java - 如何在指定日期之前在Android中设置通知

Question

我正在制作一个应用程序，用户可以在其中为 friend 的生日设置提醒，但我一直坚持将日期类型存储在数据库中，并且还设置了一个通知，正如我在标题中所说，在指定日期之前日期。

我该怎么做？

这是我的代码，我只是在文本按钮上显示用户选择的日期，但我想存储该日期并在该特定日期前 2-3 周设置通知。

这是我的代码:

@SuppressLint("ValidFragment")
public class DatePickerFragment extends DialogFragment
        implements DatePickerDialog.OnDateSetListener {

    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {
        // Use the current date as the default date in the picker
        final Calendar c = Calendar.getInstance();
        int year = c.get(Calendar.YEAR);
        int month = c.get(Calendar.MONTH);
        int day = c.get(Calendar.DAY_OF_MONTH);

        // Create a new instance of DatePickerDialog and return it
        return new DatePickerDialog(getActivity(), this, year, month, day);
    }

    @Override
    public void onDateSet(DatePicker view, int year, int monthOfYear, int dayOfMonth) {
        mYear = year;
        mMonth = monthOfYear;
        mDay = dayOfMonth;

        // set selected date in button
        addBirthdayDate.setText(new StringBuilder().append(mMonth + 1)
        .append("-").append(mDay).append("-").append(mYear)
        .append("-"));
    }
}

还有数据库代码(我已经在数据库中尝试了一些东西，但我不太确定我在那里做什么)。所以我很感激这里的任何帮助:

public class DBHelper extends SQLiteOpenHelper {

private static final int DATABASE_VERSION = 5;
private static final String DATABASE_NAME = "_database";

private static final String BIRTHDAY_TABLE_NAME = "birthday_table";
public static final String BIRTHDAY_ID = "birthday_id";
public static final String BIRTHDAY_NAME = "birthday_name";
public static final String BIRTHDAY_LAST_NAME = "birthday_last_name";
public static final String BIRTHDAY_GENDER = "birthday_gender";
public static final String BIRTHDAY_AGE = "birthday_age";
public static final String BIRTHDAY_DATE = "birthday_date";

private static final String CREATE_TABLE = "CREATE TABLE " + BIRTHDAY_TABLE_NAME + " ( "
        + BIRTHDAY_ID + " INTEGER PRIMARY KEY,"
        + BIRTHDAY_NAME + " TEXT,"
        + BIRTHDAY_LAST_NAME + " TEXT,"
        + BIRTHDAY_GENDER + " TEXT,"
        + BIRTHDAY_DATE + " DATETIME,"
        + BIRTHDAY_AGE + " INTEGER );";

SQLiteDatabase database;

public DBHelper(Context context) {
    super(context, DATABASE_NAME, null, DATABASE_VERSION);
}

@Override
public void onCreate(SQLiteDatabase db) {
    db.execSQL(CREATE_TABLE);
}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    db.execSQL("DROP TABLE IF EXISTS " + BIRTHDAY_TABLE_NAME);
    onCreate(db);
}

public String getDateTime() {
    SimpleDateFormat dateFormat = new SimpleDateFormat(
            "yyyy-MM-dd HH:mm:ss", Locale.getDefault());
    Date date = new Date();
    return dateFormat.format(date);
}

public void setBirthdayData(String birthdayName, String birthdayLastName, String birthdayGender
,int age) {
    database = getWritableDatabase();
    ContentValues cv = new ContentValues();
    cv.put(BIRTHDAY_NAME, birthdayName);
    cv.put(BIRTHDAY_LAST_NAME, birthdayLastName);
    cv.put(BIRTHDAY_GENDER, birthdayGender);
    cv.put(BIRTHDAY_AGE, age);
    cv.put(BIRTHDAY_DATE, getDateTime());
    database.insert(BIRTHDAY_TABLE_NAME, null, cv);
}

Answer 1

如果你还有这个顾虑，我觉得没有必要存入数据库。只需将它存储在一个变量中，为您想要的任何时刻设置一个警报管理器，如果您不再需要通知，您可以将其删除。

如果您仍想在数据库中存储日期时间，我建议将它们存储为整数。这是我如何在我的应用程序中存储时间戳的示例:

private static final String CREATE_TABLE_NOTE = "create table "
        + Constants.NOTES_TABLE
        + "("
        + Constants.COL_ID + " integer primary key autoincrement, "
        + Constants.COL_TITLE + " text not null, "
        + Constants.COL_CONTENT + " text, "
        + Constants.COL_TYPE + " text not null, "
        + Constants.COL_CATID + " integer not null, "
        + Constants.COL_CREATED_TIME + " integer not null, "
        + Constants.COL_MODIFIED_TIME + " integer not null "
        + ")";