The Albert's

60p 與 60i 的差別 (II) 1920x1080/60p vs. 1920x1080/60i

2011-07-31T00:00:00.002+08:00

看得懂下面這張圖的人應該不多! 要瞭解這張圖得先瞭解"逐行掃瞄 (Progressive Scan)"以及"隔行掃瞄 (Interlaced Video)"

逐行掃瞄與隔行掃瞄

逐行掃瞄 (Progressive Scan)如同右圖所示，從第一行到第六行，以由左到右、由上的下的方式在螢幕上做掃瞄；電腦螢幕的掃瞄方式就是這種。Sony Style那張圖右半邊所表達的就是這一類型的掃瞄。該圖的上半部上四幀(Frame)完整的圖所表示的是，以這種格式儲存的每一幀(Frame)都是一張完整的的圖像；如果是以60p的格式來講，它們分別是第1/60秒、2/60秒、3/60秒以及4/60秒的圖像，結合起來就是下半部的視訊(Video)。

Credit: 维基百科

單數行Credit: 维基百科

隔行掃瞄 (Interlaced Video)如左圖邊前兩張圖，它同樣的是由左到右、由上的下的方式在螢幕上做掃瞄；但是跟逐行掃瞄 (Progressive Scan)不同的是，它一幀(Frame)分兩次掃瞄，一次掃瞄奇數行，一次掃瞄偶數行；傳統的電視機螢幕就是這一類型的。

Sony Style那張圖左半邊所表達的就是這種掃瞄。該圖的上半部上四幀(Frame)圖像看起來，中間像是散佈了一些黑線，事實上那是因為它們分別表示奇數或偶數行所構成的圖像；如果是以60i的格式來講，它們同樣是第1/60秒、2/60秒、3/60秒以及4/60秒的圖像，結合起來就是下半部的視訊(Video)。

因為奇數行的掃瞄時間與偶數行的掃瞄時間差了1/60秒，所以如果把相臨的兩幀結合在一起，不會是一張正常的圖像，而是類似左邊第三張圖像的狀況。

偶數行Credit: 维基百科

奇數行 + 偶數行Credit: Wikipedia

(待續...)

參考網頁:
AVCHD (From Wikipedia, the free encyclopedia)
AVCHD (维基百科)
H.264/MPEG-4 AVC (From Wikipedia, the free encyclopedia)
AVCHD (维基百科)
Progressive Scan(From Wikipedia, the free encyclopedia)
逐行掃瞄 (维基百科)
Interlaced Video(From Wikipedia, the free encyclopedia)
隔行掃瞄 (维基百科)
Sony Style(Taiwan)/Cyber-shot 數位相機 DSC-HX9V/B

60p 與 60i 的差別 (I) 1920x1080/60p vs. 1920x1080/60i

2011-07-28T22:51:00.001+08:00

在數位相機以及數位攝影機的攝影檔案格式裡會常常看到類似 1920x1080/60p 以及 1920x1080/60i的規格。這兩種規格是應用在高解析度視訊(High-Definition Video)上的檔案規格，而且都是屬於所謂的 AVCHD (Advanced Video Coding High Definition) 的檔案格式。AVCHD 的基礎是 H.264/MPEG-4 (AVC)視訊編碼標準，被應用在標準、高解析度以及3D視訊。

在60p裡的"p"表示的是逐行掃瞄 (Progressive Scan)。下面是 Sony Style 網頁上的模擬照片；右邊的照片模擬的就是60p...

Credit: Sony Style(Taiwan)

至於60i裡的"i"表示隔行掃瞄 (Interlaced Video)；左邊的照片模擬的就是60i。

60p 與 60i 的差別 (II) -- 逐行掃瞄與隔行掃瞄

參考網頁:
AVCHD (From Wikipedia, the free encyclopedia)
AVCHD (维基百科)
H.264/MPEG-4 AVC (From Wikipedia, the free encyclopedia)
AVCHD (维基百科)
Progressive Scan(From Wikipedia, the free encyclopedia)
逐行掃瞄 (维基百科)
Interlaced Video(From Wikipedia, the free encyclopedia)
隔行掃瞄 (维基百科)

LUMIX 數位相機所標示的iA是什麼意思?

2011-07-16T21:27:00.004+08:00

在LUMIX的規格表裡所出現的iA，就是Panasonic所謂的Intelligent Auto Technology (智慧自動技術)，它包括了下列六種功能；它們的圖示會標示在含有該功能相機上:

Mega O.I.S (Optical Image Stabilization;自動光學防手震):
這個功能可以偵測到相像細微的移動，自動調節鏡頭以補償所偵測到的移動。

Intelligent ISO (動態自動感光):
這個功能可以感測目標物體的移動，自動提高ISO以及快門，使得拍攝快速移動的動體變得更簡單。

Face Detection(人臉偵測):
這個功能可以自動捕捉臉部以及為所補捉到的臉部取得最佳的設定;它最高可以捕捉到15個臉部。

Scene Detection (自動場景選擇):
自動偵測並設定拍攝的背景。

AF Tracking (動能追踪對焦):
在按下拍攝按鍵或在LCD螢幕上觸碰拍攝目標後，相機會自動幫忙追踪移動的目標。

Intelligent Exposure (智慧曝光):
智慧曝光的功能會自動修正曝光的程度，讓相片的呈現更為自然。

參考網頁:
DMC-GF2K
iA - INTELLIGENT AUTO TECHNOLOGY
Intelligent Auto Mode: the easy way to get great shots every time

Closer to the Edgeby 30 Seconds to Mars

2011-07-11T22:23:00.000+08:00

"Closer to the Edge" 這首歌是美國搖滾團體30 Seconds to Mars 在他們2009年在發行的專輯 This is War 裡的第七首歌曲。這個來自洛杉磯的樂團成立於1998年，Jared Leto 是這個樂團的主唱...

