STL 將「在資料上執行的操作」與「要執行操作的資料分開」
MapReduce is a programming model and an associated implementation for processing and generating big data sets with a parallel, distributed algorithm on a cluster.
「流」是一連串從I/O設備讀寫的字符（Byte）。
需要使用者互動的軟體必須儘快回應使用者的活動，以便提供豐富的使用者經驗。不過，同時它也必須執行需要的計算以儘快提供使用者資料。在個人目前的工作領域，使用者體驗並非放在第一(甚至是最後一名)，大部分時間都花在Coding工作處理常式（Routines），主要實現概念為狀態機(State-Machine)與多工處理(Multi-Task)，在Main Thread執行
class Program
{
static void Main(string[] args)
{
int state = 0;
Action __delegate = null;
Task __task = null;
IAsyncResult handle = null;
ConcurrentQueue exchange = new ConcurrentQueue();
int outValue = 0;
//the main state machine
Program.method();
while (state != 500)
{
switch (state)
{
case 0:
// use Task
__task = new Task(new Action(Program.method));
__task.Start();
state +=10;
break;
case 10:
// wait until task done
if (__task.IsCompleted)
state +=10;
break;
case 20:
// use thread pool
ThreadPool.QueueUserWorkItem((object foo)=>{
Program.method();
exchange.Enqueue(0); // enqueue some meaningfll result
},null);
state+=10;
break;
case 30:
//wait until method had been scheduled and executed
if (exchange.TryDequeue(out outValue))
state +=10;
break;
case 40:
// use delegate/IAsyncResult
__delegate = new Action(method);
handle = __delegate.BeginInvoke((IAsyncResult ar)=>
{
method();
__delegate.EndInvoke(ar); // you had to call this to release ar
},null);
break;
case 50:
// wait until method had been executed
if (handle.IsCompleted)
state = 500;
break;
default:
break;
}
Thread.Sleep(0);// yield to other thread to run
}//while
}
static void method()
{
//reflect the current thread
Console.WriteLine(System.Threading.Thread.CurrentThread.ManagedThreadId.ToString());
}
}
String __input = "Model:M1 Coordinates: X1.62 Y1.01 X9.53 Y2.3 X4.94 Y2.1 X8.55 Y3.15 X2.56 Y1.25 X5.57 Y2.72"; String __patternUnnamed = "Model:[\\\\w]+[\\\\s]+Coordinates:[\\\\s]+(X([-+]?[0-9]*\\\\.?[0-9]+)[\\\\s]*Y([-+]?[0-9]*\\\\.?[0-9]+)[\\\\s]*)+"; List若模式字串裡（）太多，或是覺得用INDEX標定群組可讀性太差，此時可以套入具名群組（Named Group）的概念，把（）所圈住的Symbol具名化：__coords = new List (); Match __matchUnnamed = Regex.Match(__input,__patternUnnamed); //----------------------------------- // Unnamed //----------------------------------- __coords.Clear(); for (int i = 0; i < __matchUnnamed.Groups[1].Captures.Count;i++) { // use X,Y group restore each coordinates float[] eachCoord = new float[]{0,0}; eachCoord[0] = float.Parse(__matchUnnamed.Groups[2].Captures[i].Value); eachCoord[1] = float.Parse(__matchUnnamed.Groups[3].Captures[i].Value); __coords.Add(eachCoord); } //check all coordinates Console.WriteLine(\"Unnamed\"); foreach (float[] item in __coords) { Console.WriteLine(String.Format(\"{0},{1}\", item[0], item[1])); }
String __patternNamed = "Model:[\\\\w]+[\\\\s]+Coordinates:[\\\\s]+(?X(? [-+]?[0-9]*\\\\.?[0-9]+)[\\\\s]*Y(? [-+]?[0-9]*\\\\.?[0-9]+)[\\\\s]*)+"; Match __matchNamed = Regex.Match(__input,__patternNamed); //----------------------------------- // Named //----------------------------------- //now we get the \"coord\" group __coords.Clear(); for (int i = 0; i < __matchNamed.Groups[\"coord\"].Captures.Count; i++) { // use X,Y group restore each coordinates float[] eachCoord = new float[]{0,0}; eachCoord[0] = float.Parse(__matchNamed.Groups[\"X\"].Captures[i].Value); eachCoord[1] = float.Parse(__matchNamed.Groups[\"Y\"].Captures[i].Value); __coords.Add(eachCoord); }
class utilities
{
/// <summary>
/// Used to store key-serializer
/// </summary>
/// <returns></returns>
