Android实现秒表计时器的程序设计

这是学习Android来第一个完整的Android程序。

主要功能是实现秒表计时，功能简介如下：

简介：计时器小程序——秒表计时器，程序界面简洁，只有一个时间显示区域和两个图片按钮，一个按钮是开始/暂停，另一个按钮是停止。

1.功能：

(1)根据用户设置.按0.1秒或1秒为最小单位计时，满60秒进为分钟，最大单位是分钟。

默认分钟为两位，超过两位后自动变为三位分钟。

(2).显示格式为

1.最小计时单位为0.1秒时，显示为：分钟：秒：0.1秒。例如：02:07:5

2.最小计时单位为1秒时，显示为：分钟：秒。例如：02:07

2.操作步骤

(1).按开始按钮，开始计时，此时开始按钮变为暂停按钮

(2).按暂停按钮，暂停计时，显示当前的计时时间

(3).按停止按钮，停止计时，暂停按钮恢复为开始按钮，时间显示为：00:00:00

(4)按menu键弹出menu菜单，第一项为设置计时单位，含有子菜单，可以设置计时单位为1秒或者为0.1秒。

画面显示如下所示：

2.计时单位设置子菜单

主要代码如下：

1.MyTimer.java

package com.min;

import java.io.ByteArrayOutputStream;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.Timer;
import java.util.TimerTask;

import android.app.Activity;
import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.util.Log;
import android.view.KeyEvent;
import android.view.Menu;
import android.view.MenuItem;
import android.view.SubMenu;
import android.view.View;
import android.widget.ImageButton;
import android.widget.TextView;

public class MyTimer extends Activity {
	private long mlCount = 0;
	private long mlTimerUnit = 100;
	private TextView tvTime;
	private ImageButton btnStartPause;
	private ImageButton btnStop;
	private Timer timer = null;
	private TimerTask task = null;
	private Handler handler = null;
	private Message msg = null;
	private boolean bIsRunningFlg = false;
	private static final String MYTIMER_TAG = "MYTIMER_LOG"; 
	
	// menu item
	private static final int SETTING_TIMER_UNIT_ID = Menu.FIRST;
	private static final int ABOUT_ID = Menu.FIRST + 1;
	private static final int EXIT_ID = Menu.FIRST + 2;
	private static final int SETTING_SECOND_ID = Menu.FIRST + 101;
	private static final int SETTING_100MILLISECOND_ID = Menu.FIRST + 102;
	
	// Setting timer unit flag
	private int settingTimerUnitFlg = SETTING_100MILLISECOND_ID;
	
	
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        tvTime = (TextView)findViewById(R.id.tvTime);
        btnStartPause = (ImageButton)findViewById(R.id.btnStartPaunse);
        btnStop = (ImageButton)findViewById(R.id.btnStop);
        
        SharedPreferences sharedPreferences = getSharedPreferences("mytimer_unit", Context.MODE_PRIVATE);
        //getString()第二个参数为缺省值，如果preference中不存在该key，将返回缺省值
        mlTimerUnit = sharedPreferences.getLong("time_unit", 100);
        Log.i(MYTIMER_TAG, "mlTimerUnit = " + mlTimerUnit);
        
        if (1000 == mlTimerUnit) {
        	// second
        	settingTimerUnitFlg = SETTING_SECOND_ID;
			tvTime.setText(R.string.init_time_second);
        } else if (100 == mlTimerUnit) {
			// 100 millisecond
        	settingTimerUnitFlg = SETTING_100MILLISECOND_ID;
			tvTime.setText(R.string.init_time_100millisecond);
        }
        
        // Handle timer message
        handler = new Handler(){
    		@Override
    		public void handleMessage(Message msg) {
    			// TODO Auto-generated method stub
    			switch(msg.what) {
    			case 1:
    				mlCount++;
    				int totalSec = 0;
    				int yushu = 0;
    				
    				if (SETTING_SECOND_ID == settingTimerUnitFlg) {
						// second
    					totalSec = (int)(mlCount);
					} else if (SETTING_100MILLISECOND_ID == settingTimerUnitFlg) {
						// 100 millisecond
						totalSec = (int)(mlCount / 10);
        				yushu = (int)(mlCount % 10);
					}
    				
