Tutorial by Examples: am

You can also query dynamically if you leave off the generic type. IDBConnection db = /* ... */; IEnumerable<dynamic> result = db.Query("SELECT 1 as A, 2 as B"); var first = result.First(); int a = (int)first.A; // 1 int b = (int)first.B; // 2

To fetch multiple grids in a single query, the QueryMultiple method is used. This then allows you to retrieve each grid sequentially through successive calls against the GridReader returned. var sql = @"select * from Customers where CustomerId = @id select * from Orders where Cust...

Dapper makes it easy to follow best practice by way of fully parameterized SQL. Parameters are important, so dapper makes it easy to get it right. You just express your parameters in the normal way for your RDBMS (usually @foo, ?foo or :foo) and give dapper an object that has a member called foo...

string fullOrRelativePath = "testfile.txt"; string fileData; using (var reader = new StreamReader(fullOrRelativePath)) { fileData = reader.ReadToEnd(); } Note that this StreamReader constructor overload does some auto encoding detection, which may or may not conform to the ...

The nameof operator returns the name of a code element as a string. This is useful when throwing exceptions related to method arguments and also when implementing INotifyPropertyChanged. public string SayHello(string greeted) { if (greeted == null) throw new ArgumentNullException(nam...

Declaration: class MyGenericClass<T1, T2, T3, ...> { // Do something with the type parameters. } Initialisation: var x = new MyGenericClass<int, char, bool>(); Usage (as the type of a parameter): void AnotherMethod(MyGenericClass<float, byte, char> arg) { ... } ...

Declaration: void MyGenericMethod<T1, T2, T3>(T1 a, T2 b, T3 c) { // Do something with the type parameters. } Invocation: There is no need to supply type arguements to a genric method, because the compiler can implicitly infer the type. int x =10; int y =20; string z = "tes...

Declaration: interface IMyGenericInterface<T1, T2, T3, ...> { ... } Usage (in inheritance): class ClassA<T1, T2, T3> : IMyGenericInterface<T1, T2, T3> { ... } class ClassB<T1, T2> : IMyGenericInterface<T1, T2, int> { ... } class ClassC<T1> : IMyGenericI...

Get Instance method and invoke it using System; public class Program { public static void Main() { var theString = "hello"; var method = theString .GetType() .GetMethod("Substring", ...

<Foo> <Dog/> </Foo> public class Foo { // Using XmlElement [XmlElement(Name="Dog")] public Animal Cat { get; set; } }

<Store> <Articles> <Product/> <Product/> </Articles> </Store> public class Store { [XmlArray("Articles")] public List<Product> Products {get; set; } }

The namespace keyword is an organization construct that helps us understand how a codebase is arranged. Namespaces in C# are virtual spaces rather than being in a physical folder. namespace StackOverflow { namespace Documentation { namespace CSharp.Keywords { ...

using System; using System.IO; using System.Net; using System.Net.Sockets; using System.Text; class TcpChat { static void Main(string[] args) { if(args.Length == 0) { Console.WriteLine("Basic TCP chat"); Console.WriteLine(); ...

List<int> l2 = l1.FindAll(x => x > 6); Here x => x > 6 is a lambda expression acting as a predicate that makes sure that only elements above 6 are returned.

public delegate int ModifyInt(int input); ModifyInt multiplyByTwo = x => x * 2; The above Lambda expression syntax is equivalent to the following verbose code: public delegate int ModifyInt(int input); ModifyInt multiplyByTwo = delegate(int x){ return x * 2; };

using System.Text; //allows you to access classes within this namespace such as StringBuilder //without prefixing them with the namespace. i.e: //... var sb = new StringBuilder(); //instead of var sb = new System.Text.StringBuilder();

using st = System.Text; //allows you to access classes within this namespace such as StringBuilder //prefixing them with only the defined alias and not the full namespace. i.e: //... var sb = new st.StringBuilder(); //instead of var sb = new System.Text.StringBuilder();

Every method has a unique signature consisting of a accessor (public, private, ...) ,optional modifier (abstract), a name and if needed method parameters. Note, that the return type is not part of the signature. A method prototype looks like the following: AccessModifier OptionalModifier ReturnTyp...

Calling a static method: // Single argument System.Console.WriteLine("Hello World"); // Multiple arguments string name = "User"; System.Console.WriteLine("Hello, {0}!", name); Calling a static method and storing its return value: string input = System.Con...

A method can declare any number of parameters (in this example, i, s and o are the parameters): static void DoSomething(int i, string s, object o) { Console.WriteLine(String.Format("i={0}, s={1}, o={2}", i, s, o)); } Parameters can be used to pass values into a method, so that th...