewById(R.id.timerInListView);
        holder.startTimer = (Button) convertView.findViewById(R.id.startTimerInListView);
        holder.pauseTimer = (Button) convertView.findViewById(R.id.stopTimerInListView);
        holder.timerTextView.setTag(position);
        holder.startTimer.setTag(position);
        holder.pauseTimer.setTag(position);
        convertView.setTag(holder);
        mHashHolder.put(holder,position);

        // Alarm alarm = (Alarm) getItem(position);
    } else {
        // holder is being used again, so need to update its new position
        // following line should be synchronized if timer is updated
        // in a separate thread
        mHashHolder.put(holder, position);
        holder = (CustomAdapterStopWatch.ViewHolder) convertView.getTag();
    }
    holder.timerTextView.setText(String.valueOf(timerList.get(position)));

    holder.startTimer.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

            startTime = SystemClock.uptimeMillis();
            if (state.isPaused) {
                state.timeSinceStarted = SystemClock.uptimeMillis();
                state.isPaused = false;



            } else {
                // nothing
            }

        }
    });

    holder.pauseTimer.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

            if (!state.isPaused) {
                state.isPaused = true;
            }
        }
    });

    return convertView;
}


public void startTime(final TextView t) {
     Runnable updateTimerThread = new Runnable() {
        public void run() {
            timeInMilliseconds = SystemClock.uptimeMillis() - startTime;
            updatedTime = timeSwapBuff + timeInMilliseconds;
            int secs = (int) (updatedTime / 1000);
            int mins = secs / 60;
            secs = secs % 60;
            int milliseconds = (int) (updatedTime % 1000);
            t.setText("" + mins + ":"
                    + String.format("%02d", secs) + ":"
                    + String.format("%03d", milliseconds));
            customHandler.postDelayed(this, 0);
        }
    };
}
private class ViewHolder {

    TextView timerTextView;
    Button startTimer;
    Button pauseTimer;
 }
}

Answer 1

实际上有两件事你做错了。

1. 您正在为每个计时器使用相同的变量updateTime。相反，你应该为每个计时器保持一个状态。所以最好有一个单独的类。例如，

   
   class TimerState {
        boolean isPaused = true;
        long currentTime = 0;
        String timeSinceStarted;    // matters only when the timer is started
     }
   
   

所以将上面类的数组列表传递给你的适配器。所以timerList将是TimerState的arrayList。

$str1

1. 这个有点棘手。适配器的作用是重用视图，并且您正在更新某个视图项的计时器（使用postDelayed），即使它对用户不可见。因此，您应该只更新用户可见的那些视图的计时器。我正在创建一个hashmap，它将保留用户可见的所有视图的持有者，并且我们将拥有一个只更新那些视图的runnable。

您的适配器将

    public class CustomAdapterStopWatch extends BaseAdapter {

    private final LayoutInflater layoutInflater;
    Context context;
    public static List timerList;
    private long startTime = 0L;
    private Handler customHandler;
    long timeInMilliseconds = 0L;
    long timeSwapBuff = 0L;
    long updatedTime = 0L;
    // this will contain the holder of all visible views
    HashMap mHashHolder;

    public CustomAdapterStopWatch(Context context, List timerList) {

        this.context = context;
        this.timerList = timerList;
        layoutInflater = LayoutInflater.from(context);
        customHandler = new Handler();

        // assuming you need to update the timer after every second.
        customHandler.postDelayed(new Runnable() {
                @Override
                public void run() {
                    TimerState state;

                    for (ViewHolderItem holder: mHashHolder.keySet()) {
                        state = timerList.get(mHashHolder.get(holder));
                        long tmp;
                        if (!state.isPaused) {
                           tmp = SystemClock.uptimeMillis();
                           state.currentTime += tmp - state.timeSinceStarted)
                           state.timeSinceStarted = tmp;
                        }
                        updatedTime = state.currentTime

                        int secs = (int) (updatedTime / 1000);
                        int mins = secs / 60;
                        secs = secs % 60;
                        int milliseconds = (int) (updatedTime % 1000);
                        // set the text of the view in holder
                        holder.t.setText("" + mins + ":"
                          + String.format("%02d", secs) + ":"
                          + String.format("%03d", milliseconds));
                    }
                    customHandler.postDelayed(this, 1000);
                }
         }, 1000);
    }

    @Override
    public int getCount() {
        return timerList.size();
    }

    @Override
    public Object getItem(int position) {
        return timerList.get(position);
    }


    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public View getView(final int position, View convertView, ViewGroup parent) {

        final ViewHolder holder;

        if (convertView == null) {
            convertView = layoutInflater.inflate(R.layout.stop_watch_list_view, null);
            holder = new CustomAdapterStopWatch.ViewHolder();
            holder.timerTextView = (TextView) convertView.findViewById(R.id.timerInListView);
            holder.startTimer = (Button) convertView.findViewById(R.id.startTimerInListView);
            holder.pauseTimer = (Button) convertView.findViewById(R.id.stopTimerInListView);
            holder.timerTextView.setTag(position);
            holder.startTimer.setTag(position);
            holder.pauseTimer.setTag(position);
            convertView.setTag(holder);

            mHashHolder.put(position, holder);

            // Alarm alarm = (Alarm) getItem(position);
        } else {

            // holder is being used again, so need to update its new position
            // following line should be synchronized if timer is updated
            // in a separate thread
            holder = (CustomAdapterStopWatch.ViewHolder) convertView.getTag();
            mHashHolder.put(holder, position)
        }
        holder.timerTextView.setText(timerList.get(position));

        holder.startTimer.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                startTime = SystemClock.uptimeMillis();
                if (state.isPaused) {
                    state.timeSinceStarted = SystemClock.uptimeMillis();
                    state.isPaused = false;
                } else {
                   // nothing
                }

                // logic for showing the timer will be in onScroll method
            }
        });


        holder.pauseTimer.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                if (!state.isPaused) {
                    state.isPaused = True

                }
            }
        });

        return convertView;
    }

Answer 2

holder.startTimer.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

            startTime = SystemClock.uptimeMillis();
            customHandler.postDelayed( new Runnable() {
                public void run() {
                    timeInMilliseconds = SystemClock.uptimeMillis() - startTime;
                    updatedTime = timeSwapBuff + timeInMilliseconds;
                    int secs = (int) (updatedTime / 1000);
                    int mins = secs / 60;
                    secs = secs % 60;
                    int milliseconds = (int) (updatedTime % 1000);
                    holder.timerTextView.setText("" + mins + ":"
                            + String.format("%02d", secs) + ":"
                            + String.format("%03d", milliseconds));
                    customHandler.postDelayed(this, 0);
                }
            }, 0);

        }
    });

是你的问题。因此，您会看到您声明了一个要计数的变量，当您开始第二个变量时，您会计算相同的变量updatedTime。 要使其独立，您需要将函数更改为不依赖于相同的变量。我的第一个想法是在调用计时器的开始和克隆变量时创建一个新的Thread。但是我在很长一段时间没有为android编程。