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我想我可能在一篇文章中问的太多了，所以让我知道我是否应该将它分解为日期和时间的单独问题，但是在数据库中使用日期和时间让我完全难过。我研究了各种方法（字符串、juliandates、unix 等），它所做的一切让我更加困惑。为了提供一些上下文，用户通过填写​​表格来添加记录。该表单有 2 个按钮，一个使用日期选择器打开一个片段，一个使用时间选择器打开一个片段。所选日期和时间显示为按钮文本。另一个按钮将表单详细信息保存到数据库中。

接下来，我有一个显示当前所有记录的列表视图活动，但我最终希望有一个指向日期选择器片段的按钮，以便只显示具有特定日期的记录。然后按时间顺序列出这些记录。（我想一旦解决了下一段，我就可以自己弄清楚这一段。）

单击列表视图中的一条记录会打开一个与原始表单（创建记录的位置）具有相同外观的活动，并填充该记录中的所有信息。然后用户可以选择删除记录，或修改记录中的字段并保存（更新）记录。此表单还应包含一个日期和时间按钮，以便也可以更改这些按钮，因此应将选择器设置为此活动中先前保存的日期/时间。

我需要帮助的是存储日期和时间以便稍后在编辑表单中检索和编辑它的最佳方法，包括将其格式化为特定方法以显示为按钮文本（日期的 DD/MM/yyyy和 hh:mm:am/pm 时间）。如前所述，这让我感到很困惑，所以我真的很感激能有这样的手把手。为下面的大量编码道歉，但我试图通过删除所有额外的表单字段来保持它的相关性。

FuncAdd.java（保存数据的表格）：

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

    now = Calendar.getInstance();
    add_button_date = (Button) findViewById(R.id.add_button_date);
    add_button_time = (Button) findViewById(R.id.add_button_time);

    add_button_date.setText(String.valueOf(now.get(Calendar.DAY_OF_MONTH))+"/"+
            String.valueOf(now.get(Calendar.MONTH)+1)+"/"+
            String.valueOf(now.get(Calendar.YEAR)));
    strDate = add_button_date.getText().toString();

    add_button_time.setText(String.valueOf(now.get(Calendar.HOUR_OF_DAY))+":"+
            String.valueOf(now.get(Calendar.MINUTE)));
}

public void addDateTime(View v) {
    int id = v.getId();
    switch (id) {
    case R.id.add_button_date :
        showDialogDate();
        break;
    case R.id.add_button_time :
        showDialogTime();
        break;
    default:
        break;
}}

public interface DateDialogFragmentListener {
    public void updateChangedDate(int year, int month, int day);
}

public interface TimeDialogFragmentListener {
    public void updateChangedTime(int hourOfDay, int minute);
}

public void showDialogDate() {
    FragmentTransaction ftDate = getFragmentManager().beginTransaction();
    fragDate = DateDialogFragment.newInstance(this, new DateDialogFragmentListener() {
        public void updateChangedDate(int year, int month, int day) {
            add_button_date.setText(String.valueOf(day)+"/"+String.valueOf(month+1)+"/"+String.valueOf(year));
            now.set(Calendar.YEAR, year);
            now.set(Calendar.MONTH, month);
            now.set(Calendar.DAY_OF_MONTH, day);
        }}, now);
    fragDate.show(ftDate, "DateDialogFragment");
}

public void showDialogTime() {
    FragmentTransaction ftTime = getFragmentManager().beginTransaction();
    fragTime = TimeDialogFragment.newInstance(this, new TimeDialogFragmentListener() {
        public void updateChangedTime(int hourOfDay, int minute) {
            add_button_time.setText(String.valueOf(hourOfDay)+":"+String.valueOf(minute));
            now.set(Calendar.HOUR_OF_DAY, hourOfDay);
            now.set(Calendar.MINUTE, minute);
        }}, now);
    fragTime.show(ftTime, "TimeDialogFragment");
}

public void onClick(View arg0) {

    strDate = add_button_date.getText().toString();
    strTime = add_button_time.getText().toString();

