Sunwen Tutorial----C # Advanced (vii)

To say is the structure (struct) in C #, note that the structure I'm talking about here is not referring to the language structure of C #. Here is a kind of thing that is relative to the class, and I'm going to say this struct relative to the class.

The following example illustrates how to create a structure with properties, methods, and a field. And how to use him.

From://Structs\struct1.cs
001:using System;
002:struct simplestruct
003: {
004:private int xval;
005:public int X
006: {
007:get {
008:return Xval;
009:}
010:set {
011:if (Value < 100)
012:xval = value;
013:}
014:}
015:public void Displayx ()
016: {
017:console.writeline ("The stored value is: {0}", xval);
018:}
019:}
020:
021:class TestClass
022: {
023:public static void Main ()
024: {
025:simplestruct ss = new Simplestruct ();
026:ss. X = 5;
027:ss. Displayx ();
028:}
029:}

The output of this example is:

The stored value is:5
From the above example, we can see that the structure and the class seem to be the same. Indeed, if you use the class to re-write the program, the result is the same. But, obviously, two of the same things are impossible to come together. A struct is a value type, and a class is a reference type. So you can build objects like built-in types with structs.

Also, if you use a new keyword to create an instance of a class, it is allocated as a heap (heap), and when you use new to create an instance of a struct, it is allocated as a stack (stack). This will give us a lot more performance (M$ said). Okay, Let's take another look at the following example:

From://Structs\struct2.cs
001:using System;
002:
003:class Theclass
004: {
005:public int x;
006:}
007:
008:struct thestruct
009: {
010:public int x;
011:}
012:
013:class TestClass
014: {
015:public static void Structtaker (Thestruct s)
016: {
017:s.x = 5;
018:}
019:public static void Classtaker (Theclass c)
020: {
021:c.x = 5;
022:}
023:public static void Main ()
024: {
025:thestruct a = new thestruct ();
026:theclass B = new Theclass ();
027:a.x = 1;
028:b.x = 1;
029:structtaker (a);
030:classtaker (b);
031:console.writeline ("a.x = {0}", a.x);
032:console.writeline ("b.x = {0}", b.x);
033:}
034:}

The output of this example is:

a.x = 1b.x = 5
As can be seen from this example, when a struct is passed to a method, it is passed only as a copy, and a reference is passed when a class is passed. So the a.x= output is 1, unchanged, and b.x has changed.

The difference is that the structure can be instantiated without new, and the class will. If you do not instantiate a struct with new, all fields will remain unassigned until all fields are initialized. Like classes, structs can execute interfaces. More importantly, the structure has no inheritance, A struct cannot inherit from another class, nor can it be a base class for another class.

Example three:

Interface IImage
{
void Paint ();
}

struct Picture:iimage
{
public void Paint ()
{
Painting Code goes here
}
private int x, y, Z; Other structs Members
}

The above is the Sunwen tutorial----C # Advanced (vii) content, more relevant content please pay attention to topic.alibabacloud.com (www.php.cn)!

