如何在特定日期创建倒计时?

huangapple go评论60阅读模式
英文:

How do you create a coutdown on a specific date?

问题

如何在特定日期创建倒计时?

我想创建一个从当前日期倒数到特定日期的倒计时。
我还尝试了stackoverflow上的代码。然而,我得到了大量的天数或计时器不工作的问题。

我的TimeFragment.java

import android.os.Bundle;
import androidx.fragment.app.Fragment;
import android.os.CountDownTimer;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import com.kalirobot.daring.R;
import java.util.Calendar;
import java.util.concurrent.TimeUnit;

public class TimeFragment extends Fragment {

    private TextView timer;
    public static TimeFragment newInstance() {
        return new TimeFragment();
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_time, container, false);
        timer = view.findViewById(R.id.textView3);

        Calendar start_calendar = Calendar.getInstance();
        Calendar end_calendar = Calendar.getInstance();
        // end DAY
        end_calendar.set(2020, 8, 23);

        long start_millis = start_calendar.getTimeInMillis();
        long end_millis = end_calendar.getTimeInMillis();
        long total_millis = (end_millis - start_millis);

        CountDownTimer cdt = new CountDownTimer(total_millis, 1000) {
            @Override
            public void onTick(long millisUntilFinished) {
                long days = TimeUnit.MILLISECONDS.toDays(millisUntilFinished);
                millisUntilFinished -= TimeUnit.DAYS.toMillis(days);
                long hours = TimeUnit.MILLISECONDS.toHours(millisUntilFinished);
                millisUntilFinished -= TimeUnit.HOURS.toMillis(hours);
                long minutes = TimeUnit.MILLISECONDS.toMinutes(millisUntilFinished);
                millisUntilFinished -= TimeUnit.MINUTES.toMillis(minutes);
                long seconds = TimeUnit.MILLISECONDS.toSeconds(millisUntilFinished);
                timer.setText(days + ":" + hours + ":" + minutes + ":" + seconds);
            }

            @Override
            public void onFinish() {
                timer.setText("Finish!");
            }
        };
        cdt.start();
        return view;
    }
}

现在timer中的输出是51:23:59:41,而期望的"天"部分应该是21而不是51

提示 - 如果您想要一个带有同步时间的倒计时

GitHub

英文:

How do you create a coutdown on a specific date?

I want to create a countdown that counts down from the current date to a specific date.
I've also tried stackoverflow code. However, I had an exorbitant number of days or that the timer didn't work.

My TimeFragment.java

import android.os.Bundle;
import androidx.fragment.app.Fragment;
import android.os.CountDownTimer;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import com.kalirobot.daring.R;
import java.util.Calendar;
import java.util.concurrent.TimeUnit;


public class TimeFragment extends Fragment {

    private TextView timer;
    public static TimeFragment newInstance() {
        return new TimeFragment();
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_time, container, false);
        timer = view.findViewById(R.id.textView3);

        Calendar start_calendar = Calendar.getInstance();
        Calendar end_calendar = Calendar.getInstance();
        // end DAY
        end_calendar.set(2020, 8, 23);

        long start_millis = start_calendar.getTimeInMillis();
        long end_millis = end_calendar.getTimeInMillis();
        long total_millis = (end_millis - start_millis);


        CountDownTimer cdt = new CountDownTimer(total_millis, 1000) {
            @Override
            public void onTick(long millisUntilFinished) {
                long days = TimeUnit.MILLISECONDS.toDays(millisUntilFinished);
                millisUntilFinished -= TimeUnit.DAYS.toMillis(days);
                long hours = TimeUnit.MILLISECONDS.toHours(millisUntilFinished);
                millisUntilFinished -= TimeUnit.HOURS.toMillis(hours);
                long minutes = TimeUnit.MILLISECONDS.toMinutes(millisUntilFinished);
                millisUntilFinished -= TimeUnit.MINUTES.toMillis(minutes);
                long seconds = TimeUnit.MILLISECONDS.toSeconds(millisUntilFinished);
                timer.setText(days + ":" + hours + ":" + minutes + ":" + seconds);
            }

            @Override
            public void onFinish() {
                timer.setText("Finish!");
            }
        };
        cdt.start();
        return view;
    }
}

The output now is 51:23:59:41 in the timer while 21 would be the expected value for the "days" portion instead of 51.

Hint - If you want a countdown with synchronized time

GitHub

答案1

得分: 3

你的问题是8代表的不是八月,而是九月,而九月23日距今大约还有52天。月份是从0开始计数的。

解决方案:使用7代表八月。

参考:https://stackoverflow.com/a/344400/2442804,尝试解释为什么这样做。

英文:

Your problem is that 8 does not represent August but September, and the 23rd of September is more or less 52 days from now. The month is 0-indexed.

Solution: use 7 for August.

See e.g. https://stackoverflow.com/a/344400/2442804 for an attempt at explaining why.

huangapple
  • 本文由 发表于 2020年8月3日 02:12:10
  • 转载请务必保留本文链接:https://go.coder-hub.com/63219498.html
匿名

发表评论

匿名网友

:?: :razz: :sad: :evil: :!: :smile: :oops: :grin: :eek: :shock: :???: :cool: :lol: :mad: :twisted: :roll: :wink: :idea: :arrow: :neutral: :cry: :mrgreen:

确定