android计时器类CountDownTime的运…

1. importandroid.os.Handler;  
2. importandroid.os.Message;  
3.  
4. publicabstractclassAdvancedCountdownTimer {  
5.  
6.    privatefinallongmCountdownInterval;  
7.  
8.    privatelongmTotalTime;  
9.  
10.    privatelongmRemainTime;  
11.  
12.      
13.    publicAdvancedCountdownTimer(longmillisInFuture, longcountDownInterval) {  
14.        mTotalTime = millisInFuture;  
15.        mCountdownInterval = countDownInterval;  
16.  
17.        mRemainTime = millisInFuture;  
18.    }  
19.  
20.    publicfinalvoidseek(intvalue) {  
21.        synchronized(AdvancedCountdownTimer.this) {  
22.            mRemainTime = ((100- value) * mTotalTime) / 100;  
23.        }  
24.    }  
25.  
26.      
27.    publicfinalvoidcancel() {  
28.        mHandler.removeMessages(MSG_RUN);  
29.        mHandler.removeMessages(MSG_PAUSE);  
30.    }  
31.  
32.    publicfinalvoidresume() {  
33.        mHandler.removeMessages(MSG_PAUSE);  
34.        mHandler.sendMessageAtFrontOfQueue(mHandler.obtainMessage(MSG_RUN));  
35.    }  
36.  
37.    publicfinalvoidpause() {  
38.        mHandler.removeMessages(MSG_RUN);  
39.        mHandler.sendMessageAtFrontOfQueue(mHandler.obtainMessage(MSG_PAUSE));  
40.    }  
41.  
42.      
43.    publicsynchronizedfinalAdvancedCountdownTimer start() {  
44.        if(mRemainTime <= 0) {  
45.            onFinish();  
46.            returnthis;  
47.        }  
48.        mHandler.sendMessageDelayed(mHandler.obtainMessage(MSG_RUN),  
49.                mCountdownInterval);  
50.        returnthis;  
51.    }  
52.  
53.    publicabstractvoidonTick(longmillisUntilFinished, intpercent);  
54.  
55.      
56.    publicabstractvoidonFinish();  
57.  
58.    privatestaticfinalintMSG_RUN = 1;  
59.    privatestaticfinalintMSG_PAUSE = 2;  
60.  
61.    privateHandler mHandler = newHandler() {  
62.  
63.        @Override 
64.        publicvoidhandleMessage(Message msg) {  
65.  
66.            synchronized(AdvancedCountdownTimer.this) {  
67.                if(msg.what == MSG_RUN) {  
68.                    mRemainTime = mRemainTime - mCountdownInterval;  
69.  
70.                    if(mRemainTime <= 0) {  
71.                        onFinish();  
72.                    } elseif(mRemainTime < mCountdownInterval) {  
73.                        sendMessageDelayed(obtainMessage(MSG_RUN), mRemainTime);  
74.                    } else{  
75.  
76.                        onTick(mRemainTime, newLong(100 
77.                                * (mTotalTime - mRemainTime) / mTotalTime)  
78.                                .intValue());  
79.  
80.                      
81.                        sendMessageDelayed(obtainMessage(MSG_RUN),  
82.                                mCountdownInterval);  
83.                    }  
84.                } elseif(msg.what == MSG_PAUSE) {  
85.  
86.                }  
87.            }  
88.        }  
89.    };  
90. }

android自带的CountdownTimer源码: 

1.  
2.  
3. packageandroid.os;  
4.  
5. importandroid.util.Log;  
6.  
7.  
8. publicabstractclassCountDownTimer {  
9.  
10.     
11.    privatefinallongmMillisInFuture;  
12.  
13.     
14.    privatefinallongmCountdownInterval;  
15.  
16.    privatelongmStopTimeInFuture;  
17.  
18.     
19.    publicCountDownTimer(longmillisInFuture, longcountDownInterval) {  
20.        mMillisInFuture = millisInFuture;  
21.        mCountdownInterval = countDownInterval;  
22.    }  
23.  
24.     
25.    publicfinalvoidcancel() {  
26.        mHandler.removeMessages(MSG);  
27.    }  
28.  
29.     
30.    publicsynchronizedfinalCountDownTimer start() {  
31.        if(mMillisInFuture <= 0) {  
32.            onFinish();  
33.            returnthis;  
34.        }  
35.        mStopTimeInFuture = SystemClock.elapsedRealtime() + mMillisInFuture;  
36.        mHandler.sendMessage(mHandler.obtainMessage(MSG));  
37.        returnthis;  
38.    }  
39.  
40.  
41.     
42.    publicabstractvoidonTick(longmillisUntilFinished);  
43.  
44.     
45.    publicabstractvoidonFinish();  
46.  
47.  
48.    privatestaticfinalintMSG = 1;  
49.  
50.  
51.    // handles counting down 
52.    privateHandler mHandler = newHandler() {  
53.  
54.        @Override 
55.        publicvoidhandleMessage(Message msg) {  
56.  
57.            synchronized(CountDownTimer.this) {  
58.                finallongmillisLeft = mStopTimeInFuture - SystemClock.elapsedRealtime();  
59.  
60.                if(millisLeft <= 0) {  
61.                    onFinish();  
62.                } elseif(millisLeft < mCountdownInterval) {  
63.                    // no tick, just delay until done 
64.                    sendMessageDelayed(obtainMessage(MSG), millisLeft);  
65.                } else{  
66.                    longlastTickStart = SystemClock.elapsedRealtime();  
67.                    onTick(millisLeft);  
68.  
69.                    // take into account user's onTick taking time to execute 
70.                    longdelay = lastTickStart + mCountdownInterval - SystemClock.elapsedRealtime();  
71.  
72.                    // special case: user's onTick took more than interval to 
73.                    // complete, skip to next interval 
74.                    while(delay < 0) delay += mCountdownInterval;  
75.  
76.                    sendMessageDelayed(obtainMessage(MSG), delay);  
77.                }  
78.            }  
79.        }  
80.    };  
81. }

这个是CountDownTimer的实际运用例子： 

http://gundumw100.iteye.com/admin/blogs/1057989