Android應用程式中Timer元件的使用範例

以Timer元件做一個計時器來了解Timer的設計與應用

activity_main.xml：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity" >

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

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

        <TextView
            android:id="@+id/timer"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="00:00" />
    </LinearLayout>

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

        <Button
            android:id="@+id/start"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="開始" />

        <Button
            android:id="@+id/stop"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="停止" />
        
        <Button
            android:id="@+id/zero"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="歸零" />        
            
        <Button
            android:id="@+id/end"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="結束" />        
    </LinearLayout>

</LinearLayout>

MainActivity.java：

package com.example.timer;

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

import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;

public class MainActivity extends Activity {

	private TextView timer;
	private Button start;
	private Button stop;
	private Button zero;
	private Button end;
	private boolean startflag=false;
	private int tsec=0,csec=0,cmin=0;


	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		timer = (TextView)findViewById(R.id.timer);
		start = (Button)findViewById(R.id.start);
		stop = (Button)findViewById(R.id.stop);
		zero = (Button)findViewById(R.id.zero);
		end = (Button)findViewById(R.id.end);
		
		//宣告Timer
		Timer timer01 =new Timer();
		
		//設定Timer(task為執行內容，0代表立刻開始,間格1秒執行一次)
		timer01.schedule(task, 0,1000);

		//Button監聽
		start.setOnClickListener(listener);
		stop.setOnClickListener(listener);
		zero.setOnClickListener(listener);
		end.setOnClickListener(listener);
	}
	
	//TimerTask無法直接改變元件因此要透過Handler來當橋樑
	private Handler handler = new Handler(){
		 public  void  handleMessage(Message msg) {
			 super.handleMessage(msg);
			 switch(msg.what){
			 case 1:
		 csec=tsec%60;
		 cmin=tsec/60;
                 String s="";
                 if(cmin <10 s="<span" style="color: #2a00ff;">"0"
+cmin;
                 }else{
                     s=""+cmin;
                 }
                 if(csec < 10){
                     s=s+":0"+csec;
                 }else{
                     s=s+":"+csec;
                 }
                 
                 //s字串為00:00格式
                 timer.setText(s);
                 break;
             }
         }
    };
    
    private TimerTask task = new TimerTask(){

        @Override
        public void run() {
            // TODO Auto-generated method stub
            if (startflag){
                //如果startflag==true則每秒tsec+1
                tsec++;
                Message message = new Message();
                
                //傳送訊息1
                message.what =1;
                handler.sendMessage(message);
            }
        }
        
    };

    private OnClickListener listener =new OnClickListener(){

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
        switch(v.getId()){
        case R.id.start:
            startflag=true;
            break;
        case R.id.stop:
            startflag=false;
            break;
        case R.id.zero:
            tsec=0;
            //TextView 初始化
            timer.setText("00:00");
            break;
        case R.id.end:
            finish();
            break;
        }
        }
        
    };
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

}

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