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How to understand ASP.NET 2.0 generics, many novices are not very clear about this, in order to help you solve this problem, the following editor will explain for you in detail, people with this need can come to learn, I hope you can gain something.

As an updated version of # 1.X, Category 2.0 introduces a lot of new and practical features. The most important ones are ASP.NET 2.0 generics (Generics), anonymous methods (Anonymous Methods), iterators (Iterators), and local classes (partial Types). These new features not only provide a high degree of compatibility, but also greatly improve the efficiency and security of the code.

In this section, we learn about ASP.NET 2.0 generics. The necessity of generics: in version 1.X, in order to adapt to the introduction of different types of parameters, we often need to rewrite some functions, or often object them, in order to achieve the versatility of the function. However, it often brings us the decline of program performance and the increase of repetitive labor. The emergence of generics solves this problem very well. In a nutshell, generics are a mechanism that can pass or flexibly standardize parameter types.

Generics need the support of namespace System.Collections.Generic, and can be applied to the design of classes, methods, structures, interfaces, delegates, etc., which integrates reusability, type safety and high efficiency. Let's take a look at several ways to use generics with examples.

1. ASP.NET 2.0 generic method

Using System; using System.Collections.Generic; public class GenericMethod {/ / static generic method public static string Output < T > (T t) {return "type:" + t.GetType (). ToString () + "; value:" + t.ToString ();} public partial class Generic_Method: System.Web.UI.Page {protected void Page_Load (object sender, EventArgs e) {Response.Write (GenericMethod.Output < int > (23) + "< br / >"); Response.Write (GenericMethod.Output < DateTime > (DateTime.Now) + "< br / >");}}

2. ASP.NET 2.0 generic abstract class

Using System; using System.Collections.Generic; / / generic abstract class public abstract class GenericParent {/ / generic abstract method, the return value is a generic type, and a constraint is added to make the generic X inherit from the generic Y public abstract X Output < X, Y > (X x, Y) where X: y / / generic abstract method, the return value is a string type, and a constraint is added to make generic X inherit from IListSource public abstract string Output2 < X > (X x) where X: System.ComponentModel. IListSource;} public class GenericChild: GenericParent {/ / override the generic method public override T Output < T, Z > (T t, Z z) {return t;} / / override the generic method public override string Output2 < T > (T t) {return t.GetType (). ToString () } public partial class Generic_Abstract: System.Web.UI.Page {protected void Page_Load (object sender, EventArgs e) {GenericChild gc = new GenericChild (); Response.Write (gc.Output < string, IComparable > ("aaa", "xxx")); Response.Write ("< br / >"); Response.Write (gc.Output2 < System.Data.DataTable > (new System.Data.DataTable () Response.Write ("< br / >");}}

3. ASP.NET 2.0 generic interface

Using System; using System.Collections.Generic; / / generic interface public interface IGenericInterface < T > {T CreateInstance () } / / A generic class that implements the above generic interface / / derived constraint where T: TI (T inherits from TI) / / Constructor constraint where T: new () (T can be instantiated) public class Factory < T, TI >: IGenericInterface < TI > where T: TI, new () {public TI CreateInstance () {return new T () }} public partial class Generic_Interface: System.Web.UI.Page {protected void Page_Load (object sender, EventArgs e) {IGenericInterface < System.ComponentModel. IListSource > factory = new Factory < System.Data.DataTable, System.ComponentModel.IListSource > (); Response.Write (factory.CreateInstance (). GetType () .ToString (); Response.Write ("< br / >");}}

4. ASP.NET 2.0 generic delegation

Using System; using System.Collections.Generic; public class GenericDelegate {/ / declares a generic delegate public delegate string OutputDelegate < T > (T t); / / defines a static method public static string DelegateFun (string s) {return String.Format ("Hello, {0}", s) } / / define a static method public static string DelegateFun (DateTime dt) {return String.Format ("Time, {0}", dt.ToString ());}} public partial class Generic_Delegate: System.Web.UI.Page {protected void Page_Load (object sender, EventArgs e) {/ / use generic delegate GenericDelegate.OutputDelegate < string > delegate1 = new GenericDelegate.OutputDelegate < string > (GenericDelegate.DelegateFun) Response.Write (delegate1 ("aabbcc")); Response.Write ("< br / >"); / / using generic delegates (anonymous methods) GenericDelegate.OutputDelegate < DateTime > delegate2 = GenericDelegate.DelegateFun; Response.Write (delegate2 (DateTime.Now));}} is it helpful for you to read the above? If you want to know more about the relevant knowledge or read more related articles, please follow the industry information channel, thank you for your support.

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