{"id":4129,"date":"2025-05-31T12:07:32","date_gmt":"2025-06-05T04:13:32","guid":{"rendered":"https:\/\/badgameshow.com\/steven\/?p=4129"},"modified":"2025-06-05T12:07:32","modified_gmt":"2025-06-05T04:13:32","slug":"%e4%ba%86%e8%a7%a3swift%e4%b8%ad%e4%b8%8d%e8%83%bd%e5%b0%8dget-only%e5%b1%ac%e6%80%a7%e9%80%b2%e8%a1%8c%e8%b3%a6%e5%80%bc%e7%9a%84%e5%8e%9f%e5%9b%a0-2","status":"publish","type":"post","link":"https:\/\/badgameshow.com\/steven\/swift\/%e4%ba%86%e8%a7%a3swift%e4%b8%ad%e4%b8%8d%e8%83%bd%e5%b0%8dget-only%e5%b1%ac%e6%80%a7%e9%80%b2%e8%a1%8c%e8%b3%a6%e5%80%bc%e7%9a%84%e5%8e%9f%e5%9b%a0-2\/","title":{"rendered":"\u6df1\u5165\u89e3\u6790 Swift \u932f\u8aa4\uff1a\u7121\u6cd5\u5c0d Get-Only \u5c6c\u6027\u8ce6\u503c\u7684\u539f\u56e0\u53ca\u89e3\u6c7a\u65b9\u6cd5"},"content":{"rendered":"

<\/p>\n

\u6df1\u5165\u89e3\u6790 Swift \u932f\u8aa4\uff1a\u7121\u6cd5\u5c0d Get-Only \u5c6c\u6027\u8ce6\u503c\u7684\u539f\u56e0\u53ca\u89e3\u6c7a\u65b9\u6cd5<\/h1>\n

Swift \u662f\u4e00\u7a2e\u5f37\u5927\u7684\u7a0b\u5f0f\u8a9e\u8a00\uff0c\u7136\u800c\u5728\u4f7f\u7528\u904e\u7a0b\u4e2d\uff0c\u958b\u767c\u8005\u7d93\u5e38\u6703\u9047\u5230\u5404\u7a2e\u932f\u8aa4\u8a0a\u606f\u3002\u5176\u4e2d\u4e00\u500b\u5e38\u898b\u7684\u932f\u8aa4\u662f\u300cCannot assign to value: ‘X’ is a get-only property\u300d\u3002\u9019\u610f\u5473\u8457\u60a8\u6b63\u5728\u5617\u8a66\u5c0d\u4e00\u500b\u53ea\u80fd\u8b80\u53d6\u7684\u5c6c\u6027\u9032\u884c\u8ce6\u503c\uff0c\u9019\u5728 Swift \u4e2d\u662f\u88ab\u7981\u6b62\u7684\u3002<\/p>\n

\u70ba\u4f55\u6703\u51fa\u73fe\u9019\u500b\u932f\u8aa4\uff1f<\/h2>\n

\u9019\u500b\u932f\u8aa4\u7684\u6839\u672c\u539f\u56e0\u5728\u65bc Swift \u4e2d\u7684\u5c6c\u6027\u5b9a\u7fa9\u3002\u5c6c\u6027\u53ef\u4ee5\u88ab\u6a19\u8a18\u70ba\u53ea\u80fd\u8b80\u53d6\uff08get-only\uff09\uff0c\u9019\u610f\u5473\u8457\u60a8\u53ea\u80fd\u5f9e\u4e2d\u7372\u53d6\u503c\uff0c\u537b\u7121\u6cd5\u5c07\u65b0\u503c\u8ce6\u7d66\u5b83\u3002\u9019\u6a23\u7684\u8a2d\u8a08\u63d0\u9ad8\u4e86\u7a0b\u5f0f\u7684\u5b89\u5168\u6027\u8207\u7a69\u5b9a\u6027\u3002<\/p>\n

\u7bc4\u4f8b\u89e3\u8aaa<\/h2>\n

\u8b93\u6211\u5011\u900f\u904e\u4e00\u500b\u5177\u9ad4\u7684\u7bc4\u4f8b\u4f86\u7406\u89e3\u9019\u500b\u932f\u8aa4\u3002\u5047\u8a2d\u60a8\u6709\u4e00\u500b\u540d\u70ba `Person` \u7684\u985e\u5225\uff0c\u5b83\u64c1\u6709\u4e00\u500b\u53ea\u80fd\u8b80\u53d6\u7684\u5c6c\u6027 `name`\uff1a<\/p>\n

