Question

我是Android Studio的新手，我正在构建一个简单的倒数计时器应用程序。我有2个活动。用户通过日期选择器选择日期的第一个活动（登录），第二个活动（个人资料）显示倒数计时器。当我在java类中为它设置日期时，倒数计时器工作正常，但我在尝试从登录活动中检索日期时遇到了麻烦。我的这两项活动的代码如下。

我知道我必须改变Date futureDate = dateFormat.parse（“2016-8-10”）;但我不知道怎么做。

LOGIN.CLASS

public class Login extends AppCompatActivity implements DatePickerDialog.OnDateSetListener, OnClickListener {
//private SharedPreferences sp;

EditText enterusername;
Button continuetoprofile;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_login);
    /*sp = getSharedPreferences("myPreference" , Context.MODE_PRIVATE);
    SharedPreferences.Editor editor = sp.edit();
    editor.putString("myKey" , "I am data to store");
    editor.commit();

     Writing data to SharedPreferences*/

    enterusername = (EditText) findViewById(R.id.enterusername);
    continuetoprofile=(Button) findViewById(R.id.continuetoprofile);
    continuetoprofile.setOnClickListener(this);
}

//SHARED PREFERENCES
/*public void saveInfo(View view){
    SharedPreferences save = getSharedPreferences("name", Context.MODE_PRIVATE);

    SharedPreferences.Editor editor = save.edit();
    editor.putString("username",enterusername.getText().toString());
    editor.apply();
}*/



public void onClick (View v){
    Intent intent = new Intent(this,Profile.class);
    intent.putExtra("username", enterusername.getText().toString());
    startActivity(intent);
}
public void datePicker(View view){

    DatePickerFragment fragment = new DatePickerFragment();
    fragment.show(getSupportFragmentManager(), "date");
}
private void setDate(final Calendar calendar) {
    final DateFormat dateFormat = DateFormat.getDateInstance(DateFormat.MEDIUM);
    ((TextView) findViewById(R.id.showDate)).setText(dateFormat.format(calendar.getTime()));
}

public void onDateSet(DatePicker view, int year, int month, int day) {
    Calendar cal = new GregorianCalendar(year, month, day);
    setDate(cal);
}
public static class DatePickerFragment extends DialogFragment {
    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {
        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);
        return new DatePickerDialog(getActivity(),
                (DatePickerDialog.OnDateSetListener)
                        getActivity(), year, month, day);
    }

}
Intent intent = getIntent();
public void privPol(View view){
    Intent intent = new Intent(this, PrivacyPolicy.class);
    startActivity(intent);
}
public void TOU(View view){
    Intent intent = new Intent(this, TermsOfUse.class);
    startActivity(intent);
}
public void toProfile(View view){
    Intent intent = new Intent(this, Profile.class);
    startActivity(intent);

}

PROFILE.CLASS

public class Profile extends AppCompatActivity {
//private SharedPreferences spref;
//TextView nameofuser;

TextView nameofuser;
private TextView daystxt, hourstxt, minutestxt, secondstxt;
private Handler handler;
private Runnable runnable;

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

    initUI();
    countDownStart();

    nameofuser = (TextView)findViewById(R.id.nameofuser);
    Intent intent = getIntent();
    String username = intent.getStringExtra("username");
    nameofuser.setText("Welcome,  " + username);

}

@SuppressLint("SimpleDateFormat")
private void initUI() {
    daystxt = (TextView) findViewById(R.id.days);
    hourstxt = (TextView) findViewById(R.id.hours);
    minutestxt = (TextView) findViewById(R.id.minutes);
    secondstxt = (TextView) findViewById(R.id.seconds);
}
public void countDownStart() {
    handler = new Handler();
    runnable = new Runnable() {
        @Override
        public void run() {
            handler.postDelayed(this, 1000);
            try {
                SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd");

                // Here Set your Event Date
                Date futureDate = dateFormat.("2016-8-10");
                Date currentDate = new Date();
                if (!currentDate.after(futureDate)) {
                    long diff = futureDate.getTime()
                            - currentDate.getTime();
                    long days = diff / (24 * 60 * 60 * 1000);
                    diff -= days * (24 * 60 * 60 * 1000);
                    long hours = diff / (60 * 60 * 1000);
                    diff -= hours * (60 * 60 * 1000);
                    long minutes = diff / (60 * 1000);
                    diff -= minutes * (60 * 1000);
                    long seconds = diff / 1000;
                    daystxt.setText("" + String.format("%02d", days));
                    hourstxt.setText("" + String.format("%02d", hours));
                    minutestxt.setText("" + String.format("%02d", minutes));
                    secondstxt.setText("" + String.format("%02d", seconds));
                } else {
                    handler.removeCallbacks(runnable);
                    // handler.removeMessages(0);
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    };
    handler.postDelayed(runnable, 0);
}

Intent intent = getIntent();
public void toMenu(View view) {
    Intent intent = new Intent(this, Menu.class);
    startActivity(intent);
}
public void tostartdate(View view) {
    Intent intent = new Intent(this, EditStartdate.class);
    startActivity(intent);
}

Answer 1

    //Get the date 
Date buttonDate = SimpleDateFormat.getDateInstance().parse(mDate.getText().toString());

和

  //Create a bundle to pass the date and send your date as Long
            Bundle currentDate = new Bundle();
            currentDate.putLong("setDate", buttonDate.getTime());

和

 //Read the passed bundle from the next activity get Long and convert it to Date 
Bundle setDate = this.getArguments();
Long currDate = setDate.getLong("setDate");

注意： Date构造函数接受的时间长度以毫秒为单位，而不是秒。你需要将它乘以1000，并确保你提供它。

转换

Date d = new Date(1220227200L * 1000);

Answer 2

尝试使用putExtras（）方法将其传递给Bundle中的Intent。

以下代码将有所帮助：

通过捆绑包发送数据

Intent i = new Intent(this, ActivityTwo.class);

Bundle bundle = new Bundle();
bundle.putExtras("Date",YOUR_DATE);

i.putExtras(bundle);

startActivity(i);

在新活动中获取数据

Bundle bundle = getIntent().getExtras();

String date = bundle.getString(“Date”);

这将有助于

如何从datepicker获取日期到android中的另一个活动

2 个答案: