Use Linq to obtain a unique list of properties from a list

Use the Distinct operator:

var idList = yourList.Select(x=> x.ID).Distinct();

Linq calculate average of a list C#

Only one line of code will do it:

List<float> f = new List<float>();

for (int i = 0; i < 10; i++)

{

    f.Add((float)i);

}

float ave = f.Aggregate((acc, cur) => acc + cur) / f.Count;

Console.WriteLine(ave);

How to play audio files on a particular soundcard C#

I have been working on playing audio files on particular audio devices for a few days. On windows platform. the [C#]using Microsoft.DirectX.AudioVideoPlayback; only works for the default audio device. We need to work on a lower layer, using DirectShow.

I will post the detail of the implementation a few days later.

Get regex matched strings (Regex Capture) C#

Program that uses Match [C#]

using System;
using System.Text.RegularExpressions;

class Program
{
    static void Main()
    {
 // A
 // The input string we are using
 string input = "OneTwoThree";

 // B
 // The regular expression we use to match
 Regex r1 = new Regex(@"One([A-Za-z0-9\-]+)Three");

 // C
 // Match the input and write results
 Match match = r1.Match(input);
 if (match.Success)
 {
     string v = match.Groups[1].Value;
     Console.WriteLine("Between One and Three: {0}",
  v);
 }
    }
}

Output Between One and Three: Two

UI String Matching in XAML and CS

A few month ago, we were doing String Localization for our software. It is lame for us to manually find the strings in the .cs and .xaml files and replace them with localization resource files.

So I look for help from REGEX, which is always helpful when dealing with strings.

Below is the regex to match UI String in xaml and cs files:

for .cs files:

^(~(ArgumentNullException|AddCMEventLog|//|dw\.add|OnPropertyChanged|Assembly\:|\[System\.|this\.RaisePropertyChanged|GeneratedCodeAttribute|throw\ new\ Exception).)+".*"(~(ArgumentNullException|AddCMEventLog).)+$

for .xaml files:

(Title="[^{])|(\ Text="[^{])|(Content="[^{])|(Header="[^{])|(ToolTip="[^{])|(Label="[^{])|(\ Value="[^{])|(Description="[^{])|(\>[^<>]+\<)

This may work in Visual Stdio only

When you want to import dll

using System.Runtime.InteropServices;//DLLimport

[DllImport("winmm.dll", SetLastError = true)]

How special var is in C#, var can't be the type of property of class C#

var is static typed - the compiler and runtime know the type - they just save you some typing... the following are 100% identical:

var s = "abc";
Console.WriteLine(s.Length);

and

string s = "abc";
Console.WriteLine(s.Length);

Finding an ancestor and children of a WPF dependency object

Below are from : http://www.hardcodet.net/2008/02/find-wpf-parent

This is a simple snippet which helps you to find a specified parent of a given WPF dependency object somewhere in its visual tree:

(Snippet updated 2009.09.14)

/// <summary>
/// Finds a parent of a given item on the visual tree.
/// </summary>
/// <typeparam name="T">The type of the queried item.</typeparam>
/// <param name="child">A direct or indirect child of the
/// queried item.</param>
/// <returns>The first parent item that matches the submitted
/// type parameter. If not matching item can be found, a null
/// reference is being returned.</returns>
public static T TryFindParent<T>(this DependencyObject child)
    where T : DependencyObject
{

Mercurial .hgrc

[ui]
username = Steven You <email>
[hostfingerprints]
bitbucket.org = 81:2b:08:90:dc:d3:71:ee:e0:7c:b4:75:ce:9b:6c:48:94:56:a1:fe
[extensions]
color =

Read binary in Hex

$ hexdump dog

or

$ cat dog | xxd

od -x can be used in mac, but the hight byte and low byte position is different

Mac Dev Utilities

/Developer/Applications/Utilities/PackageMaker.app/Contents/MacOS

C# Invoke particular EventHandler in InvocationList

I am trying to get particular EventHandler get fired.

Event ProjectChanged was hooked by several EventHandlers

public static event EventHandler ProjectChanged;

foreach (var eventHandler in ProjectChanged.GetInvocationList())

{

    if (eventHandler.Method.Name == "UserContext_ProjectChanged")

    {

        eventHandler.DynamicInvoke(null,null);

    }

}

String to Guid in C#

public static Guid StringToGUID(string value)

{

    // Create a new instance of the MD5CryptoServiceProvider object.

    MD5 md5Hasher = MD5.Create();

    // Convert the input string to a byte array and compute the hash.

    byte[] data = md5Hasher.ComputeHash(Encoding.Default.GetBytes(value));

    return new Guid(data);

}

configure git with color

To display color in the output of git diff, you need to configure git. Try running

$ git config --global color.diff true

to set your $HOME/.gitconfig appropriately.
To enable color for all:

$ git config --global color.ui true

Popular Command Lines for Linux

The original article are in three parts:

• Part I: Top Ten One-Liners from CommandLineFu Explained
• Part II: The Next Ten One-Liners from CommandLineFu Explained
• Part III: Another Ten One-Liners from CommandLineFu Explained
• Part IV: Yet Another Ten One-Liners from CommandLineFu Explained

In my post, part_1, part_2, part_3, part_4

I love working in the shell. Mastery of shell lets you get things done in seconds, rather than minutes or hours, if you chose to write a program instead.
In this article I’d like to explain the top one-liners from the commandlinefu.com. It’s a user-driven website where people get to choose the best and most useful shell one-liners.

WPF GridViewColumn Width 100 percent

<local:ListViewEx.View>

    <GridView ColumnHeaderContainerStyle="{StaticResource CustomHeaderStyle}">

        <GridViewColumn Header="xxx" 
             Width="{Binding RelativeSource={RelativeSource FindAncestor, 
             AncestorType=ListView}, Path=ActualWidth}">

             <GridViewColumn.CellTemplate>

Turning Vim into a modern Python IDE

http://sontek.net/turning-vim-into-a-modern-python-ide

Use screen run background program in linux server

$screen
$run batch command
Press Ctrl-a,d

$screen -ls

There are screens on:

15914.pts-1.centos (Detached)

15887.pts-0.centos (Detached)

2 Sockets in /var/run/screen/S-root.

$screen -r 15914

(& , nohup)

Amazon AWS EC2 web server & git server set up

http://codelikezell.com/setting-up-rails-mysql-php-apache-and-git-on-ec2/
https://help.ubuntu.com/community/EC2StartersGuide
http://paulstamatiou.com/how-to-getting-started-with-amazon-ec2

OpenCV material

http://en.wikipedia.org/wiki/Blob_extraction
http://www.neuroforge.co.uk/index.php/binary-images-with-opencv
http://opencv.willowgarage.com/documentation/python/histograms.html#createhist

PYTHON iterate all files in a directory

To iterate through all the files within the specified directory (folder), with ability to use wildcards (*, ?, and [ ]-style ranges), use the following code snippet:

PLAIN TEXT

PYTHON:

1. import os
2. import glob
3.  
4. path = 'sequences/'
5. for infile in glob.glob( os.path.join(path, '*.fasta') ):
6.     print "current file is: " + infile

If you do not need wildcards, then there is a simpler way to list all items in a directory:

PLAIN TEXT

PYTHON:

1. import os
2.  
3. path = 'sequences/'
4. listing = os.listdir(path)
5. for infile in listing:
6.     print "current file is: " + infile
   
   

PYTHON RuntimeError: maximum recursion depth exceeded in cmp

if your python code produces the following error: “RuntimeError: maximum recursion depth exceeded in cmp,” try adding this line to the beginning of your code:

sys.setrecursionlimit(1500)

note that python’s default limit is 1000.

opencv

g++ hello-world.cpp -o hello-world \
    -I /usr/local/include/opencv -L /usr/local/lib  \
    -lm -lcv -lhighgui -lcvaux

c++ find_obj.cpp -o o -I /usr/local/include -L /usr/local/lib -lopencv_core -lopencv_imgproc -lopencv_highgui -lopencv_ml -lopencv_video -lopencv_features2d -lopencv_calib3d -lopencv_objdetect -lopencv_contrib -lopencv_legacy -lopencv_flann

JumpList in Taskbar WPF, eg: recent items

http://msdn.microsoft.com/en-us/library/ff770767.aspx

Color grep in terminal

alias grep='GREP_COLOR="1;37;41" LANG=C grep --color=auto'

TODO: this week

http://code.google.com/appengine/docs/python/gettingstarted/devenvironment.html
http://blog.copyninja.info/2010/04/vim-auto-complete-feature-for-gae.html
http://pydev.org/
http://code.google.com/p/google-app-engine-samples/

http://cgi.cse.unsw.edu.au/~cs9315/11s2/pracs/p01/index.php
http://cgi.cse.unsw.edu.au/~cs9315/11s2/pracs/p02/index.php
http://cgi.cse.unsw.edu.au/~cs9315/11s2/exercises/ex01/index.php
http://www.gosteven.com
http://www.ryarc.net/devblog

!$ in command

$vim testfile.txt

then $cat !$ will give u the testfile.txt

Check the size of the directory -- du -sh *

$du -sh *

Icon Render WPF

RenderOptions.BitmapScalingMode="NearestNeighbor"                            RenderOptions.EdgeMode="Aliased"

Text Trimming and ToolTip bind to itself

TextTrimming="CharacterEllipsis" TextWrapping="Wrap" ToolTip="{Binding Text, RelativeSource={RelativeSource Mode=Self}}

VIM increase number, increase alpha

Press Ctrl+A increase the number under cursor.

