Question

我正在开发我的第一个应用程序，即秒表

所以使用下面的代码，我可以创建一个秒表，它的工作正常。但是在这一点上，当我完全关闭应用程序并再次启动时，它的统计数据从0：0：0我知道我应该使用共享偏好，但我对此没有足够的了解，所以我不是得到我想要的东西。

public class StopwatchFragment extends Fragment implements View.OnClickListener {
public static StopwatchFragment newInstance() {
    StopwatchFragment fragment = new StopwatchFragment();
    return fragment;
}
FloatingActionButton stopwatchButton;
ImageView stopwatchReplayButton, stopwatchShareButton;
TextView timerValue;
private long startTime=0L;
long timeInMilliSec= 0L;
long timeSwapBuff=0L;
long updatedTime=0L;
int secs, mins, millisec;


private Handler customHandler= new Handler();

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {


    View view = inflater.inflate(R.layout.stopwatch, container, false);
    stopwatchButton=(FloatingActionButton) view.findViewById(R.id.stopwatchButton);
    stopwatchButton.setOnClickListener(this);

    timerValue=(TextView) view.findViewById(R.id.timerValue);

    stopwatchReplayButton=(ImageView)view.findViewById(R.id.stopwatchReplayButton);
    stopwatchReplayButton.setOnClickListener(this);

    stopwatchShareButton=(ImageView)view.findViewById(R.id.stopwatchShareButton);
    stopwatchShareButton.setOnClickListener(this);

    return view;
}

@Override
public void onClick(View view) {

    if(view==stopwatchButton)
    {
        if(stopwatchButton.getTag().toString().equals("off"))
        {
            stopwatchButton.setTag("on");
            stopwatchButton.setImageResource(R.drawable.pause);
            startTime= SystemClock.uptimeMillis();
            customHandler.postDelayed(updateTimerThread,0);
            stopwatchReplayButton.setVisibility(View.VISIBLE);
        }
        else
        {
            stopwatchButton.setTag("off");
            stopwatchShareButton.setVisibility(View.VISIBLE);
            stopwatchButton.setImageResource(R.drawable.play);
            timeSwapBuff+=timeInMilliSec;
            customHandler.removeCallbacks(updateTimerThread);
        }
    }

    if(view==stopwatchReplayButton)
    {
        customHandler.removeCallbacks(updateTimerThread);
        timerValue.setText("0 : 00 : 00");
        stopwatchButton.setTag("off");
        stopwatchButton.setImageResource(R.drawable.play);
        timeInMilliSec= 0L;
        timeSwapBuff=0L;
        updatedTime=0L;
    }

    if(view==stopwatchShareButton)
    {
        String text="My Time is "+mins+" : "+secs+" : "+millisec;
        Intent i=new Intent(Intent.ACTION_SEND);
        i.setType("text/plain");
        i.putExtra(Intent.EXTRA_TEXT,text);
        startActivity(Intent.createChooser(i,"Share Using"));
    }

}
private Runnable updateTimerThread=new Runnable() {
    @Override
    public void run() {
        timeInMilliSec = SystemClock.uptimeMillis() - startTime;
        updatedTime = timeSwapBuff + timeInMilliSec;

        secs = (int) (updatedTime / 1000);
        mins = secs / 60;
        secs = secs % 60;
        millisec = (int) (updatedTime % 1000);
        timerValue.setText("" + mins + " : " + String.format("%02d", secs) + " : " + String.format("%03d", millisec));

        customHandler.postDelayed(this, 0);

    }
};

}

我只想实现：如果用户按下停止按钮停止秒表，并假设计时器值为0：3：50，那么即使在完全关闭应用程序后，用户也应该在打开时获取最后一个计时器值该应用程序，

Answer 1

    SharedPreferences settings = getSharedPreferences("YOUR_PREF_NAME", 0);
SharedPreferences.Editor editor = settings.edit();
editor.putInt("SNOW_DENSITY",mSnowDensity);
editor.commit();

//To retrieve
SharedPreferences settings = getSharedPreferences("YOUR_PREF_NAME", 0);
int snowDensity = settings.getInt("SNOW_DENSITY", 0);

试试这个..

