create 2d barcode vb.net // Use dot-syntax notation // Use dot-syntax notation in C#

Create Data Matrix ECC200 in C# // Use dot-syntax notation // Use dot-syntax notation

// Use dot-syntax notation // Use dot-syntax notation
Making Data Matrix ECC200 In C#
Using Barcode drawer for Visual Studio .NET Control to generate, create Data Matrix image in VS .NET applications.
www.OnBarcode.com
Recognizing Data Matrix In C#.NET
Using Barcode scanner for .NET Control to read, scan read, scan image in .NET applications.
www.OnBarcode.com
This code produces the following output:
Barcode Creator In Visual C#
Using Barcode creator for Visual Studio .NET Control to generate, create Barcode image in .NET applications.
www.OnBarcode.com
Create QR Code 2d Barcode In Visual C#
Using Barcode maker for Visual Studio .NET Control to generate, create QR-Code image in .NET applications.
www.OnBarcode.com
Value of A: 10
2D Barcode Creation In Visual C#
Using Barcode generation for Visual Studio .NET Control to generate, create Matrix Barcode image in VS .NET applications.
www.OnBarcode.com
Code 128 Code Set A Creation In C#
Using Barcode creation for VS .NET Control to generate, create USS Code 128 image in .NET framework applications.
www.OnBarcode.com
Figure 6-5. Static methods of a class can be called even if there are no instances of the class.
Paint Linear 1D Barcode In Visual C#.NET
Using Barcode maker for Visual Studio .NET Control to generate, create Linear 1D Barcode image in Visual Studio .NET applications.
www.OnBarcode.com
Generate ISBN - 13 In C#
Using Barcode drawer for VS .NET Control to generate, create International Standard Book Number image in Visual Studio .NET applications.
www.OnBarcode.com
CHAPTER 6 MORE ABOUT CLASSES
Create ECC200 In C#
Using Barcode generator for .NET Control to generate, create Data Matrix image in .NET applications.
www.OnBarcode.com
Data Matrix 2d Barcode Printer In None
Using Barcode maker for Office Excel Control to generate, create Data Matrix 2d barcode image in Excel applications.
www.OnBarcode.com
Other Static Class Member Types
Create DataMatrix In Java
Using Barcode creation for Java Control to generate, create ECC200 image in Java applications.
www.OnBarcode.com
EAN 13 Creation In Visual Studio .NET
Using Barcode printer for Reporting Service Control to generate, create EAN / UCC - 13 image in Reporting Service applications.
www.OnBarcode.com
The types of class members that can be declared static are shown checked in Table 6-2. The other member types cannot be declared static. Table 6-2. Class Member Types That Can Be Declared Static
Drawing Data Matrix ECC200 In None
Using Barcode printer for Office Word Control to generate, create Data Matrix image in Office Word applications.
www.OnBarcode.com
GS1-128 Creator In Objective-C
Using Barcode drawer for iPhone Control to generate, create EAN 128 image in iPhone applications.
www.OnBarcode.com
Data Members (Store Data)
Data Matrix ECC200 Maker In Visual Studio .NET
Using Barcode maker for ASP.NET Control to generate, create Data Matrix image in ASP.NET applications.
www.OnBarcode.com
UPC Symbol Creator In None
Using Barcode generator for Software Control to generate, create UPC Symbol image in Software applications.
www.OnBarcode.com
Fields Constants
Generating PDF417 In None
Using Barcode maker for Online Control to generate, create PDF-417 2d barcode image in Online applications.
www.OnBarcode.com
Barcode Drawer In Objective-C
Using Barcode creation for iPad Control to generate, create Barcode image in iPad applications.
www.OnBarcode.com
Function Members (Execute Code)
Create QR Code In Java
Using Barcode creator for Java Control to generate, create QR Code image in Java applications.
www.OnBarcode.com
GS1 - 12 Drawer In None
Using Barcode maker for Office Excel Control to generate, create GTIN - 12 image in Office Excel applications.
www.OnBarcode.com
Methods Properties Constructors Operators Indexers Events
Note Unlike C and C++, in C# there are no global constants. Every constant must be declared within a type.
