Sivaprasad S R

A new feature was introduced in c# 7.0, in which we can call a local methods to be defines and call within a method. This feature was not in the previous versions. Which is like, defining the call back function just above the method in jquery. The blow is as sample code static void Main(string[] args)   {     void Display(string str)     {       Console.WriteLine(str);   }        Display("Hello world....")     Console.ReadKey();   } 

Put the below code in xamarin.android (xamarin.droid) project. [assembly: ExportRenderer(typeof(NavigationPage), typeof(CustomNavigationRenderer))] namespace Example {     public class RootNavigationRenderer : NavigationRenderer     {         protected override void OnElementChanged(ElementChangedEventArgs e)         {             base.OnElementChanged(e);             RemoveAppIconFromActionBar();         }         void RemoveAppIconFromActionBar()         {             var actionBar = ((Activity)Context).ActionBar;             actionBar.SetIcon(new ColorDrawable(Color.Transparent.ToAndroid()));         }     } }

var Introduced in C# 3.0 At compile time, the compiler decide the type of variable which is declared.  Need to initialize at the time of deceleration. Visual Studio shows intellisense as the type of variable assigned is known to the compiler. We cannot assign two data type in one variable since the compiler has already assign the data type to the value.       that is : var obj1=1; obj1="hello";    will through an error. dynamic Introduced in C# 3.0 At runtime time, the compiler decide the type of variable which is declared.  No need to initialize at the time of deceleration. Visual Studio intellisense is not available since the type of variable assigned is unknown to the compiler, which will be known only at the run time. We can assign two data type in one variable since the compiler recreate the type when another data type is assigned to the variable.

The   is operator checks if an object can be cast to a specific type. if (someObject is StringBuilder) The as operator attempts to cast an object to a specific type, and returns null if it fails. StringBuilder b = someObject as StringBuilder;

Converting one type of data to another type it is also known as Type Casting.     Type Casting are of two types:           1) Implicit conversion                 int num = 2147483647;                 long bigNum = num;         2) Explicit conversion        double x = 1234.7;                int a;                // Cast double to int.                a = (int)x;

To set multiple startup projects In the Solution Explorer , select the solution. Right-click the node to get the context menu. Select Properties . The Solution Property Pages dialog box opens. Expand the Common Properties node, and click Startup Project . Click Multiple Startup Projects and set the appropriatet actions.

Step 1:  Get the NuGet package https://www.nuget.org/packages/Common.CheckComboBox/ Step 2: Add the CheckComboBox Control in the toolbar. Click here Step 3: Drag the "CheckedComboBox" control from the toolbar to the form to the position where it should be placed   Step 4: Add items to the CheckedComboBox control by        for (int i = 0; i < 10; i++)             {                 checkedComboBox1.Items.Add(i);             }