Answer 2

     final static int READ=1;
    final static int WRITE=2;
    private List<HashMap<String, String>> ListMaps=
            new ArrayList<HashMap<String, String>>();
    private String FileName="CData";
    private String F_Path="";
}
F_Path=FileName;
        Log.d("F_Path", " File Path :"+F_Path);
        load_data();
public void Add_Data(){
        Log.d("Add", "Add Data Calling");
        HashMap<String, String> map= new HashMap<String, String>();
        map.put("Name",d_name_et.getText().toString() );
        ListMaps.add(map);
        d_name_et.setText("");
        Disp_Data();
    }
    public void Save_Data(){
        Log.d("Save", "Save Data Calling");

        try {
            writeListToFile((ArrayList<HashMap<String, String>>) ListMaps);
        } catch (Exception e) {
            Log.d("Save", "writeListToFile  call error");
        }

    }

    public void Disp_Data(){
        Log.d("Disp_Data()", "Disp_Data() Calling--->");
        String CurData="";
        for (int i=0; i < ListMaps.size();i++){
            HashMap<String, String> map=ListMaps.get(i);
            CurData =CurData+map.get("Name")+"\n";
        }

        dip_tv.setText(CurData);
    }

Answer 3

我得到了答案，实际上我错过了timeSwapBuff的概念：

所以这里是秒表的更正代码

public class StopwatchFragment extends Fragment implements View.OnClickListener {
public static StopwatchFragment newInstance() {
    StopwatchFragment fragment = new StopwatchFragment();
    return fragment;
}
FloatingActionButton stopwatchButton;
ImageView stopwatchReplayButton, stopwatchShareButton;
TextView timerValue;
private long startTime=0L;
long timeInMilliSec= 0L;
long timeSwapBuff=0L;
long updatedTime=0L;
int secs, mins, millisec;

public SharedPreferences pref;
public static SharedPreferences.Editor editor;



private Handler customHandler= new Handler();

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);




}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {


    View view = inflater.inflate(R.layout.stopwatch, container, false);
    stopwatchButton=(FloatingActionButton) view.findViewById(R.id.stopwatchButton);
    stopwatchButton.setOnClickListener(this);

    timerValue=(TextView) view.findViewById(R.id.timerValue);

    pref=this.getActivity().getSharedPreferences("stopwatch", Context.MODE_PRIVATE);
    editor=pref.edit();
    timerValue.setText("" + pref.getInt("Key1",0) + " : " + String.format("%02d", pref.getInt("Key2",0)) + " : " + String.format("%03d", pref.getInt("Key3",3)));
    int a=pref.getInt("Key1",0);
    int b=pref.getInt("Key2",0);
    int c=pref.getInt("Key3",0);
    Time t=Time.valueOf(a +":"+b+":"+c);
    int mm=a*60000;
    mm=mm+b*1000;
    mm=mm+c;

    timeSwapBuff= new Long(mm);


    stopwatchReplayButton=(ImageView)view.findViewById(R.id.stopwatchReplayButton);
    stopwatchReplayButton.setOnClickListener(this);

    stopwatchShareButton=(ImageView)view.findViewById(R.id.stopwatchShareButton);
    stopwatchShareButton.setOnClickListener(this);

    return view;
}

@Override
public void onClick(View view) {

    if(view==stopwatchButton)
    {
        if(stopwatchButton.getTag().toString().equals("off"))
        {
            stopwatchButton.setTag("on");
            stopwatchButton.setImageResource(R.drawable.pause);
            startTime= SystemClock.uptimeMillis();
            customHandler.postDelayed(updateTimerThread,0);
            stopwatchReplayButton.setVisibility(View.VISIBLE);


        }
        else
        {
            stopwatchButton.setTag("off");
            stopwatchShareButton.setVisibility(View.VISIBLE);
            stopwatchButton.setImageResource(R.drawable.play);
            timeSwapBuff+=timeInMilliSec;
            customHandler.removeCallbacks(updateTimerThread);
        }
    }

    if(view==stopwatchReplayButton)
    {
        customHandler.removeCallbacks(updateTimerThread);
        timerValue.setText("0 : 00 : 00");
        stopwatchButton.setTag("off");
        stopwatchButton.setImageResource(R.drawable.play);
        timeInMilliSec= 0L;
        timeSwapBuff=0L;
        updatedTime=0L;
    }

    if(view==stopwatchShareButton)
    {
        String text="My Time is "+mins+" : "+secs+" : "+millisec;
        Intent i=new Intent(Intent.ACTION_SEND);
        i.setType("text/plain");
        i.putExtra(Intent.EXTRA_TEXT,text);
        startActivity(Intent.createChooser(i,"Share Using"));
    }

}
private Runnable updateTimerThread=new Runnable() {
    @Override
    public void run() {
        timeInMilliSec = SystemClock.uptimeMillis() - startTime;
        updatedTime = timeSwapBuff + timeInMilliSec;

        secs = (int) (updatedTime / 1000);
        mins = secs / 60;
        secs = secs % 60;
        millisec = (int) (updatedTime % 1000);
        timerValue.setText("" + mins + " : " + String.format("%02d", secs) + " : " + String.format("%03d", millisec));
        editor.putInt("Key1",mins);
        editor.putInt("Key2",secs);
        editor.putInt("Key3",millisec);
        customHandler.postDelayed(this, 0);
        editor.commit();
    }
};

}

秒表与共享偏好 - android

3 个答案: