memcpy function usage

DependencyInjection(DI)inC#isadesignpatternthatenhancesmodularity,testability,andmaintainabilitybyallowingclassestoreceivedependenciesexternally.1.DIpromotesloosecouplingbydecouplingobjectcreationfromusage.2.Itsimplifiestestingthroughmockobjectinject

The role of IDisposable and using in C# is to efficiently and deterministically manage unmanaged resources. 1. IDisposable provides Dispose() method, so that the class can clearly define how to release unmanaged resources; 2. The using statement ensures that Dispose() is automatically called when the object is out of scope, simplifying resource management and avoiding leakage; 3. When using it, please note that the object must implement IDisposable, can declare multiple objects, and should always use using for types such as StreamReader; 4. Common best practices include not relying on destructors to clean up, correctly handling nested objects, and implementing the Dispose(bool) pattern.

SOLID principle is five design principles to improve code maintainability and scalability in object-oriented programming. They are: 1. The single responsibility principle (SRP) requires that the class only assumes one responsibility, such as separating report generation and email sending; 2. The opening and closing principle (OCP) emphasizes that the extension is supported through interfaces or abstract classes without modifying the original code, such as using the IShape interface to realize area calculation of different graphics; 3. The Richter replacement principle (LSP) requires that the subclass can replace the parent class without destroying logic, such as Square should not mistakenly inherit Rectangle, resulting in abnormal behavior; 4. The interface isolation principle (ISP) advocates the definition of fine-grained interfaces, such as split printing and scanning functions to avoid redundant dependencies; 5. The dependency inversion principle (DIP) advocates the

In C#, the main difference between value types and reference types is in the way of data storage and memory management. 1. The value type directly contains data, usually stored on the stack, such as int, float, bool and struct, with fast access speed and short life cycle; the reference type stores references to the actual data, the object itself is stored on the heap, such as class, string or object, and the reference variables are stored on the stack, relying on garbage collection and cleaning. 2. Copy the actual value when the value type is assigned, and modifying the copy does not affect the original value; copy the reference address when the reference type is assigned, and the two variables point to the same object, and modification will affect each other. 3. The value type cannot be null by default, unless nullable types such as int? are used; the reference type can naturally be nul

Expression trees are used in C# to represent code as data. They enable developers to analyze, modify, or runtime to generate new code by building a tree structure that describes code operations rather than executing code directly. Its core components include parameter expressions, binary expressions, and lambda expressions. Common uses are LINQtoSQL and ORM (such as EntityFramework), where the expression tree enables C# LINQ queries to be translated into SQL statements. Other uses include dynamic filtering and querying, serialization or scripting systems, simulation frameworks, and dependency injection containers. However, it is more appropriate to use normal functions or lambda expressions without the need for inspection or conversion logic. 1. Construct dynamic query; 2. Translate it into other forms

ASP.NETCore is a cross-platform, high-performance framework launched by Microsoft, designed for the development of modern web applications in C#. Its core advantages include: 1. Cross-platform support, which can run on Windows, macOS and Linux, and is compatible with Docker and cloud-native architectures; 2. Modular architecture, which improves performance and flexibility through middleware pipeline loading functions; 3. Built-in dependency injection (DI), supports lifecycle management, and enhances code maintainability and testability; 4. High performance performance, based on Kestrel server, can efficiently handle high concurrent requests under default configuration, suitable for scenarios with limited resources or high response speed requirements.

CustomAttributes are mechanisms used in C# to attach metadata to code elements. Its core function is to inherit the System.Attribute class and read through reflection at runtime to implement functions such as logging, permission control, etc. Specifically, it includes: 1. CustomAttributes are declarative information, which exists in the form of feature classes, and are often used to mark classes, methods, etc.; 2. When creating, you need to define a class inherited from Attribute, and use AttributeUsage to specify the application target; 3. After application, you can obtain feature information through reflection, such as using Attribute.GetCustomAttribute();

The .NET garbage collector optimizes memory management performance by dividing objects into three generations (Gen0, Gen1, Gen2). The new object belongs to Gen0, and the objects that have not been released have been gradually promoted to a higher generation after multiple recycles. 1. Gen0 contains newly allocated objects, which are usually short-lived; 2. surviving objects that have undergone a recycling enter Gen1; 3. surviving objects that still survive after recycling enter Gen2. Long-term objects such as caches or singletons will eventually be located in this generation. GC prioritizes recycling of low-generation objects, reducing the memory range per scan, thereby improving efficiency. In most cases, developers do not need to care about the generation mechanism, but in scenarios such as high frequency allocation, improper event handling, and incorrect use of Finalizer or IDisposable,