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系统架构图

基本概念什么是架构架构就是对系统中的实体以及实体之间的关系所进行的抽象描述，是一系列的决策。架构是结构和愿景。系统架构是概念的体现，是对物/信息的功能与形式元素之间的对应情况所做的分配，是对元素之间的关系以及元素同周边环境之间的关系所做的定义。什么是架构图系统架构图是为了抽象地表示软件系统的整体轮廓和各个组件之间的相互关系和约束边界，以及软件系统的物理部署和软件系统的演进方...

Posted by Kerwen Blog on January 16, 2020

SQL-LINQ-EF

Posted by Kerwen Blog on January 12, 2020

线程安全的单例模式

普通单例模式 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 public class Singleton { private static Singleton instance = null; private Singleton() { } public static Singleton I...

Posted by Kerwen Blog on January 7, 2020

C# debug application startup

Add 1 System.Diagnostics.Debugger.Launch(); to Application_Start. You’ll get a popup asking you if you want to debug the website, and if you click OK, you’ll be taken to Visual Studio in debug m...

Posted by Kerwen Blog on January 6, 2020

C# XML序列化

Open xml to copy xml content Create a new class in VS Edit -> Paste Special -> Paste XML as Classes 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 [System.Xml.Serializat...

Posted by Kerwen Blog on January 3, 2020

C#加密解密

Reference How to: Store Asymmetric Keys in a Key Container RSA Encryption, getting bad length RSACryptoServiceProvider encrypt and decrypt using own public and private key Key Storage and Retri...

Posted by Kerwen Blog on December 24, 2019

C# SQLite 性能优化

https://blog.csdn.net/qingzhuyuxian/article/details/79768032 https://zhuanlan.zhihu.com/p/84768332 Write-Ahead Logging SQLite WAL 模式简单介绍 SQLite的原子提交及WAL日志模式

Posted by Kerwen Blog on December 16, 2019

如何限制Task的最大并发数量

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 int maxConcurrency=10; var messages = new List<string>(); using(SemaphoreSlim concurrencySemaphore = new SemaphoreSlim(max...

Posted by Kerwen Blog on December 10, 2019

VisualStudio 升级过程中提示root node is not in the package collection.

升级Visual Studio 2017 到 15.9.16版本时，冒出以下提示： 1 Setup operation failed: The root node "Microsoft.VisualStudio.Product.Professional,version=15.0.26403.7" is not in the package collection. 解决方案： Pleas...

Posted by Kerwen Blog on November 12, 2019

基金进阶课

投资风险单一资产的风险和收益关系成正相关，一般是风险低，回报就低；回报高的，风险也高。马考维茨投资组合有效边界模型：通过将投资品进行组合，在相同的风险下，可能带来更高的收益，也有可能导致收益下滑。风险分类：非系统风险企业经营风险企业财务风险行业风险系统性风险市场风险利率风险当利率上升时，意味着把钱存在银行都能获得还不错的收益，大家当然愿意把钱存...

Posted by Kerwen Blog on November 9, 2019