    String Time = strTime;
    String Date = strDate;
AddDBHelper entry = new AddDBHelper(FuncAdd.this);
    entry.open();
    entry.createEntry(Time, Date, Category, CategoryPos, BGL, Carbs, Insulin, InsulinPos, Dose, CorInsulin, CorInsulinPos, CorDose);
    entry.close();              

    goHome (this);
}

AddDBHelper.java（我的数据库助手类）：

private static class DbHelper extends SQLiteOpenHelper {

    public DbHelper(Context context) {
        super(context, DB_NAME, null, DB_VERSION);
    }


    @Override
    public void onCreate(SQLiteDatabase db) {
        db.execSQL("CREATE TABLE " + DB_TABLE + " (" +
            KEY_ROWID + " INTEGER PRIMARY KEY AUTOINCREMENT, " +
            KEY_TIME + " TEXT NOT NULL, " +
            KEY_DATE + " TEXT NOT NULL, " +
            KEY_CATEG + " TEXT NOT NULL);"
);}

public long createEntry(String Time, String Date, String Category) {
    ContentValues cv = new ContentValues();
    cv.put(KEY_TIME, Time);
    cv.put(KEY_DATE, Date);
    cv.put(KEY_CATEG, Category);
    return glucoDB.insert(DB_TABLE, null, cv);
}

public Cursor getEntries() {        
    return glucoDB.query(DB_TABLE, new String[] {
            KEY_ROWID,
            KEY_TIME,
            KEY_DATE,
            KEY_CATEG},
            null, null, null, null, null);
}

public void updateDetails(DBDetails dbdetails) {

    ContentValues cv = new ContentValues();
    cv.put(AddDBHelper.KEY_TIME, UpdateDBDetails.newTime);
    cv.put(AddDBHelper.KEY_DATE, UpdateDBDetails.newDate);
    cv.put(AddDBHelper.KEY_CATEG, dbdetails.getuCateg());

    int count = glucoDB.update(DB_TABLE, cv, KEY_ROWID + "=?", new String[] {String.valueOf(dbdetails.getuRow())});
    Log.v("AddDbHelper", "Row " + dbdetails.getuRow() + " updated? " + count);
}

* TimeDialogFragment 类：*

public class TimeDialogFragment extends DialogFragment {

static Context mContext;
static int mHour;
static int mMinute;
static TimeDialogFragmentListener mListener;

public static TimeDialogFragment newInstance(Context context,
        TimeDialogFragmentListener listener, Calendar now) {
    TimeDialogFragment dialog = new TimeDialogFragment();
    mContext = context;
    mListener = listener;

    mHour = now.get(Calendar.HOUR_OF_DAY);
    mMinute = now.get(Calendar.MINUTE);

    Bundle args = new Bundle();
    args.putString("title", "Set Time");
    dialog.setArguments(args);
    return dialog;
}

public Dialog onCreateDialog(Bundle savedInstanceState) {
    return new TimePickerDialog(mContext, mTimeSetListener, mHour, mMinute, false);
}

private TimePickerDialog.OnTimeSetListener mTimeSetListener =
        new TimePickerDialog.OnTimeSetListener() {

    public void onTimeSet(TimePicker view, int hourOfDay, int minute) {
        mHour = hourOfDay;
        mMinute = minute;
        mListener.updateChangedTime(hourOfDay, minute);
    }
}; }

DateDialogFragment 类：

public class DateDialogFragment extends DialogFragment {

static Context mContext;
static int mYear;
static int mMonth;
static int mDay;
static DateDialogFragmentListener mListener;

public static DateDialogFragment newInstance(Context context,
        DateDialogFragmentListener listener, Calendar now) {
    DateDialogFragment dialog = new DateDialogFragment();
    mContext = context;
    mListener = listener;

    mYear = now.get(Calendar.YEAR);
    mMonth = now.get(Calendar.MONTH);
    mDay = now.get(Calendar.DAY_OF_MONTH);

