IT工程師數位筆記本

 1     void CreateTextBox()
 2     {
 3       var tb = new TextBox();
 4       tb.IsReadOnly = true;
 5       tb.Text = "Please wait ...";
 6       DoSomeStuff(() =>
 7       {
 8         tb.Text = string.Empty;
 9         tb.IsReadOnly = false;
10       });
11     }
12 
13     void DoSomeStuff(Action callback)
14     {
15       // Do some stuff - asynchronous would be helpful ...
16       callback();
17     }

 1     Func<string, string> SayMyName(string language)
 2     {
 3       switch (language.ToLower())
 4       {
 5         case "fr":
 6           return name =>
 7           {
 8             return "Je m'appelle " + name + ".";
 9           };
10         case "de":
11           return name =>
12           {
13             return "Mein Name ist " + name + ".";
14           };
15         default:
16           return name =>
17           {
18             return "My name is " + name + ".";
19           };
20       }
21     }
22 
23     void Main()
24     {
25       var lang = "de";
26       //Get language - e.g. by current OS settings
27       var smn = SayMyName(lang);
28       var name = Console.ReadLine();
29       var sentence = smn(name);
30       Console.WriteLine(sentence);
31     }

 1     static class Translations
 2     {
 3       static readonly Dictionary<string, Func<string, string>> smnFunctions 
 4         = new Dictionary<string, Func<string, string>>();
 5 
 6       static Translations()
 7       {
 8         smnFunctions.Add("fr", name => "Je m'appelle " + name + ".");
 9         smnFunctions.Add("de", name => "Mein Name ist " + name + ".");
10         smnFunctions.Add("en", name => "My name is " + name + ".");
11       }
12 
13       public static Func<string, string> GetSayMyName(string language)
14       {
15         //Check if the language is available has been omitted on purpose
16         return smnFunctions[language];
17       }
18     }
19 
20     // Now it is sufficient to call Translations.GetSayMyName("de") 
21     // to get the function with the German translation.

 1   class SomeClass
 2   {
 3       public Func<int> NextPrime
 4       {
 5           get;
 6           private set;
 7       }
 8 
 9       int prime;
10 
11       public SomeClass()
12       {
13       NextPrime = () =>
14       {
15         prime = 2;
16 
17         NextPrime = () =>
18         {
19           //Algorithm to determine next - starting at prime
20           //Set prime
21           return prime;
22         };
23 
24         return prime;
25       };
26       }
27   }

1       Action<int> loopBody = i => {
2           if(i == 1000)
3               loopBody = /* set to the body for the rest of the operations */;
4 
5           /* body for the first 1000 iterations */
6       };
7 
8       for(int j = 0; j < 10000000; j++)
9           loopBody(j);

1 (() => {
2     // Do Something here!
3 })();

1 ((string s, int no) => {
2     // Do Something here!
3 })("Example", 8);

1 await (async (string s, int no) => {
2     // Do Something here async using Tasks!
3 })("Example", 8);
4 
5 //Continue here after the task has been finished

 1       //Create anonymous object
 2       var person = new
 3       {
 4         Name = "Florian",
 5         Age = 28,
 6         Ask = (string question) =>
 7         {
 8           Console.WriteLine("The answer to `" + question + "` is certainly 42!");
 9         }
10       };
11 
12       //Execute function
13       person.Ask("Why are you doing this?");

1       var person = new
2       {
3         Name = "Florian",
4         Age = 28,
5         Ask = (Action<string>)((string question) =>
6         {
7           Console.WriteLine("The answer to `" + question + "` is certainly 42!");
8         })
9       };

 1       dynamic person = null;
 2       person = new
 3       {
 4         Name = "Florian",
 5         Age = 28,
 6         Ask = (Action<string>)((string question) =>
 7         {
 8           Console.WriteLine("The answer to `" + question + "` is certainly 42! My age is " + person.Age + ".");
 9         })
10       };
11 
12       //Execute function
13       person.Ask("Why are you doing this?");

 1     public Action AutoSave { get; private set; }
 2 
 3     public void ReadSettings(Settings settings)
 4     {
 5       /* Read some settings of the user */
 6 
 7       if (settings.EnableAutoSave)
 8         AutoSave = () => { /* Perform Auto Save */ };
 9       else
10         AutoSave = () => { }; //Just do nothing!
11     }

