1. Handler和Thread的關係
Johnny Sung
2013/08/22
多執行緒-
1
Thursday, August 22, 13

2. 關於我
• I'm an Android developer.
Also learning iOS development.
• Information Management
in Shih Hsin University
• 相關作品：
• Good! 愛點兒
• 世新廣播電台
• 主要語⾔言：
• Obj-C / Java / C# / PHP
2
Thursday, August 22, 13

3. Good! 愛點兒
3
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4. 世新廣播電台
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5. 5
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6. 6
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7. 問題
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8. 8
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9. 9
ANR = Activity Not Responding
http://developer.android.com/training/articles/perf-anr.html
Thursday, August 22, 13

10. MultiThreading 多執行緒
•Runnable
•Thread
•Handler
•Message
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11. 11
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12. Runnable
12
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13. 13
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14. class GetWebPicture implements Runnable
{
@Override
public void run()
{
// ........
}
}
14
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15. Thread
顧名思義，它就叫執⾏行緒
15
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16. 16
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17. Thread又有分二種
•單次型 Thread(Java原有的)
•常駐型 HandlerThread (Android特有的)
常駐型 HandlerThread留到後⾯面再說
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18. 18
new Thread(new Runnable()
{
@Override
public void run()
{
// ......
}
}).start();
Thursday, August 22, 13

19. new Thread()
{
@Override
public void run()
{
// ....
}
}.start();
19
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20. Main Thread(UI Thread)20
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21. Main Thread(UI Thread)20
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22. new Thread()
{
@Override
public void run()
{
// ....
}
}.start();
Thread1
Main Thread(UI Thread)20
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23. new Thread()
{
@Override
public void run()
{
// ....
}
}.start();
Thread1
Main Thread(UI Thread)20
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24. new Thread()
{
@Override
public void run()
{
// ....
}
}.start();
Thread1
Main Thread(UI Thread)
runOnUiThread(new Runnable()
{
public void run()
{
// ......
}
});
20
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25. new Thread()
{
@Override
public void run()
{
// ....
}
}.start();
Thread1
Main Thread(UI Thread)
runOnUiThread(new Runnable()
{
public void run()
{
// ......
}
});
20
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26. HandlerThread
是⼀一種常駐型的Thread
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27. mThread = new HandlerThread("name");
mThread.start();
mThreadHandler = new Handler(mThread.getLooper())
{
public void handleMessage(android.os.Message msg)
{
switch (msg.what)
{
case START_SERVER:
// .....
break;
case STOP_SERVER:
// .....
break;
default:
break;
}
}
};
在onCreate()之中
22
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28. 在onDestroy()之中
if (mThread != null)
mThread.quit();
寫在Service裡⾯面不錯⽤用
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29. Main Thread(UI Thread)
onCreate()
onResume()
onPause()
onDestroy()
24
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30. HandlerThread1
Main Thread(UI Thread)
onCreate()
onResume()
onPause()
onDestroy()
mThread = new HandlerThread("name");
mThread.start();
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31. HandlerThread1
Main Thread(UI Thread)
onCreate()
onResume()
onPause()
onDestroy()
mThread = new HandlerThread("name");
mThread.start();
if (mThread != null)
mThread.quit();
24
Thursday, August 22, 13

32. HandlerThread1
Main Thread(UI Thread)
onCreate()
onResume()
onPause()
onDestroy()
mThread = new HandlerThread("name");
mThread.start();
if (mThread != null)
mThread.quit();
(Idle)
(Running)
(Running)
(Idle)
(Idle)
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33. Handler
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34. 26
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35. Handler mHandler = new Handler()
{
@Override
public void handleMessage(Message msg)
{
switch (msg.what)
{
case 0:
// .......
break;
case 1:
// .......
break;
case 2:
// .......
break;
default:
break;
}
}
};
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36. Message
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37. Message就是要一言以蔽之
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38. 用一個值 (一句話)
代表一堆事情(Runnable)
30
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39. 31
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40. obtainMessage(int what);
obtainMessage(int what, int arg1, int arg2);
obtainMessage(int what, int arg1, int arg2, Object obj);
obtainMessage(int what, Object obj);
發訊息
記得加上.sendToTarget()才會發送
sendEmptyMessage(int what)
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41. http://developer.android.com/reference/android/os/Handler.html
其他常用的Method
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42. 我只想寫個小東西
Message & Handler 方式對我來說太複雜了
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43. 有沒有更快的方法？
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44. 有!
36
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45. runOnUiThread()
37
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46. runOnUiThread(new Runnable()
{
public void run()
{
// ......
}
});
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47. 讓我們看一下原始碼
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48. https://github.com/android/platform_frameworks_base/blob/master/core/java/android/app/Activity.java
// Reference from Activity.java
/**
* Runs the specified action on the UI thread. If the current thread is the
* UI thread, then the action is executed immediately. If the current thread
* is not the UI thread, the action is posted to the event queue of the UI
* thread.
*
* @param action
* the action to run on the UI thread
*/
public final void runOnUiThread(Runnable action)
{
if (Thread.currentThread() != mUiThread)
{
mHandler.post(action);
} else
{
action.run();
}
}
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49. 41
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50. Q & A
42
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51. Follow me on Blog
43
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52. Follow me on Facebook
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