I don't remember one moment, I tried to forget
I lost myself, is it better not said
Now I'm closer to the edge

It was a thousand to one
And a million to two
Time to go down in flames and I'm taking you
Closer to the edge

No, I'm not saying I'm sorry
One day maybe we'll meet again
No, I'm not saying I'm sorry
One day maybe we'll meet again
NO NO NO NO

Can can can you imagine a time when the truth ran free
The birth of a song and the death of a dream (The birth of a sun the death of a dream)
Closer to the edge

This never ending story
Paid for with pride and fate
We all fall short of glory
LOST IN OUR FATE

No, I'm not saying I'm sorry
One day maybe we'll meet again
No, I'm not saying I'm sorry
One day maybe we'll meet again
NO NO NO NO

NO NO NO NO

I will never forget
NO NO
I will never regret
NO NO
I WILL LIVE MY LIFE
NO NO NO NO
I will never forget
NO NO
I will never regret
NO NO
I WILL LIVE MY LIFE

No, I'm not saying I'm sorry
One day maybe we'll meet again
NO NO
No, I'm not saying I'm sorry
One day maybe we'll meet again
NO NO NO NO

Closer to the edge
Closer to the edge
NO NO NO NO

Closer to the edge
Closer to the edge
NO NO NO NO

Closer to the edge

Lumix vs. NEX 規格的比較

2011-07-10T18:11:00.004+08:00

Panasonic的LUMIX GF系列以及Sony的NEX系列這兩款數位相機都號都號稱是最小的數位單眼相機，是目前市面上數位單眼相機最夯的入門機種，已經有很多介紹它們的書籍出現，網路上也有不少的討論；但是，這兩者在規格上到底有什麼差異?

這兩款相機在最基本的感光元件雖然都標示著APS-C (Advanced Photo System Type-C)，但實質上它們的尺寸是不一樣的。NEX系列採用的是23.4 X 15.6 mm的感光元件，比較接近APS-C的尺寸；而LUMIX是使用17.3 X 13 mm的所謂Micro 4/3 (Micro Four Thirds)的感光元件，因為比正常的APS-C小，所以稱之為Micro；從以上感光元件的尺寸，可以看得出來它們的長寬比是不一樣的，NEX的長寬比為3:2，而LUMIX為4:3。

因為這個感光元件上的差異，畫素當然也就跟著會有差別；就NEX來說，總畫素/有效畫素是1460M/1420M，而LUMIX的則是1306M/1210M。由此推論，如果要比較這兩款相機的執行效率，尤其在連續/快速拍照時，對NEX可能會有點不利；因為它們畫素雖然只差了200M，但是從畫素的差別直接影響的資料的處理量；也就是說，兩款相機都設定在最高品質的狀況下操作，NEX需在比LUMIX更快的速度處理影像資料。

下面的是LUMIX GF3與NEX-5部份值得參考規格的比較:

	NEX-5	LUMIX GF3
鏡頭接環	E-mount	Micro Four Thirds Mount
鏡頭換算比	1.5	2.0
感光元件	23.4x15.6mm	17.3x13mm
	3:2	4:3
	1460M/1420M	1306M/1210M
影像格式		[4:3]L 尺寸：4,000 x 3,000、M 尺寸：2,816 x 2,112、S 尺寸：2,048 x 1,536、3D 尺寸：1,600 x 1,200
	[3:2]L 尺寸：4592 x 3056（14M）、M 尺寸：3344 x 2224（7.4M）、S 尺寸：2288 x 1520（3.5M）	[3:2]L尺寸：4,000 x 2,672 、 M尺寸：2,816 x 1,880 、S尺寸： 2,048 x 1,360、3D尺寸：1,600 x 1,064
	[16:9]L 尺寸：4592 x 2576（12M）、M 尺寸：3344 x 1872（6.3M）、S 尺寸：2288 x 1280（2.9M）	[16:9]L尺寸：4,000 x 2,248 、M尺寸： 2,816 x 1,584、S尺寸：1,920 x 1,080、3D尺寸：1,600 x 904
		[1:1]L尺寸：2,992 x 2,992 、 M尺寸：2,112 x 2,112 、 S尺寸：1,504 x 1,504 、 3D尺寸：1,440 x 1,440
錄影影像格式	AVCHD: 1920 x 1080 (59.94i - 17Mpbs)
	[HD] 1440 x 1080 (29.97 fps – 12 Mbps)	[HD] 1,280 x 720, 30 fps
	VGA: 640 x 480 (29.97 fps – 3 Mbps)	VGA: 640 x 480, 30 fps
		QVGA: 320 x 240, 30 fps
ISO感光度範圍	ISO 200~128,000	ISO 160~64,000
LCD顯示器	7.5公分(3.0吋)，TFT 921,600 點	7.5公分(3.0吋)，TFT 460,000 點
重量	約287公克（10.1 盎司）（含電池與 Memory Stick PRO Duo 記憶卡）	約264公克（9.31 盎司） (含SD card, 電池, 機身)
重量	約 229 公克（8.1 盎司）（僅機身）	約 222 公克（7.83 盎司）（僅機身）
尺寸	約 110.8 x 58.8 x 38.2mm（4-5/8 x 2-3/8 x1-9/16 吋）（不含突出物）	約107.7 x 67.1 x 32.5mm（4.24 x 2.64 x 1.28吋）（不含突出物）
閃光燈	外接閃光燈指數:7（以相當於 ISO 100 時拍攝所測量的公尺）	內建閃光燈指數: 6.3 (以相當於 ISO 160 時拍攝所測量的公尺)

Sony NEX系列DSLR (NEX-3、NEX-5) 有什麼不同?

