Tutorial by Examples: l

Okay it took me about a day to figure it out so here I am posting the steps I followed to get my Database First working in a Class Project (.NET Core), with a .NET Core Web App. Step 1 - Install .NET Core Make Sure you are using .NET Core not DNX (Hint: You should be able to see the .NET Core opti...

A daemon process executes a program in the background, usually without user interaction. The example below shows how to create a daemon and register a listener, which monitors all open applications. The main part is the function call NSRunLoop.mainRunLoop().run(), which starts the daemon. class MyO...

This serializer has some nice features that the default .net json serializer doesn't have, like Null value handling, you just need to create the JsonSerializerSettings : public static string Serialize(T obj) { string result = JsonConvert.SerializeObject(obj, new JsonSerializerSettings { NullVa...

You can make a URI parameter optional by adding a question mark to the route parameter. You can also specify a default value by using the form parameter=value. public class BooksController : Controller { // eg: /books // eg: /books/1430210079 [Route(“books/{isbn?}”)] public Act...

You can also apply the [Route] attribute on the controller level, capturing the action as a parameter. That route would then be applied on all actions in the controller, unless a specific [Route] has been defined on a specific action, overriding the default set on the controller. [RoutePrefix(“prom...

Pretext This is an introduction to the Hello World program example on the Raspberry Pi written in C. The following example makes use of the command line interface and is set up as a step-by-step guide. Along with creating a Hello World program, the reader will be introduced to simple linux comman...

Sending data back to the parent, to do this we simply pass a function as a prop from the parent component to the child component, and the child component calls that function. In this example, we will change the Parent state by passing a function to the Child component and invoking that function ins...

In the opening section of a bash script, it's possible to define some variables that function as helpers to color or otherwise format the terminal output during the run of the script. Different platforms use different character sequences to express color. However, there's a utility called tput whic...

Logs are very important. Recreate an error context can be sometimes very painful due to the lack of information about how and when the error occurred. This example shows: How to add user's data in the error logs How to add post parameters sent when an error occurred How to use WebPr...

Java Code import org.opencv.core.Mat; import org.opencv.core.MatOfRect; import org.opencv.core.Point; import org.opencv.core.Rect; import org.opencv.core.Scalar; import org.opencv.highgui.Highgui; import org.opencv.highgui.VideoCapture; import org.opencv.objdetect.CascadeClassifier; publ...

Use Nuget to install the Nancy and Nancy.Hosting.Self packages into the project. Instantiate a new NancyHost object and pass in the relevant URL using( var host = new NancyHost( hostConfiguration, new Uri( "http://localhost:1234" ) ) ) { host.Start(); Console.WriteLine( "Running o...

_refreshControl(){ return ( <RefreshControl refreshing={this.state.refreshing} onRefresh={()=>this._refreshListView()} /> ) } refreshing: is the state of the spinner (true, false). onRefresh: this function will invoke when refresh the ListView/Scr...

_refreshListView(){ //Start Rendering Spinner this.setState({refreshing:true}) this.state.cars.push( {name:'Fusion',color:'Black'}, {name:'Yaris',color:'Blue'} ) //Updating the dataSource with new data this.setState({ dataSource: this.state.data...

RefreshControl is used inside a ScrollView or ListView to add pull to refresh functionality. at this example we will use it with ListView 'use strict' import React, { Component } from 'react'; import { StyleSheet, View, ListView, RefreshControl, Text } from 'react-native' class RefreshContr...

You can quickly determine if a text includes a specific pattern using Regex. There are multiple ways to work with Regex in PowerShell. #Sample text $text = @" This is (a) sample text, this is a (sample text) "@ #Sample pattern: Content wrapped in () $pattern = '\(.*?\)' Using ...

A common task for regex is to replace text that matches a pattern with a new value. #Sample text $text = @" This is (a) sample text, this is a (sample text) "@ #Sample pattern: Text wrapped in () $pattern = '\(.*?\)' #Replace matches with: $newvalue = 'test' Using -Replace...

Sometimes you need to replace a value matching a pattern with a new value that's based on that specific match, making it impossible to predict the new value. For these types of scenarios, a MatchEvaluator can be very useful. In PowerShell, a MatchEvaluator is as simple as a scriptblock with a singl...

A regex-pattern uses many special characters to describe a pattern. Ex., . means "any character", + is "one or more" etc. To use these characters, as a .,+ etc., in a pattern, you need to escape them to remove their special meaning. This is done by using the escape character whi...

There are multiple ways to find all matches for a pattern in a text. #Sample text $text = @" This is (a) sample text, this is a (sample text) "@ #Sample pattern: Content wrapped in () $pattern = '\(.*?\)' Using Select-String You can find all matches (global match) by adding t...

You can delete existing snapshots of database using DELETE DATABASE statement: DROP DATABASE Mydatabase_morning In this statement you should reference name of the database snapshot.