Tutorial by Examples: od

Suppose you have multiple threads running. Each thread is doing one task. You want to get notified either on the mainThread OR another thread, when all the task-threads are completed. The simplest solution to such a problem is a DispatchGroup. When using a DispatchGroup, for each request, you ente...

Validation attributes can be used to easily configure model validation. public class MyModel { public int id { get; set; } //sets the FirstName to be required, and no longer than 100 characters [Required] [StringLength(100)] public string FirstName { get; set; } } Th...

Xposed is a framework that allows you to hook method calls of other apps. When you do a modification by decompiling an APK, you can insert/change commands directly wherever you want. However, you will need to recompile/sign the APK afterwards and you can only distribute the whole package. With Xpose...

Create a new class implementing IXposedHookLoadPackage and implement the handleLoadPackage method: public class MultiPatcher implements IXposedHookLoadPackage { @Override public void handleLoadPackage(XC_LoadPackage.LoadPackageParam loadPackageParam) throws Throwable { ...

Considering a (post)model: public class User { public string FirstName { get; set; } public bool IsAdmin { get; set; } } With a view like so: @using (Html.BeginForm()) { @Html.EditorFor(model => model.FirstName) <input type="submit" value="Save" /...

The example in Visitor Pattern provides a compelling use-case for CRTP: struct IShape { virtual ~IShape() = default; virtual void accept(IShapeVisitor&) const = 0; }; struct Circle : IShape { // ... // Each shape has to implement this method the same way ...

System.IO.Compression.ZipFile.ExtractToDirectory("archive.zip", "myfolder") Extracts archive.zip to myfolder directory. In example paths are relative to program working directory. You can specify absolute paths.

scrollViewDidEndDecelerating: this tells the delegate that the scroll view has ended decelerating the scrolling movement. Objective C: - (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView { [self stoppedScrolling]; } - (void)scrollViewDidEndDragging:(UIScrollView *)scrollView w...

This example shows how to define a simple model in Sails.js You can generate an empty model file by typing sails generate model car You'll find the new file Car.js in api/models/. Next, you fill in some details. modules.exports = { tableName : 'cars', connection : 'mongodb', attr...

The UMD (Universal Module Definition) pattern is used when our module needs to be imported by a number of different module loaders (e.g. AMD, CommonJS). The pattern itself consists of two parts: An IIFE (Immediately-Invoked Function Expression) that checks for the module loader that is being i...

AMD is a module definition system that attempts to address some of the common issues with other systems like CommonJS and anonymous closures. AMD addresses these issues by: Registering the factory function by calling define(), instead of immediately executing it Passing dependencies as an array...

CommonJS is a popular modularization pattern that's used in Node.js. The CommonJS system is centered around a require() function that loads other modules and an exports property that lets modules export publicly accessible methods. Here's an example of CommonJS, we'll load Lodash and Node.js' fs m...

SELECT statement can be executed without FROM clause: declare @var int = 17; SELECT @var as c1, @var + 2 as c2, 'third' as c3 In this case, one row with values/results of expressions are returned.

This example shows a helper class that contains methods useful, when executing the queries for data. Every method here uses Java Generic's in order to be very flexible. public <T> List<T> selectElements(AbstractDao<T, ?> dao) { if (dao == null) { return null; } ...

In same cases different models could have same fields and same procedures in the product life cycle. To handle these similarities without having code repetition inheritance could be used. Instead of inheriting a whole class, mixin design pattern offers us to inherit (or some says include) some met...

To print a test field (TestField) from a test feature class (TestFC) in a test file geodatabase (Test.gdb) located in a temporary folder (C:\Temp): with arcpy.da.SearchCursor(r"C:\Temp\Test.gdb\TestFC",["TestField"]) as cursor: for row in cursor: print row[0]

The Scala Collections framework, according to its authors, is designed to be easy to use, concise, safe, fast, and universal. The framework is made up of Scala traits that are designed to be building blocks for creating collections. For more information on these building blocks, read the official S...

GetHashCode has major performance effects on Dictionary<> and HashTable. Good GetHashCode Methods should have an even distribution every integer should have a roughly equal chance of returning for a random instance if your method returns the same integer (e.g. the constant '999') for e...

var syntaxTree = CSharpSyntaxTree.ParseText( @"using System; using System.Collections; using System.Linq; using System.Text; namespace HelloWorldApplication { class Program { static void Main(string[] args) { Console.WriteLine(""Hello World""); } } }"); ...

Here are all access modifiers in venn diagrams, from more limiting to more accessible: Access ModifierDiagramprivateinternalprotectedprotected internalpublic Below you could find more information.