    Bundle args = new Bundle();
    args.putString("title", "Set Date");
    dialog.setArguments(args);
    return dialog;          
}

public Dialog onCreateDialog(Bundle savedInstanceState) {
    return new DatePickerDialog(mContext, mDateSetListener,
            mYear, mMonth, mDay);
}

private DatePickerDialog.OnDateSetListener mDateSetListener = 
        new DatePickerDialog.OnDateSetListener() {

    public void onDateSet(DatePicker view, int year, int monthOfYear,
            int dayOfMonth) {
        mYear = year;
        mMonth = monthOfYear;
        mDay = dayOfMonth;
        mListener.updateChangedDate(year, monthOfYear, dayOfMonth);     
            }
    };}

DBDetails.java（获取/设置值的类）：

public class DBDetails {

private String uRow;
private String uTime;
private String uDate;
private String uCateg;

public String getuRow() {
    return uRow;
}

public void setuRow(String uRow) {
    this.uRow = uRow;
}

public String getuTime() {
    return uTime;
}

public void setuTime(String uTime) {
    this.uTime = uTime;
}

public String getuDate() {
    return uDate;
}

public void setuDate(String uDate) {
    this.uDate = uDate;
}

public String getuCateg() {
    return uCateg;
}

public void setuCateg(String uCateg) {
    this.uCateg = uCateg;
} }

UpdateDBDetails.java（用户可以编辑记录的类）：

public class UpdateDBDetails extends DashMenuActivity {

TimeDialogFragment fraguTime;
DateDialogFragment fraguDate;
Button update_button_time, update_button_date;
Calendar now;

ImageButton update_button_save, update_button_delete;   
String strTime, strDate;

private String bundleduRowId;
private String bundleduTime;
private String bundleduDate;
private String bundleduCateg;
public static String getRowId;
public static String newTime, newDate, newCat;

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.updatedbdetails);

    now = Calendar.getInstance();
    update_button_date = (Button) findViewById(R.id.update_button_date);
    update_button_time = (Button) findViewById(R.id.update_button_time);

    update_button_date.setText(bundleduDate);
    update_button_time.setText(bundleduTime);

Bundle takeBundledData = getIntent().getExtras();

    bundleduRowId = takeBundledData.getString("clickeduRowId");
    bundleduTime = takeBundledData.getString("clickeduTime");
    bundleduDate = takeBundledData.getString("clickeduDate");
    bundleduCateg = takeBundledData.getString("clickeduCateg");
}
public void clickUpdateDelete(View v) {
    newTime = strTime;
    newDate = strDate;
    newCateg = newCat;

AddDBHelper modifyEntry = new AddDBHelper(this);
    modifyEntry.open();

    DBDetails dbdetails = new DBDetails();

    dbdetails.setuRow(bundleduRowId);

    if (v.getId() == R.id.update_button_delete) {
        modifyEntry.deleteDetails(dbdetails);
    } else if (v.getId() == R.id.update_button_save) {
        dbdetails.setuDate(newDate);
        dbdetails.setuTime(newTime);
        dbdetails.setuCateg(newCateg);
modifyEntry.updateDetails(dbdetails);
    }   
    modifyEntry.close();
    finish();
}

FuncAdd.java 类的修正

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView (R.layout.dash_add);

    add_button_date = (Button) findViewById(R.id.add_button_date);
    add_button_time = (Button) findViewById(R.id.add_button_time);

    now = Calendar.getInstance().getTime();

    SimpleDateFormat dFormatter = new SimpleDateFormat("dd MMM yyyy");
    strDate = dFormatter.format(now);
    add_button_date.setText(strDate);

