狗吠火車

How to check the distribution and kernel version of Linux?

2012-02-08T18:28:00.000-08:00

$ cat /etc/*-release It will tell you the distribution name and version.
$ lsb_release -a Same as above.
$ uname -mrs It will tell you the linux kernel version and type (x86 or x64).

How to adjust the output quality when using Handbrake to convert DVDs to MP4/Mkv

2012-01-14T07:05:00.000-08:00

There are 3 methods which can do the same thing to you.
They are easy and helpful.

1. Set the estimated output file size:
Handbrake with calculate the best bitrate for you. For DVDs with the best converting quality. Set the output file size equals or slightly smaller than the original DVD size. That can yield the best output quality.

2. Set the average bitrate:
480P(720x480) h.264
excellent bitrate=4266 kbps,
good bitrate=2346 kbps,
normal bitrate=1493 kbps,

480P(720x480)mpeg4
excellent bitrate=4665 kbps,
good bitrate=2565 kbps,
normal bitrate=1632 kbps.

3. Set the constant quality:
For preserving the DVD quality, set RF=20.
For smaller output file size, set RF=28.

Linux/Unix下用SCP傳輸檔案之用法

2011-12-22T23:22:00.000-08:00

傳檔案過去遠端主機

scp -p source.file user@DomainName:/TargetPath/

抓檔案過來

scp user@DomainName:/SourcePath/file /home/user/TargetPath

2011-12-20T17:54:00.000-08:00

How to update/install Firefox 9.0 in Ubuntu?

新增Firefox 9.0 repository
sudo add-apt-repository ppa:mozillateam/firefox-next
更新套件版本資料
sudo apt-get update
更新系統套件版本，或者直接安裝Firefox 9.0
sudo apt-get upgrade or sudo apt-get install firefox
搞定收工

移除Gnome Class介面中Top Bar的捷徑圖示

2011-12-20T00:04:00.001-08:00

Question: How to remove the icon from the top bar in Gnome classic interface?

Ans: Alt+滑鼠右鍵。

在Linux與PHP環境下開發多國語言介面網站

2011-09-28T18:46:00.000-07:00

不囉嗦，最直接的方式，使用gettext，
參考資料如下：

1. 於 Windows 使用 PHP + GetText 來實做多國語系支援(I18N)
2. Gettext mo 轉回 po 和 PHP 讀取 mo 檔
3. PHP 網頁訊息國際化與 gettext 使用經驗
4. 透過Gettext for PHP快速做出多國語系程式
5. How to get PHP and gettext working (ubuntu, debian)

空字串與Null

2011-08-22T00:12:00.000-07:00

聽說在Oracle DB中，空字串==Null是成立的，
但是在其他地方不是。

空字串：一個字串沒有東西，但仍有字串結尾，例如/0。
Null：什麼都沒有。

自己做了一點小實驗，
string aaa="";
string bbb=null;

對aaa與bbb取長度，則aaa=0，bbb不給取，編譯就會出現exception。
對aaa與bbb進行==null判斷，aaa為false, bbb為true。

C# command line parameters

2011-08-21T19:14:00.000-07:00

Command Line Parameters Tutorial
http://msdn.microsoft.com/en-us/library/aa288457%28v=vs.71%29.aspx

簡單的說，args是拿來取command line使用時的參數數目，
所以可以用args.length取得參數數目，
取用方法就args[0]、args[1]依此類推。

型別之所在，錯誤之所在

2011-08-16T01:18:00.001-07:00

原來DataSet, DataTable, DataRow都是沒有型別的，怎麼接資料都可以，轉成Entity就不行，需要認真注意型別，切記切記。

KeyDown與KeyPress的差異

2011-08-10T23:47:00.000-07:00

KeyPress: invoked only for character (printable) keys

KeyDown: raised for nonprintable such as Control, Shift, etc.

c#中使用ComboBox顯示key, value的方法

2011-08-04T03:23:00.000-07:00

首先，使用Dictionary<TKey, TValue>宣告一組key與value的對應值，
語法如下：

            Dictionary statusList = new Dictionary();
            statusList.Add("A", "Apple");
            statusList.Add("B", "Bird");
            statusList.Add("C", "Cat");

            comboBox.DataSource = new BindingSource(statusList, null);
            comboBox.ValueMember = "KEY";
            comboBox.DisplayMember = "VALUE";
            comboBox.SelectedIndex = comboBoxStatus.Items.IndexOf(new KeyValuePair("A", "Apple"));

之後再用下行語法：
comboBox.SelectedIndex = comboBoxStatus.Items.IndexOf(new KeyValuePair("A", "Apple"));