2011-07-09T20:54:00.001+08:00

Sony數位單眼相機NEX系列(NEX-3、NEX-5)從它們的規格表上看起來，除了在重量以及尺寸上有些微的差異以外，他們主要的不同是錄影格式的部份；以下是有差異部份的對照表:

項目	NEX-3	NEX-5
錄影格式	MP4 影像壓縮格式 : MPEG-4 影像聲音錄製格式 : MPEG-4 AAC-LC	AVCHD，MP4 影像壓縮格式 : MPEG-4 AVC (H.264) 聲音錄製格式 : 數位杜比音效 (AC-3 ) / MPEG-4 AAC-LC
影像尺寸(像素)	MP4: 1280 x 720 (29.97 fps – 9/6 Mbps) VGA: 640 x 480 (29.97 fps – 3 Mbps)	[1080 60i- 相容 / NTSC] AVCHD: 1920 x 1080 (59.94i - 17Mpbs) MP4: 1440 x 1080 (29.97 fps – 12 Mbps) VGA: 640 x 480 (29.97 fps – 3 Mbps)
影像尺寸(像素)	MP4: 1280 x 720 (25 fps – 9/6 Mbps) VGA: 640 x 480 (25 fps – 3 Mbps)
過片模式	單張、連續、高速連拍、自拍（可選擇 10 秒或 2 秒延遲）、連續自拍（可選擇 10 秒延遲，3/5 曝光選擇)	單張、連續、高速連拍、自拍（可選擇 10 秒或 2 秒延遲）、連續自拍（可選擇 10 秒延遲，3/5 曝光選擇）、遙控器 (選購)
重量	約 297 公克（10.5 盎司）（含電池與Memory Stick PRO Duo記憶卡）約 239 公克（8.4 盎司）（僅機身）	約 287 公克（10.1 盎司）（含電池與 Memory Stick PRO Duo 記憶卡）約 229 公克（8.1 盎司）（僅機身）
尺寸	約 117.2 x 62.6 x 33.4mm（4-5/8 x 2-1/2 x1-3/8 吋）（不含突出物）	約 110.8 x 58.8 x 38.2mm（4-5/8 x 2-3/8 x1-9/16 吋）（不含突出物）

Sony 平板電腦(Tablet)欣賞

2011-07-08T22:23:00.009+08:00

Sony發表的平板電腦S1以及S2

Sony平板電腦 Two Will -- 序

Sony平板電腦 Two Will -- 第一幕

Sony平板電腦 Two Will -- 第二幕

Sony平板電腦 Two Will -- 第三幕

Sony平板電腦 Two Will -- 第四幕

第五幕即將於八月廿三號推出敬請期待...

資料來源網站：http://www.sony.jp/tablet/

Facebook 以及 Google+ 你準備選邊了嗎?

2011-07-06T21:53:00.016+08:00

最近谷歌宣佈Google+計劃進入測試階段，絶大部份應邀請參與這項測試的先進以及網友們在試用了之後，也都迫不及待的極力推薦谷歌的這項產品，把社交網路(Social Network)炒得沸沸揚揚的，同時也造成網路上不小的騷動。似乎為數不少的網友已經開始引領期盼Google+的正式上線！您呢?

(Credit: Josh Lowensohn/CNET)

從這兩天的新聞可以嗅到Facebook以及Google兩大陣營互相較勁的味道了！根據CNet的報導，Facebook已經準備在他們的總部發佈有關新服務的簡報，這些新服務包括平板電腦應用程式、照片分享、音樂欣賞(可能跟Spotify有關)，甚至提到以Skype為基礎的視訊服務(Video Chat Service)等等。
這一連串的變化，都是肇始於谷歌發佈的Google+計劃！這個計劃給整個社交網路帶來了進步的契機，沒有谷歌的這個刺激，Facebook不會有如此快速的轉變！顯而易見的，這個社交網路這塊大餅提供這兩大陣營多麼大的動力！
在這之前，雖然有零星的相關產品出現，但是對Facebook都沒構成什麼威脅。但這一次就不同了，Google+計劃的出現，把原來一家”獨佔”的局面打破了；這整個事件對使用者來說應該算是一項利多，必竟經過這兩年，Facebook並不是那麼的長進；但是從另外一個角度看來，龜步的Facebook也並非一無是處，經過了這兩年的淬鍊，已經可以說是相對的穩定了；或許，在冒然投入Google+的懷抱之前，先瞭解一下Google+的優點、強項再”下手"不遲！

Google+ 計劃

2011-07-03T13:54:00.010+08:00

Google的Google+計劃現在已經到了測試(Field Trial)的階段了。既然已經進行測試，它的使用說明也已經上線；因此，現在雖然我們沒辦法試用、一窺究竟，也只能到它的官網瞭解一下。

從Google+的說明，可以看到它包含了下面幾個重要的元件，這些組成元件可以在Google+計劃的官網上看到詳細的說明。在英文版的官網則可以看到它的Demo畫面。

社交圈(Circles)
話題靈感(Sparks)
視訊聚會(Hangouts)
即時上傳 (Instant Upload)
閒聊(Huddle)

Google似乎把目前使用在網路以及行動裝置上的互動工具做了一個整合，其中包含了即時通、視訊以及社交網站等等。在乍看之下，它們幾乎可以對應到Facebook的功能；但是它給人的第一個印象是它使用了一個非常不錯的概念--圈圈(Circles)。圈圈(Ciucles)的概念，說穿了就是集合的概念，或者是說是一種分類！它可以說非常的接近我們一般的日常生活。在學校上課有同學、老師，是一個或多個圈圈；在工作場所有同事、客戶又是另外一個或多個圈圈；下了班、放了學又有各自的朋友、親人等等好幾個圈圈...，這些圈圈有可能有交集、聯集，或一點關係也沒有。在Facebook上，要分類也不是一個大問題，"建立名單"之後，把朋友放進去也就解決了，但是因為它並沒有內建的相關功能，所以感覺上不是那麼的好用。再者，Google應該會不會把它們的產品晾在一邊！Google勢必會把它們現有的工具或服務（例如，網路搜尋、Gmail、Gtalk、Google定位、Picasa以及快訊等等）整合到Google+裡。相信Google+計劃是蠻值得期待的！

