java - 倒计时器同时运行而不是连续运行

Question

我正在尝试制作一个应用程序，您可以在其中输入 session 的长度和 session 的数量，然后对 session 的长度进行倒计时，发出蜂鸣声，然后如果仍有 session ，则自动开始新的倒计时，但是此时，应用程序会同时开始所有倒计时。

因此，如果有 3 个 session ，每个 session 时长为 30 秒，则计数器会每秒减少 3 个值，从 30 减少到 -60。

在这种情况下，我试图让它做的是从 30 到 0 开始倒计时，发出蜂鸣声，然后从 30 到 0 蜂鸣声开始第二次倒计时，然后开始从 30 到 0 的第三次倒计时。

这是 manActivity.Java

package uk.co.test.fitnesstimer;

import android.content.Context;
import android.media.AudioManager;
import android.media.ToneGenerator;
import android.os.Bundle;
import android.os.CountDownTimer;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

import static uk.co.test.fitnesstimer.R.id.countdownTimer;
import static uk.co.test.fitnesstimer.R.id.session_length;


public class MainActivity extends AppCompatActivity {
    public int counter;
    public int sessionsLeft;
    Button button;
    TextView textView;
    public int lengthOfActivities = 30;
    public int numOfActivities = 1;
    public int isActive = 0;

    public void increment(View view) {
        lengthOfActivities++;
        display(lengthOfActivities);
    }

    public void decrement(View view) {
        if (lengthOfActivities > 1) {
            lengthOfActivities--;
        }
        display(lengthOfActivities);
    }

    public void incrementNumOfActivities(View view) {
        numOfActivities++;
        displayNum(numOfActivities);
    }

    public void decrementNumOfActivities(View view) {
        if (numOfActivities > 1) {
            numOfActivities--;
        }
        displayNum(numOfActivities);
    }

    private void display(int number) {
        TextView quantityTextView = (TextView) findViewById(R.id.session_length);
        quantityTextView.setText(String.valueOf(number));

    }

    private void displayNum(int number) {
        TextView quantityTextView = (TextView) findViewById(R.id.numOfActivities);
        quantityTextView.setText(String.valueOf(number));

    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        button = (Button) findViewById(R.id.button);
        textView = (TextView) findViewById(countdownTimer);
        button.setOnClickListener(new View.OnClickListener()
        {
            @Override
            public void onClick(View v) {
                if (isActive == 0){
                    isActive = 1;
                    sessionsLeft = numOfActivities;
                    counter = lengthOfActivities;
                    while (sessionsLeft > 0) {
                        new CountDownTimer((lengthOfActivities * 1000), 1000){
                            public void onTick(long millisUntilFinished){
                                textView.setText(String.valueOf(counter));
                                //if (counter > 0) {
                                    counter = counter - 1;
                                //}
                            }
                            public  void onFinish(){
                                textView.setText("FINISH!!");
                                ToneGenerator toneGen1 = new ToneGenerator(AudioManager.STREAM_MUSIC, 100);
                                toneGen1.startTone(ToneGenerator.TONE_CDMA_PIP,150);
                                isActive = 0;
                            }
                        }.start();
                        sessionsLeft--;
                    }
                }
                else {
                    Context context = getApplicationContext();
                    CharSequence text = "Timer is running already!";
                    int duration = Toast.LENGTH_SHORT;
                    Toast toast = Toast.makeText(context, text, duration);
                    toast.show();
                }

            }
        });
    }
}

这是 ActivityMain XML

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:padding="16dp"
    tools:context="uk.co.test.fitnesstimer.MainActivity">

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Length Of Sessions:"
        android:textAllCaps="true" />

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <Button
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:text="-"
            android:layout_weight="1"
            android:onClick="decrement" />

        <TextView
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:id="@+id/session_length"
            android:text="30"
            android:gravity="center"
            android:layout_weight="1" />

        <Button
            android:layout_width="1dp"
            android:layout_height="wrap_content"
            android:text="+"
            android:onClick="increment"
            android:layout_weight="1" />

    </LinearLayout>

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Number Of Sessions:"
        android:textAllCaps="true" />

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <Button
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:text="-"
            android:layout_weight="1"
            android:onClick="decrementNumOfActivities" />

        <TextView
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:id="@+id/numOfActivities"
            android:layout_weight="1"

            android:gravity="center"
            android:text="1" />

        <Button
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:text="+"
            android:layout_weight="1"
            android:onClick="incrementNumOfActivities" />

    </LinearLayout>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal">

        <Button
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:text="Start"
            android:id="@+id/button"
            android:onClick="submitOrder"
            android:layout_weight="1" />

     </LinearLayout>

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text=""
        android:id="@+id/countdownTimer" />

</LinearLayout>

Answer 1

如果你想连续调用倒计时，你应该编写一个递归函数而不是 while .. 它会在每次倒计时后调用自己

将您在 onClick 中编写的所有逻辑放入一个函数中，并使其递归调用自身，直到所有 session 完成。

 private void countDown()
{
    counter = lengthOfActivities;
    if (sessionsLeft > 0) {
        new CountDownTimer((lengthOfActivities * 1000), 1000)
        {
            public void onTick(long millisUntilFinished){
                textView.setText(String.valueOf(counter));
                counter = counter - 1;
            }
            public  void onFinish(){
                textView.setText("FINISH!!");
                ToneGenerator toneGen1 = new ToneGenerator(AudioManager.STREAM_MUSIC, 100);
                toneGen1.startTone(ToneGenerator.TONE_CDMA_PIP,150);
                isActive = 0;
                sessionsLeft--;
                countDown();
            }
        }.start();
    }
}

//在onclick中

if (isActive == 0){
                isActive = 1;
                sessionsLeft = numOfActivities;
                countDown();
            }