    				// Set time display
    				int min = (totalSec / 60);
    				int sec = (totalSec % 60);
    				try{
    					if (SETTING_SECOND_ID == settingTimerUnitFlg) {
    						// second(1000ms)
    						tvTime.setText(String.format("%1$02d:%2$02d", min, sec));
    					} else if (SETTING_100MILLISECOND_ID == settingTimerUnitFlg) {
    						// 100 millisecond
    						tvTime.setText(String.format("%1$02d:%2$02d:%3$d", min, sec, yushu));
    					}
    				} catch(Exception e) {
    					tvTime.setText("" + min + ":" + sec + ":" + yushu);
    					e.printStackTrace();
    					Log.e("MyTimer onCreate", "Format string error.");
    				}
    				break;
    				
    			default:
    				break;
    			}
    			
    			super.handleMessage(msg);
    		}
    		
    	};
    	
        btnStartPause.setOnClickListener(startPauseListener);
        btnStop.setOnClickListener(stopListener);
    }
    
    // Start and pause
    View.OnClickListener startPauseListener = new View.OnClickListener() {

		@Override
		public void onClick(View v) {
			// TODO Auto-generated method stub
			Log.i(MYTIMER_TAG, "Start/Pause is clicked.");
			
			if (null == timer) {
				if (null == task) {
					task = new TimerTask() {
	
						@Override
						public void run() {
							// TODO Auto-generated method stub
							if (null == msg) {
								msg = new Message();
							} else {
								msg = Message.obtain();
							}
							msg.what = 1;
							handler.sendMessage(msg);
						}
						
					};
				}
				
				timer = new Timer(true);
				timer.schedule(task, mlTimerUnit, mlTimerUnit); // set timer duration
			}
			
			// start
			if (!bIsRunningFlg) {
				bIsRunningFlg = true;
				btnStartPause.setImageResource(R.drawable.pause);
			} else { // pause
				try{
					bIsRunningFlg = false;
					task.cancel();
					task = null;
					timer.cancel(); // Cancel timer
					timer.purge();
					timer = null;
					handler.removeMessages(msg.what);
					btnStartPause.setImageResource(R.drawable.start);
				} catch(Exception e) {
					e.printStackTrace();
				}
			}
		}
    	
    };
    
    // Stop
    View.OnClickListener stopListener = new View.OnClickListener() {

		@Override
		public void onClick(View v) {
			// TODO Auto-generated method stub
			Log.i(MYTIMER_TAG, "Stop is clicked.");
			
			if (null != timer) {
				task.cancel();
				task = null;
				timer.cancel(); // Cancel timer
				timer.purge();
				timer = null;
				handler.removeMessages(msg.what);
			}
			
			mlCount = 0;
			bIsRunningFlg = false;
			btnStartPause.setImageResource(R.drawable.start);
			
			if (SETTING_SECOND_ID == settingTimerUnitFlg) {
				// second
				tvTime.setText(R.string.init_time_second);
			} else if (SETTING_100MILLISECOND_ID == settingTimerUnitFlg) {
				// 100 millisecond
				tvTime.setText(R.string.init_time_100millisecond);
			}
		}
    	
    };
    
    
    // Menu
    @Override
	public boolean onCreateOptionsMenu(android.view.Menu menu) {
		// TODO Auto-generated method stub
		super.onCreateOptionsMenu(menu);
		
		Log.i(MYTIMER_TAG, "Menu is created.");
		
		// Stop timer
		if (null != task) {
			task.cancel();
			task = null;
		}
		if (null != timer) {
			timer.cancel(); // Cancel timer
			timer.purge();
			timer = null;
			handler.removeMessages(msg.what);
		}
		
		bIsRunningFlg = false;
		mlCount = 0;
		btnStartPause.setImageResource(R.drawable.start);
		
		// 设置子菜单的名称 
		SubMenu settingMenu = menu.addSubMenu(0, SETTING_TIMER_UNIT_ID, 0, R.string.menu_setting_timer_unit).setIcon(R.drawable.setting);
		
		// 按对应的名称增加子菜单
		// Sub menus do not support item icons, or nested sub menus.
		settingMenu.add(1, SETTING_SECOND_ID, 0, R.string.menu_setting_second);  
		settingMenu.add(1, SETTING_100MILLISECOND_ID, 1, R.string.menu_setting_100milisec);  
		
		// About
		menu.add(0, ABOUT_ID, 1, R.string.menu_about).setIcon(R.drawable.about);
		