探索Java的初步

2009-05-06T23:09:00.006+08:00

在嚐試分別用VB、VC#以及VC++寫出完全相同的讀取Email標頭檔的程式之後，腦袋突然出現了一個念頭:"用Java怎麼寫這個程式?"。事實上, Java出現的時間也不算短，但是亞伯特還真的從來沒有用過Java! 記得過去曾經有機會不經意的瀏覽Java的程式, 總覺得看來十分眼熟, 跟C++相當類似, 所以也就不是很在意; 因此, 這次心想這個應該是不會太難的吧! 經過幾天的摸索, 才發現Java跟C++還是有相當的差異! 無論如何, 還是得從根本瞭解Java才是。以下是亞伯特這幾天"扒"出來的一些東西, 給對Java有興趣的大大們參考, 同時也可以節省在這個部份摸索的時間與精神。當然, 也希望有經驗的前輩們能夠出面指點一二, 亞伯特感激不盡! 取得工具軟體
要使用Java免不了要有可以編輯以及組譯(Compile)的工具程式, 而由昇陽電腦（Sun Microsystems)所提供的NetBeans看來應該是目前不二的選擇吧! 看看維基百科對它的介紹, 多少多少對認識這個玩意兒有點幫助。NetBeans (完整名稱應該是NetBeans IDE吧) 目前的正式版本是6.5.1, 另外有一個Beta(測試)版6.7, 這兩個版本都有所謂的 "正體中文版", 以上的連結就是它們的下載網頁; 亞伯特原來下載的是英文版, 並沒有注意到正體中文版, 一直到發現它無法顯示中文時, 才試著去找到中文版! 另外, 亞伯特發現NetBeans的6.5.1版跟6.7版居然可以同時並存在同一台電腦上! 初步使用 NetBeans並不是很順手, 總覺得Visual Studio似乎比較習慣, 看來可能要花一點時間適應了!
Java的基礎 昇陽 (Sun Microsystems) 不但提供Java的教學網頁 "The Java Tutorials", 而且這些教學的網頁是可以下載的。這裡的內容看來蠻多的, 不過它是英文版的, 如果要看中文版的話可得找找看了, 或許有簡體中文版吧! 我想應該可以從這裡開始瞭解Java這個玩意是不會錯的!
其它的參考文件 在Java SE APIs & Documentation 提供一些看來比較進階的說明文件。這裡就可以看到標有 "Chinese" 的中文版的東西, 它是可是只有 "簡體中文版" 的文件哦!
昇陽開發者網路
昇陽的Sun Developer Network (SDN) 網站裡應該提供不少的有用的連結以及資訊, 有時間再去逛逛吧! 目前亞伯特也還是一知半瞭的, 無法提供更多的資訊囉! :0<