private static Hashtable __dictionary = new Hashtable();
/// <summary>
/// Generate key according to contents of type list
/// </summary>
/// <param name="typeList"></param>
/// <returns></returns>
protected static int generateKey(List<Type> typeList)
{
//hash code summarize
return typeList.Sum(__type => __type.GetHashCode());
}
/// <summary>
/// Always fetch serializer from this function
/// (Never allocate by yourself)
/// </summary>
/// <param name="mainType"></param>
/// <param name="extraTypes"></param>
/// <returns></returns>
public static XmlSerializer getSerializer(Type mainType,Type[] extraTypes){
//merge the list
List<Type> __typeList = new List<Type>();
__typeList.Add(mainType);
__typeList.AddRange(extraTypes);
var key = generateKey(__typeList);
if (__dictionary.ContainsKey(key))
{
// this kind of serializer had been cached/used before ,
// get the cached serializer
return (XmlSerializer)__dictionary[key];
}
else
{
// never been used , need to create a new one and push into cache
XmlSerializer __serializer = new XmlSerializer(mainType,extraTypes);
__dictionary.Add(key,__serializer);
return __serializer;
}
}//getserializer
}//utilities
<project sdk="Microsoft.NET.Sdk">
<propertygroup>
<outputtype>Exe</outputtype>
<targetframework>netcoreapp1.1</targetframework>
</propertygroup>
<itemgroup>
<packagereference include="System.Collections" version="4.3.0">
<packagereference include="System.Collections.NonGeneric" version="4.3.0">
<packagereference include="System.Runtime.Extensions" version="4.3.0">
<packagereference include="System.Xml.XmlSerializer" version="4.3.0">
</packagereference></packagereference></packagereference></packagereference></itemgroup>
</project>
class stringUIEditor :
UITypeEditor
{
public override UITypeEditorEditStyle GetEditStyle(System.ComponentModel.ITypeDescriptorContext context)
{
return UITypeEditorEditStyle.Modal;
}
public override object EditValue(System.ComponentModel.ITypeDescriptorContext context, IServiceProvider provider, object value)
{
Form __form = new Form(); // allocating a form , used to show-up editable facility
TextBox __tb = new TextBox();
__form.Controls.Add(__tb);
__form.AutoSize=true;
__form.ShowDialog(); // show-up the form
return __tb.Text; //return the text value the user just input.
}
}
 |
| 從(...)呼喚的UIEditor |
 |
| PropertyGrid各顯示樣式控制對應屬性 |
class optionEnumConvertor :
EnumConverter
{
/// <summary>
/// Convert From String To Enum Type
/// </summary>
/// <param name="context" />
/// <param name="culture" />
/// <param name="value" />
/// <returns></returns>
public override object ConvertFrom(System.ComponentModel.ITypeDescriptorContext context, System.Globalization.CultureInfo culture, object value)
{
switch (value.ToString())
{
case "選項1":
return MyEnum.OPTION1;
case "選項2":
return MyEnum.OPTION2;
default:
return null;
}
}
/// <summary>
/// Convert From Enum Type To String Type
/// </summary>
/// <param name="context" />
/// <param name="culture" />
/// <param name="value" />
/// <param name="destinationType" />
/// <returns></returns>
public override object ConvertTo(System.ComponentModel.ITypeDescriptorContext context, System.Globalization.CultureInfo culture, object value, Type destinationType)
{
switch ((MyEnum)value)
{
case MyEnum.OPTION1:
return "選項1";
case MyEnum.OPTION2:
return "選項2";
default:
return null;
}
}
public optionEnumConvertor(Type type):base(type)
{
}
}
[DisplayName("想要選什麼？")] // much more human-readable?
