{"id":12771,"date":"2024-03-14T16:35:22","date_gmt":"2024-03-14T16:35:22","guid":{"rendered":"https:\/\/www.silicloud.com\/blog\/what-is-the-usage-of-readonly-in-c\/"},"modified":"2025-08-05T06:40:59","modified_gmt":"2025-08-05T06:40:59","slug":"what-is-the-usage-of-readonly-in-c","status":"publish","type":"post","link":"https:\/\/www.silicloud.com\/blog\/what-is-the-usage-of-readonly-in-c\/","title":{"rendered":"C# Readonly Usage Explained"},"content":{"rendered":"

In C#, the readonly keyword is used to define read-only fields or read-only properties. It can be used in fields of classes, fields of structures, and auto-implemented properties of classes. Here is how the readonly keyword is used:<\/p>\n

    \n
  1. cannot be changed<\/li>\n<\/ol>\n
    public<\/span> class<\/span> MyClass<\/span> {\r\n    public<\/span> readonly<\/span> int<\/span> MyField = 10<\/span>;\r\n}\r\n\r\n\/\/ \u4f7f\u7528\u53ea\u8bfb\u5b57\u6bb5<\/span>\r\nMyClass obj = new<\/span> MyClass();\r\nConsole.WriteLine(obj.MyField);  \/\/ \u8f93\u51fa\uff1a10<\/span>\r\n<\/code><\/pre>\n
      \n
    1. unchangeable<\/li>\n<\/ol>\n
      public<\/span> class<\/span> MyClass<\/span> {\r\n    public<\/span> int<\/span> MyProperty { get<\/span>; } = 10<\/span>;\r\n}\r\n\r\n\/\/ \u4f7f\u7528\u53ea\u8bfb\u5c5e\u6027<\/span>\r\nMyClass obj = new<\/span> MyClass();\r\nConsole.WriteLine(obj.MyProperty);  \/\/ \u8f93\u51fa\uff1a10<\/span>\r\n<\/code><\/pre>\n
      The values of read-only fields and properties are initialized at the time of declaration or in the constructor, so their values cannot be dynamically modified at runtime.<\/p>\n
      In general, the readonly keyword is used to define read-only fields or properties to ensure that their values remain constant throughout the object’s lifecycle. This can provide more reliable data protection and code security.<\/p>\n","protected":false},"excerpt":{"rendered":"
      In C#, the readonly keyword is used to define read-only fields or read-only properties. It can be used in fields of classes, fields of structures, and auto-implemented properties of classes. Here is how the readonly keyword is used: cannot be changed public class MyClass { public readonly int MyField = 10; } \/\/ \u4f7f\u7528\u53ea\u8bfb\u5b57\u6bb5 MyClass […]<\/p>\n","protected":false},"author":5,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_import_markdown_pro_load_document_selector":0,"_import_markdown_pro_submit_text_textarea":"","footnotes":""},"categories":[1],"tags":[16808,3974,16807,697,16809],"class_list":["post-12771","post","type-post","status-publish","format-standard","hentry","category-uncategorized","tag-c-fields","tag-c-properties","tag-c-readonly","tag-c-best-practices","tag-immutable-programming"],"yoast_head":"\nC# Readonly Usage Explained - Blog - Silicon Cloud<\/title>\n<meta name=\"description\" content=\"Learn how to use the readonly keyword in C# for creating immutable fields and properties.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.silicloud.com\/blog\/what-is-the-usage-of-readonly-in-c\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"C# Readonly Usage Explained\" \/>\n<meta property=\"og:description\" content=\"Learn how to use the readonly keyword in C# for creating immutable fields and properties.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.silicloud.com\/blog\/what-is-the-usage-of-readonly-in-c\/\" \/>\n<meta property=\"og:site_name\" content=\"Blog - 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