Tutorial by Examples: v

The Implement directive indicates that the web page, master page or user control page must implement the specified .Net framework interface. The basic syntax for implements directive is: <%@ Implements Interface="interface_name" %>

The Master directive specifies a page file as being the mater page. The basic syntax of sample MasterPage directive is: <%@ MasterPage Language="C#" AutoEventWireup="true" CodeFile="SiteMater.master.cs" Inherits="SiteMaster" %>

The Import directive imports a namespace into a web page, user control page of application. If the Import directive is specified in the global.asax file, then it is applied to the entire application. If it is in a page of user control page, then it is applied to that page or control. The basic synt...

The MasterType directive assigns a class name to the Master property of a page, to make it strongly typed. The basic syntax of MasterType directive is: <%@ MasterType attribute="value"[attribute="value" ...] %>

The Page directive defines the attributes specific to the page file for the page parser and the compiler. The basic syntax of Page directive is: <%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" Trace="tr...

The OutputCache directive controls the output caching policies of a web page or a user control. The basic syntax of OutputCache directive is: <%@ OutputCache Duration="15" VaryByParam="None" %>

This example show how you can check if a service already exists (i.e., is installed on the machine) or not. This code requires only the lowest privileges necessary, so each process can perform the check, no matter what level of security it is running at. #define UNICODE #define _UNICODE #include ...

IList<T> is never a subtype of a different IList<T1>. IList is invariant in its type parameter. class Animal { /* ... */ } class Dog : Animal { /* ... */ } IList<Dog> dogs = new List<Dog>(); IList<Animal> animals = dogs; // type error There is no subtype relat...

If you have a vsix file, you can install it by running the file. Get the vsix file (this is the extension installer) Run the file. In the window that opens, confirm the installation.

In Visual studio go to Tools > Extensions and updates... In the window that opens go to online Select Visual Studio Gallery You can search for an extension on the search box at the upper right corner Select the extension you want to add Click on download. Once download is complete, click...

int x = 5 / 0; // Undefined behavior Division by 0 is mathematically undefined, and as such it makes sense that this is undefined behavior. However: float x = 5.0f / 0.0f; // x is +infinity Most implementation implement IEEE-754, which defines floating point division by zero to return N...

int x = INT_MAX + 1; // x can be anything -> Undefined behavior If during the evaluation of an expression, the result is not mathematically defined or not in the range of representable values for its type, the behavior is undefined. (C++11 Standard paragraph 5/4) This is one of the mo...

Interfaces may have variant type parameters. interface IEnumerable<out T> { // ... } interface IComparer<in T> { // ... } but classes and structures may not class BadClass<in T1, out T2> // not allowed { } struct BadStruct<in T1, out T2> // not allo...

Delegates may have variant type parameters. delegate void Action<in T>(T t); // T is an input delegate T Func<out T>(); // T is an output delegate T2 Func<in T1, out T2>(); // T1 is an input, T2 is an output This follows from the Liskov Substitution Principle, w...

If you have a string that contains Python literals, such as strings, floats etc, you can use ast.literal_eval to evaluate its value instead of eval. This has the added feature of allowing only certain syntax. >>> import ast >>> code = """(1, 2, {'foo': 'bar'})&quot...

It is not possible to use eval or exec to execute code from untrusted user securely. Even ast.literal_eval is prone to crashes in the parser. It is sometimes possible to guard against malicious code execution, but it doesn't exclude the possibility of outright crashes in the parser or the tokenizer....

This will give current system version. Objective-C NSString *version = [[UIDevice currentDevice] systemVersion] Swift let version = UIDevice.currentDevice().systemVersion Swift 3 let version = UIDevice.current.systemVersion

<div class="navbar navbar-inverse navbar-fixed-top"> <div class="container"> <div class="navbar-header"> <!--- vvv Hamburger icon that gets shown when window reaches a certain scale vvv ---> <button type...

<div class="navbar navbar-inverse navbar-fixed-top"> <div class="container"> <div class="navbar-header"> <button type="button" class="navbar-toggle" data-toggle="collapse" data-target=".n...

<div class="navbar navbar-inverse navbar-fixed-top"> <div class="container"> <div class="navbar-header"> <button type="button" class="navbar-toggle" data-toggle="collapse" data-target=".n...