Csharp Articles - Page 134 of 258

Use the isFixedSize property of Hashtable class to get a value indicating whether the Hashtable has a fixed size.The following is an example showing how to work with IsFixedSize property.Example Live Demousing System; using System.Collections; namespace Demo {    class Program {       static void Main(string[] args) {          Hashtable ht = new Hashtable();          ht.Add("D01", "Finance");          ht.Add("D02", "HR");          ht.Add("D03", "Operations");          Console.WriteLine("IsFixedSize = " + ht.IsFixedSize);          Console.ReadKey();       }    } }OutputIsFixedSize = FalseAbove we ... Read More

Use the File.exists method in C# to check if a file exits in C# or not.Firstly, check whether the file is present in the current directory.if (File.Exists("MyFile.txt")) {    Console.WriteLine("The file exists."); }After that check whether the file exist in a directory or not.if (File.Exists(@"D:\myfile.txt")) {    Console.WriteLine("The file exists."); }Let us see the complete example to check if a file exists in C#.Example Live Demousing System; using System.IO; class Demo {    static void Main() {       if (File.Exists("MyFile.txt")) {          Console.WriteLine("File exists...");       } else {          Console.WriteLine("File does ... Read More

To retrieve the attributes of a file, use the FileAttributes Eumeration. It has various members like compressed, directory, hidden, etc. To check if a file is hidden, use the hidden member name. If the FileAttributes.hidden is set that would mean the file is hidden. Firstly, get the path to find the attributes. FileAttributes attributes = File.GetAttributes(path); If the following is set, that would mean the file is now hidden using the hidden member name. File.SetAttributes(path, File.GetAttributes(path) | FileAttributes.Hidden); Console.WriteLine("The {0} file is hidden.", path);

Use the IsReadOnly property to get a value indicating whether the SortedList is read-only or not.You can try to run the following code to implement IsReadOnly property in C#.Here, we have set the SortedList first.SortedList s = new SortedList();Added elements.s.Add("S001", "Jack"); s.Add("S002", "Henry");Now check for IsReadOnly.Console.WriteLine("IsReadOnly = " + s.IsReadOnly);The following is the complete code.Example Live Demousing System; using System.Collections; namespace Demo {    class Program {       static void Main(string[] args) {          SortedList s = new SortedList();          s.Add("S001", "Jack");          s.Add("S002", "Henry");          Console.WriteLine("IsReadOnly ... Read More

Character constantsCharacter literals are enclosed in single quotes. For example, 'x' and can be stored in a simple variable of char type. A character literal can be a plain character (such as 'x'), an escape sequence (such as '\t'), or a universal character (such as '\u02C0').Certain characters in C# are preceded by a backslash. They have special meaning and they are used to represent like newline () or tab (\t).Example Live Demousing System; namespace Demo {    class MyApplication {       static void Main(string[] args) {          Console.WriteLine("Welcome\t to the website");          Console.ReadLine(); ... Read More

C# has many operators that work on the left-right and righ-left associativity. Chanining depends on the left-to-right associativity on operators with same precedence. Operator precedence determines the grouping of terms in an expression. This affects evaluation of an expression. Certain operators have higher precedence than others do; for example, the multiplication operator has higher precedence than the addition operator. The operators with the highest precedence appear at the top of the table, those with the lowest appear at the bottom. Within an expression, higher precedence operators are evaluated first. To check whether a string is null or not, you can ... Read More

To draw an ellipse, use the drawEllipse() method in C# that belong to the Graphics object. It has a pen object as well as a rectangle object. You need windows form to draw shapes in C#. Set graphics object. Graphics g = this.CreateGraphics(); Now, the pen object. Pen p = new Pen(new SolidBrush(Color.Red), 15); The following is the rectangle object. Rectangle r = new Rectangle(120, 60, 180, 180); Now use the drawEllipse() method with the graphics object and add both the objects in it to draw an ellipse. s.DrawEllipse(p, r);

Use the IsFixedSize property in C# to get a value indicating whether the SortedList has a fixed size.The following is an example showing SorteList with the usage of IsFixedSize property.Example Live Demousing System; using System.Collections; namespace Demo {    class Program {       static void Main(string[] args) {          SortedList s = new SortedList();          s.Add("S1", "Maths");          s.Add("S2", "Science");          s.Add("S3", "English");          s.Add("S4", "Economics");          Console.WriteLine("IsFixedSize = " + s.IsFixedSize);       }    } }OutputIsFixedSize = FalseWe ... Read More

Using the DateTime nullable type, you can assign the null literal to the DateTime type.A nullable DateTime is specified using the following question mark syntax.DateTime?The following is the code to implement Nullable Datetime.Example Live Demousing System; class Program {    static void Main() {       DateTime? dt = null;       DateFunc(dt);       dt = DateTime.Now;       DateFunc(dt);       dt = null;       Console.WriteLine(dt.GetValueOrDefault());    }    static void DateFunc(DateTime? dt) {       if (dt.HasValue) {          Console.WriteLine(dt.Value);       } else {          Console.WriteLine(0);       }    } }Output0 9/17/2018 8:27:07 AM 1/1/0001 12:00:00 AM

A class can be derived from more than one class or interface, which means that it can inherit data and functions from multiple base classes or interfaces.The derived class inherits the base class member variables and member methods. Therefore, the super class object should be created before the subclass is created. You can give instructions for superclass initialization in the member initialization list.Here you can see object is created for the inherited class.Example Live Demousing System; namespace Demo {    class Rectangle {       protected double length;       protected double width;       public Rectangle(double l, ... Read More