:set nrformats=alpha

can help you increase character.

CRLF

The origin of the older computer term "CRLF" - which redirects to this Newline article - or "Carriage Return [and] Line Feed", derives from standard manual typewriter design, whereby at the end of a line of text the typist pushes a lever at the left end of the carriage to return it to position for beginning the next line.

Autumn of Agile Screencast Series

Guys
http://www.autumnofagile.net/
this is very interesting & easy to understand agile video
--vishal

eclipse comments short cut

Shortcut	Command	Description
Ctrl+/	Toggle Comment	Add/remove line comments (//…) from the current line. The position of the cursor can beanywhere on the line. Works with multiple selected lines as well.
Ctrl+Shift+/	Add Block Comment	Wrap the selected lines in a block comment (/*… */).
Ctrl+Shift+\	Remove Block Comment	Remove a block comment (/*… */) surrounding the selected lines.
Alt+Shift+J	Add Javadoc Comment	Add a Javadoc comment to the active field/method/class. See the notes below for more details on where to position the cursor.

Cool stuff in .NET 4.0: System.Threading.Tasks.TaskScheduler

private void Save()

{

    System.Threading.Tasks.TaskScheduler uiScheduler = System.Threading.Tasks.TaskScheduler.FromCurrentSynchronizationContext();

    System.Threading.Tasks.Task<ErrorEnum>.Factory.StartNew(() =>

    {

        ErrorEnum callResult = ErrorEnum.OK;

        try

        {

            IsIdle = false;

            callResult = (ErrorEnum)DataContext.DomainRepository.SaveDomain(_domain);

            if (callResult != ErrorEnum.OK)

            {

                // If remote saving fails, rollback all the changes

                Rollback();

            }

            else

            {

                // If remote saving succeeds, save changes to local db

                SaveChangesToLocalDB();

            }

            return callResult;

        }

        catch (Exception ex)

        {

            LogManager.AddCMEventLog("DomainSettingsViewModel.Save", ex);

            // If anything goes wrong, rollback all the changes

            return ErrorEnum.LocalFatalAnonymousError;

        }

        finally

        {

            IsIdle = true;

        }

    }).ContinueWith(task => ShowResult(task.Result), uiScheduler);

}




This running tasks in background thread, then call UI thread to execute the ShowResult() function, Just like UIDispatcher

Proxy server

http://www.youngzsoft.net/ccproxy/proxy-server-download.htm

CC Proxy

perl send email cgi

Lots of tutorials about sending email with perl depend on some uncommon libs.
There is a common way to do so:

use Net::SMTP::SSL;


sub send_mail {
    my $to      = $_[0];
    my $subject = $_[1];
    my $body    = $_[2];

perl session cgi

http://search.cpan.org/dist/CGI-Session/lib/CGI/Session/Tutorial.pm


$session = CGI::Session->load() or die CGI::Session->errstr;
if ( $session->is_expired ) {
    die "Your session expired. Please refresh your browser to re-start your session";
}
if ( $session->is_empty ) {
    $session = $session->new();
}

print $session->header();

#save into session

$session->param('username',$username);

#read from session

$variable = $session->param('username');

Dig into VIM

Input :h! in vim , what u find!?
Then :h 42 ....

quick command : http://jrmiii.com/attachments/Vim.pdf

vim cookbook: http://vim.runpaint.org/

U can also use vim in eclipse http://eclim.org/

Make vim easier to use: http://vim-taglist.sourceforge.net/installation.html (CTAGS needed)

Split screen :http://coolshell.cn/articles/1679.html

Make vim for perl : http://www.thegeekstuff.com/2009/01/make-vim-as-your-perl-ide-using-perl-supportvim-plugin/
Hot Keys : http://lug.fh-swf.de/vim/vim-perl/perl-hot-keys.pdf
#perltidy is a powerful tool to auto format the code, the hot key is \ry

Scripts : http://www.vim.org/scripts/script_search_results.php?order_by=rating

A modern vim for new guys: http://cream.sourceforge.net/index.html

Java sort list -- Collections.sort sample

public static void Sort(List<Movies> items) {

Collections.sort(items, SENIORITY_ORDER);

}

static final Comparator<Movies> SENIORITY_ORDER =

        new Comparator<Movies>() {

public int compare(Movies e1, Movies e2) {

if (e1.getReleaseDate().after(e2.getReleaseDate()))

return 1;

else

return -1;

}

};

New View of Blogger is awesome!!