就可以讓ComboBox顯示預設的字串，但實際使用者回傳的key是前面的A、B或者C，取值的語法如下行：
string reportState = ((KeyValuePair)comboBox.SelectedItem).Key

Static參數在程式中的用途

2011-08-01T02:55:00.000-07:00

函數中的static variable

被宣告成static 的變數，其實就是 global 的了，變數不會隨著函數結束而消逝，只是因為是宣告在某Function 裡，所以只能在某Function 裡用。
在函數中，static variable只會被初始一次，函數重新被呼叫時，不會被重新初始，等於可以用此static variable在連續呼叫的相同函數中傳遞數值。

Class中的static variable

把class中的member variable 宣告成 static，代表此variable與「class」相關連」，而不是「與物件相關連」。此variable可獨立配置記憶體，獨立於 class 的任何物件而存在，這個 class 產生的所有物件共用使同一個 static member variable，甚至不需要有物件也能夠被使用。
白話點講，所有的class所產生的instance，皆可使用此static member variable，等於是所有instance之間的共用變數。

static class

若把整個class也宣告成static，則類別中所有method也要是static。

解決Visual Studio專案，執行時產生0x8007000B錯誤代碼

2011-08-01T00:42:00.000-07:00

0x8007000B錯誤代碼，其意思為載入了格式不對的dll檔。

若未更改預設設定，基本上visual studio會依照系統的版本去編譯程式，
亦即跑在x86系統，就編成x86程式，跑在64bit環境，就編成x64程式。

所以遇到這問題時，到專案->[專案名稱]特性中，Build tab下，把平台目標改成x86，
確保編譯輸出的結果是想要的，就可以避免0x8007000B問題。

C# 除錯設定

2011-07-14T20:21:00.000-07:00

參考這篇文章，果然我還有很多要學的。

1. Step Into (F11) : 逐行偵錯，遇到可以函式則繼續進入逐行偵錯。

2. Step Over (F10)：逐行偵錯，但遇到函式則直接繼續執行下一行，不進入函式逐行偵錯。

3. Step Out (Shift + F11) ：脫離函式，在使用逐行偵錯時，進入處理函式後如果想返回前一個 Call Stack 呼叫函式時使用

4. Continue (F5)：直接執行接下來的程式碼，直到遇到下個中斷點。

5. Run to Cursor (Ctrl + F10)：繼續執行程式碼，但會中斷於游標所在的程式碼。

如何轉換Visual Studio 2010與2008之檔案？

2011-06-27T04:01:00.000-07:00

As title,

For <PROJECT_NAME>.sln:
1. Open the solution file in your favorite text editor (ex: notepad++).
2. Find the Following:
Microsoft Visual Studio Solution File, Format Version 11.00.
# Visual Studio 2010.
Replace with:
Microsoft Visual Studio Solution File, Format Version 10.00. (I)
# Visual Studio 2008. (II, optinal)

For <Project_name >.csproj/vbproj:
1. Open project file in your favorite text editor (ex: notepad++).
2. Find the Following:
<Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">.
Replace with:
<Project ToolsVersion="3.5" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">. (III)

Properties in C#

2011-06-27T01:13:00.000-07:00

A property is a member that provides a flexible mechanism to read, write, or compute the value of a private field. Properties can be used as if they are public data members, but they are actually special methods called accessors. This enables data to be accessed easily and still helps promote the safety and flexibility of methods.

範例一：

class TimePeriod
{
    private double seconds;

    public double Hours
    {
        get { return seconds / 3600; }
        set { seconds = value * 3600; }
    }
}


class Program
{
    static void Main()
    {
        TimePeriod t = new TimePeriod();

        // Assigning the Hours property causes the 'set' accessor to be called.
        t.Hours = 24;

        // Evaluating the Hours property causes the 'get' accessor to be called.
        System.Console.WriteLine("Time in hours: " + t.Hours);
    }
}
// Output: Time in hours: 24

以上是MS的解釋，主要連結在此。

範例二：

舊用法：要有一個欄位變數(Field Variable)：age ，get還要return，set要收欄位變數的值，
private int age;

public int Age

get

        return age;

set

        age = value;

現在！免！
按下面的語法寫就可以，不過get與set兩者都要存在才行。

public string Age{ get; set; }

若是要設定唯讀

public string Age{ get; private set; }

另一個網路上的解釋，連結在此。

個人的解釋：提供一個界面，把class中的function當作變數來用。因為當作變數，所以就只要寫好兩個功能，set（存）與get（取），寫好後，就把function當變數直接用就是，算是兼顧彈性與封裝性質的偷吃步。function名稱與函數名稱若不同時，就等於是寫public function存取private variable。function名稱與variable名稱，若只差第一個字母之大小寫時，預設就是用此function存取此variable，如同上面的範例二。