2009-05-02T19:14:00.003+08:00

在POP3的基本作業(Basic Operation)提到了幾個基本的操作；而事實上這幾個操作都包含在POP3 == RFC 1939一文中所提到的POP3Client類別(Class)裡。這個類別原來是用C#(C Sharp)寫的，最近亞伯特把它整理了一下，同時也改寫成VB以及VC++以供參考。連接POP3伺服器函數(Function) Connect() 這個函數使用型別為TcpClient的物件(tcClient)來連接POP3伺服器；在連接的同時，這個函數會建立一個型別為NetwrokStream的物件(nsStream)，這個物件用夾提供網路存取資料的功能；呼叫它時，必須提供伺服器稱(例如HiNet的郵件伺服器，ms1.hinet.net)以及埠號(按照POP3，通常是110)。函數在結束時呼叫函數GetResponse()，這個函數負責透過nsStream讀取伺服器回應的訊息，並且判斷連結是否成功： [VB 的程式碼] Public Function Connect(ByVal Server As String, ByVal Port As Integer) As Boolean '--- 連接伺服器/Connect to POP3 server ------------------------------ Try tcClient = New TcpClient(Server, Port) nsStream = tcClient.GetStream() nsStream.ReadTimeout = 15000 Catch Throw End Try Return GetResponse() End Function [VC#的程式碼] public bool Connect(string Server, int Port) { //--- 連接伺服器/Connect to POP3 server ------------------------------ try { tcPOP3Client = new TcpClient(Server, Port); nsStream = tcPOP3Client.GetStream(); nsStream.ReadTimeout = 15000; } catch (SocketException) { throw; } return GetResponse(); } [VC++的程式碼] bool CPOP3Client::Connect(String^ Server, int Port) { //--- 連接伺服器/Connect to POP3 server ------------------------------ try { tcPOP3Client = gcnew TcpClient(Server, Port); nsStream = tcPOP3Client->GetStream(); nsStream->ReadTimeout = 15000; } catch (...) { throw; } return GetResponse(); } 登錄POP3伺服器函數Logon() 它藉著呼叫函數Request()執行登錄的動作；Request函數是透過nsStream把要求傳給伺服器，然後呼叫GetResponse()函數取得回應的訊息，並且藉由該訊息判斷是否登錄成功： [VB 的程式碼] Public Function Logon(ByVal Username As String, ByVal Password As String) As Boolean '--- 登錄郵件伺服器/Logon POP3 server -------------------------------- ' Return Request("USER", Username) And Request("PASS", Password) End Function [VC#的程式碼] public bool Logon(string UserName, string Password) { //--- 登錄郵件伺服器/Logon POP3 server -------------------------------- return Request("USER", UserName) && Request("PASS", Password); } [VC++的程式碼] bool CPOP3Client::Logon(String^ UserName, String^ Password) { //--- 登錄郵件伺服器/Logon POP3 server -------------------------------- return Request("USER", UserName) && Request("PASS", Password); } [VB 的程式碼] Private Function Request(ByVal Command As String) '--- 傳送指令給伺服器/Request POP3Server ----------------------------- Dim bytCommand() As Byte = Encoding.ASCII.GetBytes(Command & vbCrLf) nsStream.Write(bytCommand, 0, bytCommand.Length) Return GetResponse() End Function [VC#的程式碼] private bool Request(string Command) { //--- 傳送指令給伺服器/Request POP3Server ----------------------------- Byte[] bytCommand; bytCommand = Encoding.ASCII.GetBytes(Command + "\r\n"); nsStream.Write(bytCommand, 0, bytCommand.Length); return GetResponse(); } [VC++的程式碼] bool CPOP3Client::Request(String^ Command) { //--- 傳送指令給伺服器/Request POP3Server ----------------------------- array<Byte>^ bytCommand; bytCommand =Encoding::ASCII->GetBytes(Command + "\r\n"); nsStream->Write(bytCommand, 0, bytCommand->Length); return GetResponse(); } 讀取伺服器回應訊息的函數GetResponse() 如前所述，GetResponse()是透過nsStream讀取伺服器的回應訊息；所以GetResponse()不但要正確的取得伺服器的回應，而且要判斷該訊息是成功(+OK)的訊息或者是失敗(-ERR)的訊息。 [VB 的程式碼] Public Function GetResponse() As Boolean '--- 讀取伺服器回應的資料/Get response from POP3 server --------------- Dim iBytes As Integer Dim bOk As Boolean Try '--- 讀取資料/Getting Data -------------------------------------- iBytes = nsStream.Read(bytData, 0, bytData.Length) strResponse = Encoding.ASCII.GetString(bytData, 0, iBytes) bOk = strResponse.StartsWith("+OK") '--- 多行的處理/For multi-line ----------------------------------- If (strResponse.IndexOf(vbCrLf) < (iBytes - 2)) Then Do While Not (strResponse.EndsWith("." & vbCrLf)) iBytes = nsStream.Read(bytData, 0, bytData.Length) strResponse &= Encoding.ASCII.GetString(bytData, 0, iBytes) Loop strResponse = strResponse.Substring(0, strResponse.Length - 3) strResponse = Unfolding(strResponse) End If If bOk Then strResponse = strResponse.Substring(3) _ Else strResponse.Substring(4) strResponse = strResponse.TrimStart() Catch bOk = False End Try Return bOk End Function [VC#的程式碼] private bool GetResponse() { //--- 讀取伺服器回應的資料/Get response from POP3 server --------------- int iBytes; bool bOK = false; try { //--- 讀取資料/Getting Data -------------------------------------- iBytes = nsStream.Read(bytData, 0, bytData.Length); strResponse = Encoding.ASCII.GetString(bytData, 0, iBytes); bOK = strResponse.StartsWith("+OK"); //--- 多行的處理/For multi-line ----------------------------------- if ((strResponse.IndexOf("\r\n") < (iBytes - 2))) { while (!strResponse.EndsWith(".\r\n")) { iBytes = nsStream.Read(bytData, 0, bytData.Length); strResponse += Encoding.ASCII.GetString(bytData, 0, iBytes); } strResponse = strResponse.Substring(0, strResponse.Length - 3); strResponse = Unfolding(strResponse); } if (bOK) strResponse = strResponse.Substring(3); else strResponse.Substring(4); strResponse = strResponse.TrimStart(); } catch (IOException) { bOK = false; } return bOK; } [VC++的程式碼] bool CPOP3Client::GetResponse() { //--- 讀取伺服器回應的資料/Get response from POP3 server --------------- int iBytes; bool bOK = false; try { //--- 讀取資料/Getting Data -------------------------------------- iBytes = nsStream->Read(bytData, 0, bytData->Length); strResponse = Encoding::ASCII->GetString(bytData, 0, iBytes); bOK = strResponse->StartsWith("+OK"); //--- 多行的處理/For multi-line ----------------------------------- if ((strResponse->IndexOf("\r\n") < (iBytes - 2))) { while (!strResponse->EndsWith(".\r\n")) { iBytes = nsStream->Read(bytData, 0, bytData->Length); strResponse += Encoding::ASCII->GetString(bytData, 0, iBytes); } strResponse = strResponse->Substring(0, strResponse->Length - 3); strResponse = Unfolding(strResponse); } strResponse=bOK?strResponse->Substring(3):strResponse->Substring(4); strResponse=strResponse->TrimStart(); } catch (...) { bOK = false; } return bOK; } 　

POP3 的三章--基本作業 (Basic Operation)