 1   class LazyLoad
 2   {
 3     public LazyLoad()
 4     {
 5       Search = query =>
 6       {
 7         var source = Database.SearchQuery(query);
 8 
 9         Search = subquery =>
10         {
11           var filtered = source.Filter(subquery);
12 
13           foreach (var result in filtered)
14             yield return result;
15         };
16 
17         foreach (var result in source)
18           yield return result;
19       };
20     }
21 
22     public Func<string, IEnumerable<ResultObject>> Search { get; private set; }
23   }

 1   class MyBaseClass
 2   {
 3     public Action SomeAction { get; protected set; }
 4 
 5     public MyBaseClass()
 6     {
 7       SomeAction = () =>
 8       {
 9         //Do something!
10       };
11     }
12   }

1   class MyInheritedClass : MyBaseClass
2   {
3       public MyInheritedClass
4       {
5           SomeAction = () => {
6               //Do something different!
7           };
8       }
9   }

 1   class MyBaseClass
 2   {
 3     public Action SomeAction { get; private set; }
 4 
 5     Stack<Action> previousActions;
 6 
 7     protected void AddSomeAction(Action newMethod)
 8     {
 9       previousActions.Push(SomeAction);
10       SomeAction = newMethod;
11     }
12 
13     protected void RemoveSomeAction()
14     {
15       if (previousActions.Count == 0)
16         return;
17 
18       SomeAction = previousActions.Pop();
19     }
20 
21     public MyBaseClass()
22     {
23       previousActions = new Stack<Action>();
24 
25       SomeAction = () =>
26       {
27         //Do something!
28       };
29     }
30   }

 1   void Main()
 2   {
 3       var mother = HotDaughter.Activator().Message;
 4       //mother = "I am the mother"
 5       var create = new HotDaughter();
 6       var daughter = HotDaughter.Activator().Message;
 7       //daughter = "I am the daughter"
 8   }
 9 
10   class CoolMother
11   {
12       public static Func<CoolMother> Activator { get; protected set; }
13     
14       //We are only doing this to avoid NULL references!
15       static CoolMother()
16       {
17           Activator = () => new CoolMother();
18       }
19 
20       public CoolMother()
21       {
22           //Message of every mother
23           Message = "I am the mother";
24       }
25     
26       public string Message { get; protected set; }
27   }
28 
29   class HotDaughter : CoolMother
30   {
31       public HotDaughter()
32       {
33           //Once this constructor has been "touched" we set the Activator ...
34           Activator = () => new HotDaughter();
35           //Message of every daughter
36           Message = "I am the daughter";
37       }
38   }

 1   public Action GetFinalizer(string input)
 2   {
 3       switch
 4       {
 5           case "random":
 6               return () => { /* ... */ };
 7           case "dynamic":
 8               return () => { /* ... */ };
 9           default:
10               return () => { /* ... */ };
11       }
12   }

 1   Dictionary<string, Action> finalizers;
 2 
 3   public void BuildFinalizers()
 4   {
 5       finalizers = new Dictionary<string, Action>();
 6       finalizers.Add("random", () => { /* ... */ });
 7       finalizers.Add("dynamic", () => { /* ... */ });
 8   } 
 9 
10   public Action GetFinalizer(string input)
11   {
12       if(finalizers.ContainsKey(input))
13           return finalizers[input];
14 
15       return () => { /* ... */ };
16   }

 1     static Dictionary<string, Action> finalizers;
 2 
 3     //The method should be called by a static constructor or something similar
 4     //The only requirement is that we built
 5     public static void BuildFinalizers()
 6     {
 7       finalizers = new Dictionary<string, Action>();
 8 
 9       //Get all types of the current (= where the code is contained) assembly
10       var types = Assembly.GetExecutingAssembly().GetTypes();
11 
12       foreach (var type in types)
13       {
14         //We check if the class is of a certain type
15         if (type.IsSubclassOf(typeof(MyMotherClass)))
16         {
17           //Get the constructor
18           var m = type.GetConstructor(Type.EmptyTypes);
19 
20           //If there is an empty constructor invoke it
21           if (m != null)
22           {
23             var instance = m.Invoke(null) as MyMotherClass;
24             //Apply the convention to get the name - in this case just we pretend it is as simple as
25             var name = type.Name.Remove("Mother");
26             //Name could be different, but let's just pretend the method is named MyMethod
27             var method = instance.MyMethod;
28 
29             finalizers.Add(name, method);
30           }
31         }
32       }
33     }
34 
35     public Action GetFinalizer(string input)
36     {
37       if (finalizers.ContainsKey(input))
38         return finalizers[input];
39 
40       return () => { /* ... */ };
41     }

