Essential Books

Non-Standard Event Declaration

suggest change

Events can be of any delegate type, not just EventHandler and EventHandler<T>. For example: 

//Declaring an event
public event Action<Param1Type, Param2Type, ...> EventName;

This is used similarly to standard EventHandler events: 

//Adding a named event handler
public void HandlerName(Param1Type parameter1, Param2Type parameter2, ...) {
    /* Handler logic */
}
EventName += HandlerName;

//Adding an anonymous event handler
EventName += (parameter1, parameter2, ...) => { /* Handler Logic */ };

//Invoking the event
EventName(parameter1, parameter2, ...);

It is possible to declare multiple events of the same type in a single statement, similar to with fields and local variables (though this may often be a bad idea): 

public event EventHandler Event1, Event2, Event3;

This declares three separate events (Event1, Event2, and Event3) all of type EventHandler.

Note: Although some compilers may accept this syntax in interfaces as well as classes, the C# specification (v5.0 ยง13.2.3) provides grammar for interfaces that does not allow it, so using this in interfaces may be unreliable with different compilers.

Found a mistake? Have a question or improvement idea? Let me know.

Feedback about page:

Feedback:
Optional: your email if you want me to get back to you:

Events:
* Events
* Declaring and Raising Events
* Creating cancelable event
* Event Properties
* Standard Event Declaration
* Anonymous Event Handler Declaration
* Non-Standard Event Declaration
* Creating custom EventArgs containing additional data
Table Of Contents
0 Getting Started With C#
1 Literals
2 Operators
3 Conditional Statements
4 Equality Operator
5 Equals and GetHashCode
6 Null-Coalescing Operator
7 Null-Conditional Operators
8 nameof Operator
9 Verbatim String
10 Common String Operations
11 String Format
12 String Concatenate
13 String Manipulation
14 String Interpolation
15 String Escape Sequences
16 StringBuilder
17 Regex
18 DateTime
19 Arrays
20 On Algorithm for circular rotation of an array
21 Enum
22 Tuples
23 Overview of C# collections
24 GUID
25 BigInteger
26 Collection Initializers
27 Looping
28 Iterators
29 IEnumerable
30 Value type vs Reference type
31 Built-in Types
32 Aliases of built-in types
33 Anonymous types
34 Dynamic type
35 Type Conversion
36 Casting
37 Nullable types
38 Constructors and Finalizers
39 Access Modifiers
40 Interfaces
41 Static Classes
42 Singleton Implementation
43 Dependency Injection
44 Partial class and methods
45 Object Initializers
46 Methods
47 Extension Methods
48 Named Arguments
49 Named And Optional Arguments
50 Data Annotation
51 Keywords
52 Recursion
53 Naming Conventions
54 XML Documentation Comments
55 Comments and regions
56 Inheritance
57 Generics
58 Using Statement
59 Using Directive
60 IDisposable interface
61 Reflection
62 IQueryable interface
63 LINQ to Objects
64 LINQ Queries
65 LINQ to XML
66 Parallel LINQ PLINQ
67 XmlDocument
68 XDocument
69 C# 7.0 Features
70 C# 6.0 Features
71 C# 5.0 Features
72 C# 4.0 Features
73 C# 3.0 Features
74 Exception Handling
75 NullReferenceException
76 Handling FormatException
77 Read and Understand Stack trackes
78 Diagnostics
79 Overflow
80 JSON handling
81 Using json.net
82 Lambda Expressions
83 Lambda expressions
84 Generic Lambda Query Builder
85 Properties
86 Initializing Properties
87 INotifyPropertyChanged interface
88 Events
89 Expression Trees
90 Overload Resolution
91 Preprocessor directives
92 Structs
93 Attributes
94 Delegates
95 File and Stream IO
96 Networking
97 Performing HTTP requests
98 Reading and writing .zip files
99 FileSystemWatcher
100 Asynchronous Socket
101 Action Filters
102 Polymorphism
103 Immutability
104 Indexer
105 Checked and Unchecked
106 Stream
107 Timers
108 Stopwatches
109 Threading
110 Async/Await, BackgroundWorker, Task and Thread examples
111 Async Await
112 Synchronization Context in Async/Await
113 BackgroundWorker
114 Task Parallel Library
115 Making a variable thread safe
116 Lock Statement
117 Yield Keyword
118 Task Parallel Library TPL Dataflow Constructs
119 Functional Programming
120 Func delegates
121 Function with multiple return values
122 Binary Serialization
123 ICloneable
124 IComparable
125 Accessing Databases
126 Using SQLite
127 Caching
128 Code Contracts
129 Code Contracts and Assertions
130 Structural Design Patterns
131 Creational Design Patterns
132 Implementing Decorating Design Pattern
133 Implementing Flyweight Design Pattern
134 System.Management.Automation
135 Pointers
136 Pointers and Unsafe Code
137 Simulating C Unions with C# Structs
138 Reactive Extensions Rx
139 AsseblyInfo.cs examples
140 Creating Console Application
141 CLSCompliantAttribute
142 ObservableCollection
143 Hash Functions
144 Generating Random Numbers
145 Cryptography
146 Unsafe Code in .NET
147 C# Script
148 Runtime Compile
149 Interoperability
150 .NET Compiler Platform Roslyn
151 Creating Own MessageBox in Windows Form Application
152 Including Font Resources
153 Garbage Collector
154 Windows Communication Foundation
155 Contributors