2009-04-20T23:37:00.003+08:00

在先前的POP3 == RFC 1939文中提到 "...只要看RFC 1939的第三頁到第五頁，就大致上把它主要規則的描述看完了..."，但是在該文中，並沒有提及該部份詳細的內容！以下是針對該部分所做的補充，把POP3的第三章基本操作 (Basic Operation) 介紹一下。（英文斜體的部分是POP3的原文，中文的部分僅供參考） Initially, the server host starts the POP3 service by listening on TCP port 110. When a client host wishes to make use of the service, it establishes a TCP connection with the server host. When the connection is established, the POP3 server sends a greeting. The client and POP3 server then exchange commands and response (respectively) until the connection is closed or aborted. POP3伺服器會監聽TCP的埠號第110 (這也就是POP3的預設通訊埠)。當用戶端的電腦想要使用POP3的服務時，它會透過TCP與伺服器連線。連線成功之後，伺服器會向用戶端電腦送出問候語，表示伺服器已經可以正確的提供服務。接下來，伺服器與用戶端就可進行直接的交談。 Commands in the POP3 consist of a case-insensitive keyword, possibly followed by one or more arguments. All commands are terminated by a CRLF pair. Keywords and arguments consist of printable ASCII characters. Keywords and arguments are each separated by a single SPACE character. Keywords are three or four characters long. Each argument may be up to 40 characters long. POP3所使用的命令並沒有大小寫之分，而且有可能會有一個以上的參數；所有的命令都是以CRLF (Carriage Return + Line Feed) 結束的。這些使用三到四個字元的命令關鍵字以及它的參數之間是以空格分開，同時都是可列印的ASCII字碼；至於參數可以長逹40個英文字元。 Responses in the POP3 consist of a status indicator and a keyword possibly followed by additional information. All responses are terminated by a CRLF pair. Responses may be up to 512 characters long, including the terminating CRLF. There are currently two status indicators: positive ("+OK") and negative ("-ERR"). Servers MUST send the "+OK" and "-ERR" in upper case. POP3伺服器的回應除了包含一個狀態的指示及一個關鍵字之外，可能再加上其它的資訊；整個回應的長度可以長達512個字元；同樣的，所有的回應都是以CRFL結束。目前所使用的狀況指示有以下兩個：表示正常的 "+OK" 以及表示失敗的 "-ERR"；它們都必須以大寫表示。 Responses to certain commands are multi-line. In these cases, which are clearly indicated below, after sending the first line of the response and a CRLF, any additional lines are sent, each terminated by a CRLF pair. When all lines of the response have been sent, a final line is sent, consisting of a termination octet (decimal code 046, ".") and a CRLF pair. If any line of the multi-line response begins with the termination octet, the line is "byte-stuffed" by pre-pending the termination octet to that line of the response. Hence a multi-line response is terminated with the five octets "CRLF.CRLF". When examining a multi-line response, the client checks to see if the line begins with the termination octet. If so and if octets other than CRLF follow, the first octet of the line (the termination octet) is stripped away. If so and if CRLF immediately follows the termination character, then the response from the POP server is ended and the line containing ".CRLF" is not considered part of the multi-line response. 如果伺服器的回應包含多行的話，除了最後一行是以 ".CRLF" 當結尾以外，其它每一行都是以 "CRLF" 為結尾的。此外，在多行回應的狀況下，如果是以"."為開頭，其後接的是CRLF，則它被視為是最末行；如果其後接的是CRLF以外的字元，則"."這個符號是可以被忽略的。 A POP3 session progresses through a number of states during its lifetime. Once the TCP connection has been opened and the POP3 server has sent the greeting, the session enters the AUTHORIZATION state. In this state, the client must identify itself to the POP3 server. Once the client has successfully done this, the server acquires resources associated with the client's maildrop, and the session enters the TRANSACTION state. In this state, the client requests actions on the part of the POP3 server. When the client has issued the QUIT command, the session enters the UPDATE state. In this state, the POP3 server releases any resources acquired during the TRANSACTION state and says goodbye. The TCP connection is then closed. 一但用戶端電腦與伺服器建立連線，而且伺服器對用戶端電腦送出問候語之後，就進入了驗證階段。在這個階段，用戶端電腦必須表明使用者的身份。驗證成功之後，則可以進入傳輸階段；在這個階段，用戶端電腦可以對伺服器要求所需要的資訊。最後，當用戶端送出QUIT命令之後，進入更新階段；這時伺服器向用戶端道別，並結束連線。 A server MUST respond to an unrecognized, unimplemented, or syntactically invalid command by responding with a negative status indicator. A server MUST respond to a command issued when the session is in an incorrect state by responding with a negative status indicator. There is no general method for a client to distinguish between a server which does not implement an optional command and a server which is unwilling or unable to process the command. 這段的意思大概就是說，伺服器對於它沒有辦法處理的命令一概回應"-ERR"；用戶端基本上沒有辦法由它的回應判斷錯誤的原因。 A POP3 server MAY have an inactivity autologout timer. Such a timer MUST be of at least 10 minutes' duration. The receipt of any command from the client during that interval should suffice to reset the autologout timer. When the timer expires, the session does NOT enter the UPDATE state--the server should close the TCP connection without removing any messages or sending any response to the client. POP3伺服器可以有一個計時器，這個計時器的設定值至少為十分鐘。在接收到用戶端的任何要求的同時，將會把這個計時器復歸；如果在這個計時器的計時結束時，尚未進入更新階段，則伺服器應自動中斷連線；在中斷連線時不會移除任何訊息，也不會給用戶端任何回應。