		// 退出
		menu.add(0, EXIT_ID, 2, R.string.menu_exit).setIcon(R.drawable.exit);
		
		return true;
	}

    // Menu item
	@Override
	public boolean onOptionsItemSelected(MenuItem item) {
		// TODO Auto-generated method stub
		Log.i(MYTIMER_TAG, "Menu item is selected.");
	
		switch(item.getItemId()) {
			case SETTING_TIMER_UNIT_ID:
				break;
			
			case ABOUT_ID:
				// Display about dialog
				AlertDialog.Builder builder = new AlertDialog.Builder(this);
				builder.setTitle(R.string.app_name)
					   .setMessage("本程序由雨梦开发/n联系作者:[e-mail]")
				       .setCancelable(true)
				       .setPositiveButton("确定", new DialogInterface.OnClickListener() {
				           public void onClick(DialogInterface dialog, int id) {
				        	   dialog.cancel();
				           }
				       });
				AlertDialog alert = builder.create();
				alert.show();
				break;
				
			case EXIT_ID:
				finish(); // Exit application
				break;
				
			case SETTING_SECOND_ID: // 秒(1000ms)
				if (SETTING_SECOND_ID != settingTimerUnitFlg) {
					mlTimerUnit = 1000;
					settingTimerUnitFlg = SETTING_SECOND_ID;
				}
				tvTime.setText(R.string.init_time_second);
				break;
				
			case SETTING_100MILLISECOND_ID: // 100毫秒
				if (SETTING_100MILLISECOND_ID != settingTimerUnitFlg) {
					mlTimerUnit = 100;
					settingTimerUnitFlg = SETTING_100MILLISECOND_ID;
				}
				tvTime.setText(R.string.init_time_100millisecond);
				break;
				
			default:
				Log.i(MYTIMER_TAG, "Other menu item...");
				break;
		}
		
		// Save timer unit
		try{
			SharedPreferences sharedPreferences = getSharedPreferences("mytimer_unit", Context.MODE_PRIVATE);
			SharedPreferences.Editor editor = sharedPreferences.edit();//获取编辑器
			editor.putLong("time_unit", mlTimerUnit);
			editor.commit();//提交修改
		} catch(Exception e) {
			e.printStackTrace();
			Log.e(MYTIMER_TAG, "save timer unit error.");
		}
		
        
		return super.onOptionsItemSelected(item);
	}
	
	
	@Override
	public boolean onKeyDown(int keyCode, KeyEvent event) {
		// TODO Auto-generated method stub
		if (KeyEvent.KEYCODE_MENU == keyCode) {
			super.openOptionsMenu();  // 调用这个，就可以弹出菜单

			Log.i(MYTIMER_TAG, "Menu key is clicked.");
				
			// Stop timer
			if (null != task) {
				task.cancel();
				task = null;
			}
			if (null != timer) {
				timer.cancel(); // Cancel timer
				timer.purge();
				timer = null;
				handler.removeMessages(msg.what);
			}
			
			bIsRunningFlg = false;
			mlCount = 0;
			btnStartPause.setImageResource(R.drawable.start);
			
			return true;
		}
		
		return super.onKeyDown(keyCode, event);
	}

}

2.main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
    <TextView  
	    android:layout_width="wrap_content" 
	    android:layout_height="wrap_content"
	    android:text=" "
	    />
	<TextView  
	    android:layout_width="fill_parent" 
	    android:layout_height="wrap_content"
	    android:textSize="80sp"
	    android:gravity="center"
	    android:text="@string/init_time_100millisecond"
	    android:id="@+id/tvTime"
	    />
  
  	<TextView  
	    android:layout_width="wrap_content" 
	    android:layout_height="wrap_content"
	    android:text=" "
	    />
	    
    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
	    android:orientation="horizontal"
	    android:gravity="center"
	    android:layout_width="fill_parent"
	    android:layout_height="wrap_content"
	    > 
		<ImageButton  
		    android:layout_width="wrap_content" 
		    android:layout_height="wrap_content" 
		    android:textSize="20sp"
		    android:id="@+id/btnStartPaunse"
		    android:src="@drawable/start"
		    />
		<TextView  
		    android:layout_width="wrap_content" 
		    android:layout_height="wrap_content"
		    android:text="    "
	    	/>
		<ImageButton  
		    android:layout_width="wrap_content" 
		    android:layout_height="wrap_content" 
		    android:textSize="20sp"
		    android:id="@+id/btnStop"
		    android:src="@drawable/stop"
		    />
 	</LinearLayout>

</LinearLayout>

3.strings.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
	<string name="app_name">秒表计时器</string>
    <string name="init_time_second">00:00</string>
    <string name="init_time_100millisecond">00:00:0</string>
    <string name="menu_setting_timer_unit">设置计时单位</string>
    <string name="menu_about">关于</string>
    <string name="menu_exit">退出</string>
    <string name="menu_setting_second">1秒</string>
    <string name="menu_setting_100milisec">0.1秒</string>
</resources>

本程序安装文件下载地址：http://download.csdn.net/source/2606201