Set Window on top of others

The correct way to implement a modal window is by setting  this.Owner = Application.Current.MainWindow; in the XAML, and show the dialog by using DialogName.ShowDialog();

perl!

Perl

• Perl Regular Expression -Quick Reference — PDF
• Perl Cheat Sheet
• Perl Cheat Sheet
• Perl 5 Cheat Sheet
• Perl Quick Reference Card — PDF
• Perl Regexp Quick Reference Card — PDF

interactive shell in vim

:sh
exit
--
Ctrl-z
fg
--
Bang!
:! wc %
:! php5 -l %
:r textfile
:r ! ls -1 /home/user/directory
:r ! w3m http://en.wikipedia.org/wiki/Vi -dump

vimrc

set nocompatible
set mouse=a
behave mswin

TextTrimming ToolTip in WPF

<TextBlock Text="{Binding State}" TextTrimming="CharacterEllipsis" Foreground="#6D6D6D"
                                                           ToolTip="{Binding Text, RelativeSource={RelativeSource Mode=Self}}"/>

Change ubuntu default shell to bash

Found out that the C-style for loop does not work in ubuntu shell. After a few google search, answer is at below:
C-style for loop on works In bash (since version 2.04)
The sh command in /bin/sh is a symbolic link to /bin/dash:


steven@steven-laptop:/bin$ ls -l sh
lrwxrwxrwx 1 root root 4 2010-05-03 06:48 sh -> dash

Use 

$sudo ln -sf /bin/bash /bin/sh

to replace

To change the login shell, use the command $chsh

Conditional Operations

Let's look at the if/then/else construct in a Bash shell script and see how to control the flow of a script with conditional logic. The general form of if/then/else is shown here, with the actual syntax shown in boldface and the parts you must supply in normal type:
if [ condition is true ]
then
execute these commands
else
execute those commands

VIM set tab key == 4 spaces

in your .vimrc:

set smartindent
set tabstop=4
set shiftwidth=4
set expandtab

Installing Apache Tomcat 6 on Mac OS X 10.5 Leopard or Mac OS X 10.6 Snow Leopard

Installing Apache Tomcat 6 on Mac OS X 10.5 Leopard or Mac OS X 10.6 Snow Leopard

MileStone for next week 14 Mar

VNC NAT traversal
VNC proxy
TCP hole-punching
RDP command-line
libjingle
Execute a Command in C#

ListView ObservableCollection Selection

I have ListView with GridView inside (in order to divide ListView for some columns). I bind ObservableCollection of some objects with that ListView.DataContext when main UserControl is loaded. Items show up but when i create two objects which fields have same values (and put them to observable collection), that new items show up in ListView. Problem is that, when user clicks and select one of the new item - both select.

When value of one of mentioned objects changes (and is different) problem doesn't exist, ListView treat them as it should.

Regular Expression

Search for REGEXP

The filter

head t.txt; echo ... tail t.txt

%sort -r +1-2 t1_data.txt
%sort -r -n -k2 t1_data.txt
%grep ' [6-9]' t1_data.txt

C# Write Access Check

        /// <summary> Checks for write access for the given file.

        /// </summary>

        /// <param name="fileName">The filename.</param>

        /// <returns>true, if write access is allowed, otherwise false</returns>

        public static bool WriteAccess(string dire)

        {

            // Get the access rules of the specified files (user groups and user names that have access to the file)

            var rules = Directory.GetAccessControl(dire).GetAccessRules(true, true, typeof(System.Security.Principal.SecurityIdentifier));

            // Get the identity of the current user and the groups that the user is in.

            var groups = WindowsIdentity.GetCurrent().Groups;

            string sidCurrentUser = WindowsIdentity.GetCurrent().User.Value;

            // Check if writing to the file is explicitly denied for this user or a group the user is in.

            if (rules.OfType<FileSystemAccessRule>().Any(r => (groups.Contains(r.IdentityReference) || r.IdentityReference.Value == sidCurrentUser) && r.AccessControlType == AccessControlType.Deny && (r.FileSystemRights & FileSystemRights.WriteData) == FileSystemRights.WriteData))

                return false;

            // Check if writing is allowed

            return rules.OfType<FileSystemAccessRule>().Any(r => (groups.Contains(r.IdentityReference) || r.IdentityReference.Value == sidCurrentUser) && r.AccessControlType == AccessControlType.Allow && (r.FileSystemRights & FileSystemRights.WriteData) == FileSystemRights.WriteData);

        }