Delegate and Thread-Safe

2009-02-12T00:29:00.006+08:00

中文版按這裡

In two previous articles, "POP3 == RFC 1939" and "What the hell is "=?big5?B? "?" (They were written in Chinese and I'll translate those into English afterward.), which discuss about reading messages from a POP3 server and decoding Chinese characters from header of messages. It is a problem to interrupting the message reading for the program mentioned above, due to single thread execution. It means only one thread is used for executing the program; And it is not able to monitor requests from user, such as a "Cancel" button has been clicked by user, while this single thread is busy for getting messages from POP3 server. To quit the program seems the only way to interrupt message reading during a long waiting time cause by a large amount of messages on server. However, we can let the program check requests from user after pausing message reading, and then does the exact same things in next loops till the end/stop of reading. It'll cost a longer reading period of time and make the program more complicated. Multithreading is another alternative solution and it is an easier one for programming, frankly. For example, use the original tread to monitor requests form user and an additional one for messages reading. Multithreading might help us out of this; nevertheless, it causes new problems! That is, threads compete against each others for resources; it makes executions unpredictable! We don't want to see these happening. Let's read related information on MSDN: "Access to Windows Forms controls is not inherently thread safe. If you have two or more threads manipulating the state of a control, it is possible to force the control into an inconsistent state. Other thread-related bugs are possible, such as race conditions and deadlocks. It is important to make sure that access to your controls is performed in a thread-safe way." It has to be tested which thread the control belongs to before manipulating it, in order to keep away from those situations of race conditions and deadlocks. A thread is allowed to manipulate a control, if it was created by this thread. Otherwise, this thread has to "ask" help from the one that created that control; This is so-called "Thread-Safe". You might want to know what on earth the "Thread-Safe" is, please refers to the article "Thread-Safe的理解與分析" of "蕭沖的書房", you might be able to get a rough idea about it! There is copious example on MSDN for explanation about thread-safe, following are excerpt from the example. It's main concept is that checking the value of property InvokeRequired to decide whether the caller must call an Invoke method when making method calls to the control because the caller is on a different thread than the one the control was created on. This means that InvokeRequired can return false if Invoke is not required (the call occurs on the same thread). And "Delegate" is a helpful tool in the case of Invoke is required. Check it out following: namespace CrossThreadDemo { public class Form1 : Form { // This delegate enables asynchronous calls for setting // the text property on a TextBox control. // (And it will be applied for making the method "Invoke" call.) delegate void SetTextCallback(string text); ... Following is the major part of thread-safe for setting a property of control. // This method demonstrates a pattern for making thread-safe // calls on a Windows Forms control. // // If the calling thread is different from the thread that // created the TextBox control, this method creates a // SetTextCallback and calls itself asynchronously using the // Invoke method. // // If the calling thread is the same as the thread that created // the TextBox control, the Text property is set directly. private void SetText(string text) { // InvokeRequired required compares the thread ID of the // calling thread to the thread ID of the creating thread. // If these threads are different, it returns true. // (the Delegate "SetTextCallback" can be find here.) if (this.textBox1.InvokeRequired) { SetTextCallback d = new SetTextCallback(SetText); this.Invoke(d, new object[] { text }); } else { this.textBox1.Text = text; } }

The Delegate of C#

2009-02-08T17:34:00.000+08:00

中文版

What the hell is Delegate? Let's read about it on MSDN: "A delegate is a type that defines a method signature, and can be associated with any method with a compatible signature. You can invoke (or call) the method through the delegate. Delegates are used to pass methods as arguments to other methods. Event handlers are nothing more than methods that are invoked through delegates." Hum~, it's a little bit hard to get it straight! Let's take another shot on MSDN: "A delegate is a reference type that can be used to encapsulate a named or an anonymous method. Delegates are similar to function pointers in C++; however, delegates are type-safe and secure." All right, forget about the definition of it, let's try the example codes provided on MSDN. We might get a rough idea of it: // Declare delegate -- defines required signature: // Any methods that instantiated with it has to match it's signature: // A parameter of double is required and returns a double. delegate double MathAction(double num); class DelegateTest { // Regular method that matches signature: static double Double(double input) { return input * 2; } static void Main() { // Instantiate delegate with named method: // "ma" in the next line is "similar to function pointers in C++" , expressed previously. MathAction ma = Double; // Invoke delegate ma: // The express "ma(4.5)" is identical to "Double(4.5)" double multByTwo = ma(4.5); Console.WriteLine(multByTwo); // Instantiate delegate with anonymous method: // The concept of anonymous method is similar to the previous one. MathAction ma2 = delegate(double input) { return input * input; }; double square = ma2(5); Console.WriteLine(square); // Instantiate delegate with lambda expression MathAction ma3 = s => s * s * s; double cube = ma3(4.375); Console.WriteLine(cube); } } The example code above is executable directly! All you need is creating a Console Application of C#, and then paste the example to the file Program.cs; Be aware of the first line "using System;" that was generated automatically while new project was creating. It is necessary for running the example correctly.

The Basic of ASP.NET Pages -- Understand The Events

2008-10-29T21:33:00.000+08:00

中文版(點選這裡)

Understanding the occurrence of events is helpful for programming. It is a truth for programming ASP.NET pages as well.
"It is important for you to understand the page life cycle so that you can write code at the appropriate life-cycle stage for the effect you intend."
It is quoted from a web page of Microsoft which emphasizes the importance of trigged events in the life cycle of ASP.NET pages. This "ASP.NET Page Life Cycle Overview" gives you a overall concept of events in the life cycle of ASP.NET pages.
Following is quoted form the same web page. I think it might be important for beginners of ASP.NET, just like Albert.
"Pages also support automatic event wire-up, meaning that ASP.NET looks for methods with particular names and automatically runs those methods when certain events are raised. If the AutoEventWireup attribute of the @ Page directive is set to true (or if it is not defined, since by default it is true), page events are automatically bound to methods that use the naming convention of Page_event, such as Page_Load and Page_Init."
The first line of the code of the default ASP.NET page "Default.aspx" which is created automatically after starting a brand-new ASP.NET Web Site is beneath,

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>

This line, starts with @Page, has the option parameter "AutoEventWireup" and it's default value is "true". As matter of fact, the value of AutoEventWireup is set to true, it's default value, if it is omitted on purpose. The execution of codes for these event handlers depend on this option (AutoEventWireup.) And furthermore, the names of these event handlers are prefixed with "Page_", such as Page_Load, Page_Init.

About the Official Microsoft ASP.NET Site

2008-10-26T22:19:00.000+08:00

中文版(點選這裡)

The webpage of ASP.Net of Microsoft Taiwan is part of MSDN (Microsoft Developer Network.) It is quite difficult to find related resources or documentation of Traditional Chinese version there. Not only most of the information on the webpage are out-of-date, but also those hyper-linked pages are couldn't find on the website of Microsoft Taiwan. It surprises me that it opened other ASP.Net webpage of Microsoft Taiwan when I clicked on "More Information" located at the corner of right bottom. Though it is a Traditional Chinese version webpage, most of hyper-linked pages are English version! Albert was frustrated by the horrible experiences.