CHAPTER 6 MORE ABOUT CLASSES
Member Constants
Member constants are like the local constants covered in the previous chapter, except that they are declared in the class declaration, as in the following example: class MyClass { const int IntVal = 100; } Type Initializer const double PI = 3.1416;
// Defines a constant of type int // with a value of 100.
// Error: cannot be declared outside a type // declaration
Like local constants, the value used to initialize a member constant must be computable at compile time, and is usually one of the predefined simple types or an expression composed of them. class MyClass { const int IntVal1 = 100; const int IntVal2 = 2 * IntVal1; }
// Fine, since the value of IntVal1 // was set in the previous line.
Like local constants, you cannot assign to a member constant after its declaration. class MyClass { const int IntVal; IntVal = 100; }
// Error: initialization is required. // Error: assignment is not allowed.
CHAPTER 6 MORE ABOUT CLASSES
Constants Are Like Statics
Member constants, however, are more interesting than local constants; they act like static values. They are visible to every instance of the class, and they are available even if there are no instances of the class. For example, the following code declares class X with constant field PI. Main does not create any instances of X, and yet it can use field PI and print its value. class X { public const double PI = 3.1416; } class Program { static void Main() { Console.WriteLine("pi = {0}", X.PI); } } This code produces the following output:
// Use static field PI
pi = 3.1416
CHAPTER 6 MORE ABOUT CLASSES
Unlike actual statics, however, constants do not have their own storage locations, and are substituted in by the compiler at compile time in a manner similar to #define values in C and C++. This is shown in Figure 6-6, which illustrates the preceding code. Hence, although a constant member acts like a static, you cannot declare a constant as static. static const double PI = 3.14; Error: can't declare a constant as static
Figure 6-6. Constant fields act like static fields, but do not have a storage location in memory.
CHAPTER 6 MORE ABOUT CLASSES
Properties
A property is a member that represents an item of data in a class instance or class. Using a property appears very much like writing to, or reading from, a field. The syntax is the same. For example, the following code shows the use of a class called MyClass that has both a public field and a public property. From their usage, you cannot tell them apart. MyClass mc = new MyClass(); mc.MyField = 5; mc.MyProperty = 10; // Assigning to a field // Assigning to a property
WriteLine("{0} {1}", mc.MyField, mc.MyProperty); // Read field and property A property, like a field, has the following characteristics: It is a named class member. It has a type. It can be assigned to and read from. Unlike a field, however, a property is a function member. It does not allocate memory for data storage! It executes code. A property is a named set of two matching methods called accessors. The set accessor is used for assigning a value to the property. The get accessor is used for retrieving a value from the property. Figure 6-7 shows the representation of a property. The code on the left shows the syntax of declaring a property named MyValue, of type int. The image on the right shows how properties will be displayed visually in this text. Notice that the accessors are shown sticking out the back, because, as you will soon see, they are not directly callable.
Figure 6-7. An example property of type int, named MyValue
CHAPTER 6 MORE ABOUT CLASSES
Property Declarations and Accessors
The set and get accessors have predefined syntax and semantics. You can think of the set accessor as a method with a single parameter that sets the value of the property. The get accessor has no parameters and returns a value from the property. The set accessor always has the following: A single, implicit value parameter named value, of the same type as the property A return type of void The get accessor always has the following: No parameters A return type of the same type as the property The structure of a property declaration is shown in Figure 6-8. Notice in the figure that neither accessor declaration has explicit parameter or return type declarations. They don t need them, because they are implicit in the type of the property.
Figure 6-8. The syntax and structure of a property declaration The implicit parameter value in the set accessor is a normal value parameter. Like other value parameters, you can use it to send data into a method body or in this case, the accessor block. Once inside the block, you can use value like a normal variable, including assigning values to it. Other important points about accessors are the following: All paths through the implementation of a get accessor must include a return statement that returns a value of the property type. The set and get accessors can be declared in either order, and no methods other than the two accessors are allowed on a property.
Copyright © OnBarcode.com . All rights reserved.