 1     //The start is the same
 2 
 3     internal static void BuildInitialFinalizers()
 4     {
 5       finalizers = new Dictionary<string, Action>();
 6       LoadPlugin(Assembly.GetExecutingAssembly());
 7     }
 8 
 9     public static void LoadPlugin(Assembly assembly)
10     {
11       //This line has changed
12       var types = assembly.GetTypes();
13 
14       //The rest is identical! Perfectly refactored and obtained a new useful method
15       foreach (var type in types)
16       {
17         if (type.IsSubclassOf(typeof(MyMotherClass)))
18         {
19           var m = type.GetConstructor(Type.EmptyTypes);
20 
21           if (m != null)
22           {
23             var instance = m.Invoke(null) as MyMotherClass;
24             var name = type.Name.Remove("Mother");
25             var method = instance.MyMethod;
26             finalizers.Add(name, method);
27           }
28         }
29       }
30     }
31 
32     //The call is the same

1   class MyClass
2   {
3     public bool MyProperty
4     {
5       get;
6       set;
7     }
8   }

 1   class MyClass
 2   {
 3     [NumberToBooleanConverter]
 4     [StringToBooleanConverter]
 5     public bool MyProperty
 6     {
 7       get;
 8       set;
 9     }
10   }

 1   public class StringToBooleanConverterAttribute : ValueConverterAttribute
 2   {
 3       public StringToBooleanConverterAttribute()
 4           : base(typeof(string), v => {
 5               var str = (v as string ?? string.Empty).ToLower();
 6 
 7               if (str == "on")
 8                   return true;
 9               else if (str == "off")
10                   return false;
11 
12               throw new Exception("The only valid input arguments are [ on, off ]. You entered " + str + ".");
13           })
14       {
15           /* Nothing here on purpose */
16       }
17   }
18 
19   public abstract class ValueConverterAttribute : Attribute
20   {
21       public ValueConverterAttribute(Type expected, Func<object, object> converter)
22       {
23           Converter = converter;
24           Expected = expected;
25       }
26 
27       public ValueConverterAttribute(Type expected)
28       {
29           Expected = expected;
30       }
31 
32       public Func<Value, object> Converter { get; set; }
33 
34       public object Convert(object argument)
35       {
36           return Converter.Invoke(argument);
37       }
38 
39       public bool CanConvertFrom(object argument)
40       {
41           return Expected.IsInstanceOfType(argument);
42       }
43 
44       public Type Expected
45       {
46           get;
47           set;
48       }
49 
50       public string Type
51       {
52           get { return Expected.Name; }
53       }
54   }

1   struct FirstStruct
2   {
3     public SecondStruct Target;
4   }
5 
6   struct SecondStruct
7   {
8     public FirstStruct Source;
9   }

1   struct FirstStruct
2   {
3     public SecondStruct Target { get; set; }
4   }
5 
6   struct SecondStruct
7   {
8     public FirstStruct Source { get; set; }
9   }

1   struct FirstStruct
2   {
3     public SecondStruct? Target { get; set; }
4   }
5 
6   struct SecondStruct
7   {
8     public FirstStruct Source { get; set; }
9   }

 1   struct FirstStruct
 2   {
 3     readonly Func<SecondStruct> f;
 4 
 5     public FirstStruct(SecondStruct target)
 6     {
 7       f = () => target;
 8     }
 9 
10     public SecondStruct Target
11     {
12       get
13       {
14         return f();
15       }
16     }
17   }
18 
19   struct SecondStruct
20   {
21     public FirstStruct Source { get; set; }
22   }