    SimpleDateFormat tFormatter = new SimpleDateFormat("KK:mm a");
    strTime = tFormatter.format(now);
    add_button_time.setText(strTime);
}

public interface DateDialogFragmentListener {
    public void updateChangedDate(int year, int month, int day);
}

public void showDialogDate() {
    FragmentTransaction ftDate = getFragmentManager().beginTransaction();
    fragDate = DateDialogFragment.newInstance(this, new DateDialogFragmentListener() {
        public void updateChangedDate(int year, int month, int day) {
            strDate = (String.valueOf(day)+"/"+String.valueOf(month+1)+"/"+String.valueOf(year));
            SimpleDateFormat dFormatter = new SimpleDateFormat("dd MMM yyyy");
            newstrDate = dFormatter.parse(strDate);
            add_button_date.setText(newstrDate);
        }}, now);
    fragDate.show(ftDate, "DateDialogFragment");
}

UpdateDBDetails.java 的修正

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.updatedbdetails);

Bundle takeBundledData = getIntent().getExtras();

    bundleduRowId = takeBundledData.getString("clickeduRowId");
    bundleduTime = takeBundledData.getString("clickeduTime");
    bundleduDate = takeBundledData.getString("clickeduDate");

SimpleDateFormat dFormatter = new SimpleDateFormat("dd MMM yyyy");
    SimpleDateFormat tFormatter = new SimpleDateFormat("KK:mm a");

    now = Calendar.getInstance();

// no need to catch an exception, as I'm using pickers and the format can never be input incorrectly
    try {
        dDate = dFormatter.parse(bundleduDate);
        String dateArray[] = dDate.toString().split(" ");

        if (dateArray[1].equalsIgnoreCase("Jan")) {
            uMonth = 0;
        } else if (dateArray[1].equalsIgnoreCase("Feb")) {
            uMonth = 1;
        } else if (dateArray[1].equalsIgnoreCase("Mar")) {
            uMonth = 2;
        } else if (dateArray[1].equalsIgnoreCase("Apr")) {
            uMonth = 3;
        } else if (dateArray[1].equalsIgnoreCase("May")) {
            uMonth = 4;
        } else if (dateArray[1].equalsIgnoreCase("Jun")) {
            uMonth = 5;
        } else if (dateArray[1].equalsIgnoreCase("Jul")) {
            uMonth = 6;
        } else if (dateArray[1].equalsIgnoreCase("Aug")) {
            uMonth = 7;
        } else if (dateArray[1].equalsIgnoreCase("Sep")) {
            uMonth = 8;
        } else if (dateArray[1].equalsIgnoreCase("Oct")) {
            uMonth = 9;
        } else if (dateArray[1].equalsIgnoreCase("Nov")) {
            uMonth = 10;
        } else if (dateArray[1].equalsIgnoreCase("Dec")) {
            uMonth = 11;
        } 

        int uYear = Integer.parseInt(dateArray[5]);
        int uDay = Integer.parseInt(dateArray[2]);
        now.set(Calendar.YEAR, uYear);
        now.set(Calendar.MONTH, uMonth);
        now.set(Calendar.DAY_OF_MONTH, uDay);
        CurrentD = now.getTime();
        strDate = dFormatter.format(CurrentD);
        update_button_date.setText(strDate);
    } catch (ParseException e) {
        e.printStackTrace();
    }

    try {
        tDate = tFormatter.parse(bundleduTime);
        String timeArrayFull[] = tDate.toString().split(" ");
        String timeArray[] = timeArrayFull[3].split(":");
        int uHour = Integer.parseInt(timeArray[0]);
        int uMinute = Integer.parseInt(timeArray[1]);
        now.set(Calendar.HOUR_OF_DAY, uHour);
        now.set(Calendar.MINUTE, uMinute);
        CurrentT = now.getTime();
        strTime = tFormatter.format(CurrentT);
        update_button_time.setText(strTime);
    } catch (ParseException e) {
        e.printStackTrace();
    }
\\ The rest of the code does not differ from above, for launching a dialogfragment and saving the results to the DB.
4