[TypeConverter(typeof(optionEnumConvertor))]
public MyEnum Property3 { get; set; }
[TypeConverter(typeof(optionEnumConvertor))]
enum MyEnum
{
OPTION1,
OPTION2,
}
 |
| Enum轉String |
enum MyEnum
{
OPTION1,
OPTION2,
OPTION3,
}
class MyClass
{
public int Property1
{
get
{
return __innerVariableInteger;
}
set
{
// constrained range
if (value > 10 && value < 20)
__innerVariableInteger = value;
}
}
public string Property2
{
get
{
return __innerVariableString;
}
set
{
__innerVariableString = value;
}
}
public MyEnum Property3 { get; set; }
protected string __innerVariableString = "";
protected int __innerVariableInteger = 15;
}
 |
| 若是型別為Enum則會自動提供ComboBox選項 |
public int Property1
{
get
{
return __innerVariableInteger;
}
set
{
// constrained range
if (value > 10 && value < 20)
__innerVariableInteger = value;
}
}
你永遠沒辦法Key-in這範圍以外的值。
class MyClass
{
[Description("The input value range is 16-19")] //offered the description which would showed on the bar below
[Category("Catagory A")] // offered the folded categoring method
[DisplayName("Integer Parameter")] // offered the customised display name
public int Property1
{
get
{
return __innerVariableInteger;
}
set
{
// constrained range
if (value > 10 && value < 20)
__innerVariableInteger = value;
}
}
[Browsable(false)] //wont be showed on PropertyGrid
public string Property2
{
get
{
return __innerVariableString;
}
set
{
__innerVariableString = value;
}
}
[DisplayName("想要選什麼？")] // much more human-readable?
public MyEnum Property3 { get; set; }
protected string __innerVariableString = "";
protected int __innerVariableInteger = 15;
}
 |
|
static Func另外一個有趣的事情是，在CLR的記憶體模型中，delegateInstance = new Func (() => { Console.WriteLine("I was prisoned in Lambda!!!"); return 0; });
static int createLambda()
{
String theInstance = "I was created in createLambda()";
delegateInstance = new Func(() =>
{
Console.WriteLine(theInstance.ToString());
return 0;
});
return 0;
}
static int executeLambda()
{
delegateInstance();
return 0;
}
static void Main(string[] args)
{
createLambda();
executeLambda(); //' theInstance still kept, so that no NullReferenceException would raise
}
最後分享一個案例，若在Foreach中想要替陣列裡的每個物件創造對應的Lambda，在Lambda執行時，能反應陣列裡各物件的狀態（一個Lambda反應一個物件） 此時放在Lambda內的應該要用哪個具名參考？ static void Main(string[] args)
{
List theList = new List();
Random rnd = new Random();
Console.WriteLine("Peek answers");
for (int i = 0; i < 10; i++)
{
myClass instance = new myClass();
instance.myString = rnd.Next().ToString();
theList.Add(instance);
Console.WriteLine(instance.ToString());
}
Console.WriteLine("Peek over");
delegateInstance = null;
//myClass tempReference ; // option 2
foreach (myClass item in theList)
{
//myClass tempReference = item; // option 3
//tempReference = item;
delegateInstance += new Func(() =>
{
//Console.WriteLine(tempReference.ToString());
Console.WriteLine(item.ToString()); // option 1
return 0;
});
}
Console.WriteLine("Lambda run");
delegateInstance(); // the invocation list
Console.WriteLine("Lambda finish");
}
Import System.Runtime.Serialization.Formatters.Binary
<Serializable()>
Public Class MySerializableClass ' Define a Class which is able to be serialized '
Property s As String = "abcdedfg"
Property i As Integer = 50
Property f As Double = 3.14159256
End Class
Dim clientSend As TcpClient = New TcpClient() 'used to send stream'
Dim clientReceive As TcpClient = new TcpClient() 'used to receive stream'
Sub serializeAndSend()
Dim bf As BinaryFormatter = New BinaryFormatter()
bf.Serialize(clientSend.GetStream(), New MySerializableClass()) ' Serialize object and write into net-stream '
End Sub
Function receiveAndDeserialize() As Object
Dim bf As BinaryFormatter = New BinaryFormatter()
return bf.Deserialize(clientReceived.GetStream()) ' stream received and deserialize to object'
End Function