小秒表计时的功能实现

用DevEco工具

首先给main_layout.xml一个按钮一个文本

<?xml version="1.0" encoding="utf-8"?>
<DependentLayout
    xmlns:ohos="http://schemas.huawei.com/res/ohos"
    ohos:width="match_parent"
    ohos:height="match_parent"
    ohos:background_element="#000000">
    <TickTimer
        ohos:id="$+id:tick_timer"
        ohos:width="match_content"
        ohos:height="match_content"
        ohos:center_in_parent="true"
        ohos:text="00:00:00"
        ohos:text_color="#007DFF"
        ohos:text_size="32fp"/>
    <Button
        ohos:id="$+id:button"
        ohos:width="match_content"
        ohos:height="match_content"
        ohos:text_size="19fp"
        ohos:text="开始计时"
        ohos:top_padding="8vp"
        ohos:bottom_padding="8vp"
        ohos:right_padding="80vp"
        ohos:left_padding="80vp"
        ohos:background_element="$graphic:button_element"
        ohos:center_in_parent="true"
        ohos:align_parent_bottom="true"/>
</DependentLayout>

button_element.xml用来显示按钮的背景

<?xml version="1.0" encoding="utf-8"?>
<shape
    xmlns:ohos="http://schemas.huawei.com/res/ohos"
    ohos:shape="oval">
    <solid
        ohos:color="#007DFF"/>
</shape>

在实现功能之前先创建一个TimeFormat 的工具类

package com.example.myapplication3.slice;

public class TimeFormatUtil {
    public static String toDisplayString(int timeHundreds){
        int hundreds,seconds,minutes;

        String[] formatterArrayMillis = new String[2];
        String formattedSeconds,formattedMinutes;

        hundreds=timeHundreds%100;
        String milliSecStr = Integer.toString(hundreds);
        formatterArrayMillis[0] = "0" + milliSecStr;
        formatterArrayMillis[1] = milliSecStr;

        seconds=(timeHundreds/=100)%60;
        minutes=(timeHundreds/=60)%60;

        //format output
        formattedSeconds=Integer.toString(seconds/10)+
                Integer.toString(seconds%10);
        formattedMinutes=Integer.toString(minutes/10)+
                Integer.toString(minutes%10);

        int millSecDigitsCnt = milliSecStr.length();
        String timeString =
                formattedMinutes+":"+
                        formattedSeconds+"."+
                        formatterArrayMillis[millSecDigitsCnt - 1];

        return timeString;
    }
}

在mainability.java中加载Xml布局，并且 onStart()方法加入功能代码

package com.example.myapplication3;

import com.example.myapplication3.slice.MainAbilitySlice;
import com.example.myapplication3.slice.TimeFormatUtil;
import ohos.aafwk.ability.Ability;
import ohos.aafwk.content.Intent;
import ohos.agp.components.Button;
import ohos.agp.components.Component;
import ohos.agp.components.Text;
import ohos.app.dispatcher.TaskDispatcher;

import java.util.Timer;
import java.util.TimerTask;

public class MainAbility extends Ability {
    private Timer mTimer;
    private Boolean isButtonStartPressed = false;
    @Override
    public void onStart(Intent intent) {

        super.onStart(intent);
        super.setUIContent(ResourceTable.Layout_main_layout);
        Button mButton = (Button)  findComponentById(ResourceTable.Id_button);
        Text mText = (Text) findComponentById(ResourceTable.Id_tick_timer);
        TaskDispatcher uiTaskDispatcher = getUITaskDispatcher();

        if (mButton != null){
            // 为按钮设置点击回调
            mButton.setClickedListener(new Component.ClickedListener()
             {
                @Override
                public void onClick(Component component){

                    final int[] currentTime = {0};
                    if (isButtonStartPressed) {
                        System.out.println("停止计时！！！！！");
                        isButtonStartPressed = false;
                        uiTaskDispatcher.asyncDispatch(new Runnable() {
                            @Override
                            public  void  run() {
                                mButton.setText("开始计时");
                            }
                        });
                        mTimer.cancel();
                    }else {
                        System.out.println("开始计时！！！！！！！");
                        isButtonStartPressed = true;
                        mTimer = new Timer();
                        mTimer.scheduleAtFixedRate(new TimerTask() {
                            @Override
                            public void run(){
                                currentTime[0] += 1;
                                uiTaskDispatcher.asyncDispatch(new Runnable() {
                                    @Override
                                    public void run(){
                                        mText.setText(TimeFormatUtil.toDisplayString(currentTime[0]));
                                        mButton.setText("停止计时");
                                    }
                                });
                            }
                        }, 0, 10);
                    }
                }
            });
        }
    }
    @Override
    public void onActive() {
        super.onActive();
    }

    @Override
    public void onForeground(Intent intent) {
        super.onForeground(intent);
    }
}

选择Wearable

运行程序后如下

我们点击开始计时，表中数字部分开始运行

点击停止计时后，表中数字部分停止计时