一個對物件相當清楚的解釋

2011-06-22T01:13:00.001-07:00

Namespace: A category or brand of cars. Note that the brand really doesn't have to dictate how the car is built. You can't say a Honda always have four doors, or that it always has 4wd. Such specifics is up to the class to dictate. Rich.Carpenter's post explains the purpose of namespaces very good.
Class: Blueprint for how to build a specific car.
Object: An actual car (instance) created from the car blueprint (the class)
Method: Something a user of the car can make it do. Start(), IncreaseThrottle(), Break(), OpenDoor() etc.
Property: Attributes, information and building blocks which the car contains. E.g. Total running miles, color, steering wheel dimension, stereo system etc etc.

Some concepts which could seem more advanced to you. Maybe overkill right now, but read it if you're interested:

Inheritance: When a class is based on another class and adds some more specific details. A line of inheritance usually goes from the most common and general aspect, all the way down to a point where it makes no more sense to be more specific. Example of this in the context of animals: Animal->Mamal->Rodent->Rat->RattusNorvegicus
Aggregates: Properties that "builds" the object. E.g. "This car is an aggregation of four wheels, a chassi, an engine, etc".
Attribute: Properties that describe the object, usually not part of its physical construction. E.g. Color, top speed, engine volume etc.
Encapsulation: The concept of concealing certain properties from the user, or to protect certain properties from being used incorrectly (and thereby damaging the object). E.g. You don't expose the gear-property of a car class to be altered freely. You encapsulate it and make sure Clutch() is called before SetGear().
Overriding: If a class inherits from another class, it also inherits methods from that class. Overriding is basically when the inheriting class replaces the implementation of such a method with its own required behaviour. Example of usage in next point.
Polymorphism: A difficult concept to grasp until you start using it practically. It means referring to a very specific kind of object, by using a generic reference which allows you to ignore the specific type (when you don't need to know it). E.g. If you wan't to "read" the license plate number property of every vehicle in a parking lot, you don't really care what the brand is, or even if it's a trailer or motorcycle or whatever. To be able to do this, we make sure the license plate number is a property in the most general class in the inheritance line (probably the Vehicle class). So you only have to deal with all the objects in a list by referring to them as Vehicles and then call Vehicle::GetLicensePlateNumber(). Any vehicle requiring some special handling to retrieve the number can implement this behaviour by overriding the method and make it behave as required. So a wide range of object types can be used as if they were of the same type, but can behave differently.

Google搜尋進階用法(2)

2011-06-21T02:11:00.000-07:00

不完整字句搜尋
ex: "Taiwan is * country"
會出現Taiwan is an independent country等等字句之網頁。

看網站目錄的下載
ex: "index of /"AVI
找出網頁有提供目錄，且目錄中有avi檔案

Google搜尋進階用法(1)

2011-06-21T01:44:00.000-07:00

inurl: 搜尋在網址中有的文字。
ex: inurl:php language
說明:搜尋網址中有php，網頁內文中有language

allinurl:搜尋在網址列中的文字，但全部都要在網址中
ex allinurl:php cgi language
說明:php，cgi與language三者都要在網址中

intitle與allintitle同上，只是把網址改成title區

如何在Firefox Nightly 7.0a1使用舊版Add-on?

2011-06-01T02:41:00.000-07:00

Google查到的，在about:config中新增boolean字串 "extensions.checkCompatibility.nightly"並設定其值為"false"。

來源文章

2011/4/10今日檢討

2011-04-09T09:54:00.000-07:00

1. 講話太aggressive，就算我知道很多事情，也沒必要一定要講出來，講出來，讓別人知道懂很多，這樣很重要，很好嗎？
2. 為何會對學弟講錯一個東西，有這樣的對答酸別人呢？嗆很人很爽，但是這樣是我想要的嗎？

Think before you speak.
自省之。

建立一個新的MSN聯絡人分類

2011-04-08T06:43:00.000-07:00

這個分類就叫做『沒誠意』，
歡迎第一位居民入住，
我不會就這樣block此位聯絡人的，
這樣只會顯得我沒氣度。

孤獨

2011-04-06T10:04:00.000-07:00

原來我只是害怕孤獨，
今後課題，
害怕孤獨，承認孤獨，接受孤獨，習慣孤獨，與孤獨當朋友，
何必為了害怕孤獨，就約沒誠意，不是朋友的朋友呢，
Yes，我就是在說你，Exho，從今天起，我不再把你當朋友了。