2 回答 2

1

嗯，我真的不明白为什么它让你难住了。但是我想如果您是关系数据库的新手，那么初学者会遇到一个可以理解的问题。存储日期和时间的最佳方法是采用大多数数据库易于理解的格式，即使您不打算导出它。查看SQLite网站。为了简短起见，只需将它们作为字符串以YYYY-MM-DD（日期）和HH:MM:SS（时间）格式存储在数据库中。然后，您可以使用 SQLite 的甜蜜内置函数，您可以在我提供的链接上看到这些函数 :) 希望它有所帮助。

编辑：

我还进行了一些额外的挖掘，因为我注意到我的应用程序实际上将日期和时间存储为 INTEGER 值，查看 SQLite 中的不同数据类型，但对你来说更重要的是，第 1.2 节关于日期和时间数据类型。因此，将它们保持为TEXT或INTEGER很好，只要保持一致即可。

于 2012-08-04T06:46:06.707 回答
0

使用 Chintan 建议的格式化程序，并阅读更多内容，我设法弄清楚了。安迪，你的建议很有价值，但我在如何使用对话框片段设置/获取数据以允许保存、检索和更新数据库方面获得了更多帮助。最后，我只需要修改我的主表单活动。

public class FuncAdd extends DashMenuActivity implements OnClickListener {

TimeDialogFragment fragTime;
DateDialogFragment fragDate;
Button add_button_time, add_button_date;
Calendar now;
Date nowDT, newD, newT;

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView (R.layout.dash_add);

    add_button_date = (Button) findViewById(R.id.add_button_date);
    add_button_time = (Button) findViewById(R.id.add_button_time);

    now = Calendar.getInstance();
    nowDT = now.getTime();

    SimpleDateFormat dFormatter = new SimpleDateFormat("dd MMM yyyy");
    strDate = dFormatter.format(nowDT);
    add_button_date.setText(strDate);

    SimpleDateFormat tFormatter = new SimpleDateFormat("KK:mm a");
    strTime = tFormatter.format(nowDT);
    add_button_time.setText(strTime);
}

public void addDateTime(View v) {
    int id = v.getId();
    switch (id) {
    case R.id.add_button_date :
        showDialogDate();
        break;
    case R.id.add_button_time :
        showDialogTime();
        break;
    default:
        break;
}}

public interface DateDialogFragmentListener {
    public void updateChangedDate(int year, int month, int day);
}

public interface TimeDialogFragmentListener {
    public void updateChangedTime(int hourOfDay, int minute);
}

public void showDialogDate() {
    FragmentTransaction ftDate = getFragmentManager().beginTransaction();
    fragDate = DateDialogFragment.newInstance(this, new DateDialogFragmentListener() {
        public void updateChangedDate(int year, int month, int day) {               
            now.set(Calendar.YEAR, year);
            now.set(Calendar.MONTH, month);
            now.set(Calendar.DAY_OF_MONTH, day);
            newD = now.getTime();
            SimpleDateFormat newDFormatter = new SimpleDateFormat("dd MMM yyyy");
            strDate = newDFormatter.format(newD);
            add_button_date.setText(strDate);
        }}, now);
    fragDate.show(ftDate, "DateDialogFragment");
}

public void showDialogTime() {
    FragmentTransaction ftTime = getFragmentManager().beginTransaction();
    fragTime = TimeDialogFragment.newInstance(this, new TimeDialogFragmentListener() {
        public void updateChangedTime(int hourOfDay, int minute) {
            now.set(Calendar.HOUR_OF_DAY, hourOfDay);
            now.set(Calendar.MINUTE, minute);
            newT = now.getTime();
            SimpleDateFormat tFormatter = new SimpleDateFormat("KK:mm a");
            strTime = tFormatter.format(newT);
            add_button_time.setText(strTime);
        }}, now);
    fragTime.show(ftTime, "TimeDialogFragment");
}
}
于 2012-08-04T12:36:00.987 回答