Tutorial by Examples: l

Background TypeScript is a typed superset of JavaScript that compiles directly to JavaScript code. TypeScript files commonly use the .ts extension. Many IDEs support TypeScript without any other setup required, but TypeScript can also be compiled with the TypeScript Node.JS package from the command...

Anonymous type equality is given by the Equals instance method. Two objects are equal if they have the same type and equal values (through a.Prop.Equals(b.Prop)) for every property. var anon = new { Foo = 1, Bar = 2 }; var anon2 = new { Foo = 1, Bar = 2 }; var anon3 = new { Foo = 5, Bar = 10 }; ...

Arrays of anonymous types may be created with implicit typing. var arr = new[] { new { Id = 0 }, new { Id = 1 } };

A view can filter some rows from the base table or project only some columns from it: CREATE VIEW new_employees_details AS SELECT E.id, Fname, Salary, Hire_date FROM Employees E WHERE hire_date > date '2015-01-01'; If you select form the view: select * from new_employees_details IdFNam...

A view can be a really complex query(aggregations, joins, subqueries, etc). Just be sure you add column names for everything you select: Create VIEW dept_income AS SELECT d.Name as DepartmentName, sum(e.salary) as TotalSalary FROM Employees e JOIN Departments d on e.DepartmentId = d.id GROUP BY...

What is Serialization Serialization is the process of converting an object's state (including its references) to a sequence of bytes, as well as the process of rebuilding those bytes into a live object at some future time. Serialization is used when you want to persist the object. It is also used b...

Installing Visual Studio If you do not have Visual Studio installed, you can download the free Visual Studio Community Edition here. If you already have it installed, you can proceed to the next step. Creating an ASP.NET Core MVC Application. Open Visual Studio. Select File > New Project. ...

By default, all the methods declared in a protocol are required. This means that any class that conforms to this protocol must implement those methods. It is also possible to declare optional methods. These method can be implemented only if needed. You mark optional methods with the @optional dire...

The following syntax indicate that a class adopts a protocol, using angle brackets. @interface NewClass : NSObject <NewProtocol> ... @end This means that any instance of NewClass will respond to methods declared in its interface but also it will provide an implementation for all the requ...

If you screw up a rebase, one option to start again is to go back to the commit (pre rebase). You can do this using reflog (which has the history of everything you've done for the last 90 days - this can be configured): $ git reflog 4a5cbb3 HEAD@{0}: rebase finished: returning to refs/heads/foo 4...

The typeof operator works on type parameters. class NameGetter<T> { public string GetTypeName() { return typeof(T).Name; } }

toList flattens a Foldable structure t a into a list of as. ghci> toList [7, 2, 9] -- t ~ [] [7, 2, 9] ghci> toList (Right 'a') -- t ~ Either e "a" ghci> toList (Left "foo") -- t ~ Either String [] ghci> toList (3, True) -- t ~ (,) Int [True] toList is ...

Mark your UIView subclass as an accessible element so that it is visible to VoiceOver. myView.isAccessibilityElement = YES; Ensure that the view speaks a meaningful label, value, and hint. Apple provides more details on how to choose good descriptions in the Accessibility Programming Guide.

The accessibility frame is used by VoiceOver for hit testing touches, drawing the VoiceOver cursor, and calculating where in the focused element to simulate a tap when the user double-taps the screen. Note that the frame is in screen coordinates! myElement.accessibilityFrame = frameInScreenCoordina...

In many cases, content within a single screen will update with new or different content. For example, imagine a form that reveals additional options based on the user’s answer to a previous question. In this case, a “layout change” notification lets you either announce the change or focus on a new e...

VoiceOver navigates from top-left to bottom-right, irrespective of the view hierarchy. This is usually how content is arranged in left-to-right languages since sighted individuals tend to scan the screen in an “F-shaped pattern”. VoiceOver users will expect to navigate the same way as typical users....

VoiceOver can navigate many apps on iOS because most UIKit classes implement UIAccessibilityProtocol. Features that don’t represent onscreen elements using UIView, including apps that leverage Core Graphics or Metal to perform drawing, must describe these elements for accessibility. As of iOS 8.0, t...

Modal views completely capture the user’s attention until a task is complete. iOS clarifies this to users by dimming and disabling all other content when a modal view, such as an alert or popover, is visible. An app that implements a custom modal interface needs to hint to VoiceOver that this view d...

Most UIKit classes, including UIView, adhere to UIAccessibilityProtocol and return correct values by default. It’s easy to take for granted that a UIView set to hidden is also absent from the accessibility hierarchy and won’t be navigated by VoiceOver. While this default behavior is usually sufficie...

1.8 You can remove a submodule (e.g. the_submodule) by calling: $ git submodule deinit the_submodule $ git rm the_submodule git submodule deinit the_submodule deletes the_submodules' entry from .git/config. This excludes the_submodule from git submodule update, git submodule sync and git ...