So, my advice is that go to the Official Microsoft ASP.NET Site directly for up-to-date information. It saves lots of time for you!

It provides lots of resources at the Official Site. Especially, Starter Videos and "How do I" Videos are quit helpful for Albert, the beginner of ASP.Net. Microsoft provides files introduced by those videos include VB and C#. VB is used in those videos according to Albert's experience.

Because of there is problem between video image and audio for MPEG-4 files, Albert suggests to click "Download the video" for downloading WMV files in stead of MPEG-4.

Gadget & Widget

2008-07-12T20:26:00.000+08:00

中文版(點這裡)

The Gadgets of Google and Widgets of Yahoo are desktop tools which are composed by Javascript mainly, and provide handy/fun functions. Both of Google and Yahoo provide support information on their own website. Visit Google Desktop and Yahoo! Widgets for more details. It is quite different between Gadgets and Widget for installation. Administrator privilege is needed for installing Google Desktop and user privilege for Yahoo! Widget. I brought this up is because that the laptop I'm using belongs to the company and I do not possess administrator privilege. It seems that The Yahoo! Widget is my only choice!

Make Your Choice Carefully

Just a small part of those Gadgets or Widgets on their websites were developed by their own teams, most of desktop tools were composed by so-called "third party", it might just like you or someone else. And the quality might different between those little desktop tools. You might know that it takes system resources while running (on a computer). It is possible that a Gadget/Widget grabs system resources more than you thought if the author (of the desktop tool) did not consider about system performance carefully.

Develop Your Own Desktop Tools/ A Platform for Practicing Javascript Programming

Have you ever thought about what inside these desktop tools are? Google and Yahoo provide a lot of resources for developers. And they might intent to interest you for your taking part in developing their desktop tools. Google provides a SDK (Software Develop Kit) and lots of information on websites. Yahoo supplies a tool application Widget Converter, for packing/unpacking Yahoo! Widget, and tutorial documents and reference manuals. Furthermore, you can decompress those Gadgets and Widgets that download from their websites as example programs, if you are interested.

Different Between Gadget and Widget
	Google Gadget	Yahoo Widget	Remark
Pack File	Zip File/Flat Format File	Zip File	Widget converter is for Flat format Yahoo! Widget.
Ext. File Name	Widget	gg
Type of Main File	*.kon	Main.xml	XML(Extensive Markup Language) format
Tool App.	Widget Converter	SDK (Software Develop Kit)

火狐狸 3 (Firefox 3)即將登場!

2008-06-15T14:57:00.000+08:00

功能強大的火狐狸3(Firefox 3)的即將在六月十七號登場。

Mozilla已經把下個星期二(June 17)定為火狐狸的下載日(Download Day)。希望在下載日當天24小時內，為單日軟體下載次數締造新的金氏世界記錄(Guinness World Record)！

(下載自CNet)

Firefox 3它標榜比以前更安全、更快速以及更聰明。它的新功能中最讓人期待的應該是它所說的 "閃電般的執行效率(Lightning fast performance)" 以及它的安全功能。呃，Lightning fast performance....！\:0

不管如何，亞伯特十分的樂意看到這個由支持原始碼開放的機構所開發出來的軟體，不但是好用，而且足以跟微軟抗衡！就讓咱們拭目以待吧..... 想要在第一時間下載Firefox3，或者支持免費、開放原始碼的軟體，可以到下面這個網站去聲援它。留下您的email帳號，Mozilla會把相關的訊息通知您哦！

簡單易用的線上(Web-Base)影像編輯軟體FotoFlexer

2008-06-01T19:21:00.000+08:00

基本上，要用Photoshop得先付上一筆銀子，可能還得花一些磞子到補習班去上個幾個小時的課程，學一些基本技巧。甚至，有些人可能學一大堆用不上的東西，過久了也忘了！這些在日常生活上，平民百姓之家都是正常得不得了的事情。像我們這種買不起Photoshop，但是做報告、網頁需要處理影像檔，或是想要小小的修飾一下自己的照片，卻苦苦找不到適當軟體可以使用的升斗小民有福了！最近CNet就一口氣介紹了三款Free(免費)的影像處理軟體， Paint.NET FotoFlexer GIMP 有興趣而且想練練英文聽力的不妨參考一下的CNet上的影片...

拜軟體技術的進步之賜，Web-Base的應用程式造福了不少的網民。像是Google Document就是一個很好的例子。在上述的三款應用軟體中，亞伯特就特別的試用了FotoFlexer，它就是一款Web-Base Application。使用者不用下載、安裝就可操作這個應用軟體了！而且只需要簡單的操作，就可以達到不錯的效果....

經過亞伯特小試了之後發現，修改過的影像好像有"縮水"的現象！亞伯特上載的影像是2048X1536；結果，經過編輯之後，下載回來的卻只有638X479！未免差太多了.... :0<

不過，話說回來，至少它是Free的！不是很滿意，但勉強可以接受吧...

它還支援多國語言的，其中就包括繁體中文，不錯吧！只要在首頁的下方選擇繁體中文就行了(小遺憾是，代表繁體中文的旗子用錯了！:0<)。

至於登錄，您只要使用email的帳號註冊之後，就可以馬上使用了。你所要編輯的影像檔案，可以是放在網路上的相簿，像是MySpace、facebook或是Picasa等等，當然您也可以直接把您的圖檔上傳到FotoFlexer去編輯，應該是蠻方便的。

有空的話不妨三款都試試看，再把心得分享一下哦！:0)