class Person {\n    let name: String\n    init(name: String) {\n        self.name = name\n    }\n}\n<\/code><\/pre>\n
\u5728\u9019\u500b\u4f8b\u5b50\u4e2d\uff0c`name` \u5c6c\u6027\u88ab\u5b9a\u7fa9\u70ba `let`\uff0c\u56e0\u6b64\u5b83\u662f\u53ea\u80fd\u8b80\u53d6\u7684\u3002\u5982\u679c\u60a8\u5617\u8a66\u5c0d `name` \u5c6c\u6027\u8ce6\u503c\uff0c\u5c07\u6703\u51fa\u73fe\u4ee5\u4e0b\u932f\u8aa4\uff1a<\/p>\n
let person = Person(name: \"John\")\nperson.name = \"Jane\" \/\/ \u932f\u8aa4\uff1aCannot assign to value: 'name' is a get-only property\n<\/code><\/pre>\n
\u5982\u4f55\u89e3\u6c7a\u9019\u500b\u554f\u984c\uff1f<\/h2>\n
\u8981\u89e3\u6c7a\u6b64\u554f\u984c\uff0c\u60a8\u9700\u8981\u5c07 `name` \u5c6c\u6027\u5b9a\u7fa9\u70ba\u53ef\u8b80\u5beb\uff08read-write\uff09\uff0c\u9019\u6a23\u5c31\u53ef\u4ee5\u5c0d\u5b83\u8ce6\u503c\u3002\u65b9\u6cd5\u662f\u5c07 `let` \u6539\u70ba `var`\uff1a<\/p>\n
class Person {\n    var name: String \/\/ \u6539\u70ba var\uff0c\u73fe\u5728\u53ef\u4ee5\u8ce6\u503c\n    init(name: String) {\n        self.name = name\n    }\n}\n\nlet person = Person(name: \"John\")\nperson.name = \"Jane\" \/\/ \u73fe\u5728\u53ef\u4ee5\u6b63\u5e38\u8ce6\u503c\n<\/code><\/pre>\n
\u9019\u6a23\uff0c\u60a8\u5c31\u80fd\u5920\u9806\u5229\u5730\u5c0d `name` \u5c6c\u6027\u9032\u884c\u8ce6\u503c\uff0c\u800c\u4e0d\u6703\u518d\u9047\u5230\u932f\u8aa4\u8a0a\u606f\u3002<\/p>\n
\u7e3d\u7d50<\/h2>\n
\u300cCannot assign to value: ‘X’ is a get-only property\u300d\u662f Swift \u4e2d\u4e00\u500b\u5e38\u898b\u7684\u932f\u8aa4\u8a0a\u606f\uff0c\u4e3b\u8981\u662f\u56e0\u70ba\u60a8\u5617\u8a66\u5c0d\u4e00\u500b\u53ea\u80fd\u8b80\u53d6\u7684\u5c6c\u6027\u9032\u884c\u8ce6\u503c\u3002\u70ba\u4e86\u89e3\u6c7a\u8a72\u932f\u8aa4\uff0c\u60a8\u53ef\u4ee5\u5c07\u8a72\u5c6c\u6027\u5b9a\u7fa9\u70ba `var`\uff0c\u4f7f\u5176\u53ef\u8b80\u5beb\u3002\u9019\u4e0d\u50c5\u89e3\u6c7a\u4e86\u932f\u8aa4\uff0c\u9084\u5e6b\u52a9\u60a8\u66f4\u597d\u5730\u7406\u89e3 Swift \u4e2d\u5c6c\u6027\u7684\u5de5\u4f5c\u539f\u5247\u3002<\/p>\n
Q&A\uff08\u5e38\u898b\u554f\u984c\u89e3\u7b54\uff09<\/h2>\n
1. \u5982\u4f55\u5224\u65b7\u4e00\u500b\u5c6c\u6027\u662f get-only \u9084\u662f\u53ef\u5beb\u7684\uff1f<\/h3>\n
\u60a8\u53ef\u4ee5\u901a\u904e\u67e5\u770b\u5c6c\u6027\u7684\u5b9a\u7fa9\u4f86\u5224\u65b7\u3002\u5982\u679c\u5c6c\u6027\u4f7f\u7528 `let` \u5b9a\u7fa9\uff0c\u90a3\u9ebc\u5b83\u662f get-only\uff1b\u5982\u679c\u4f7f\u7528 `var` \u5b9a\u7fa9\uff0c\u90a3\u9ebc\u5b83\u662f\u53ef\u5beb\u7684\u3002<\/p>\n
2. \u662f\u5426\u53ef\u4ee5\u5c07 get-only \u5c6c\u6027\u6539\u70ba\u53ef\u5beb\u5c6c\u6027\uff1f<\/h3>\n
\u53ef\u4ee5\uff0c\u53ea\u9700\u5c07\u5c6c\u6027\u5b9a\u7fa9\u5f9e `let` \u6539\u70ba `var`\uff0c\u9019\u6a23\u5c31\u53ef\u4ee5\u5c0d\u5176\u8ce6\u503c\u4e86\u3002<\/p>\n
3. \u6709\u54ea\u4e9b\u60c5\u6cc1\u4e0b\u61c9\u8a72\u4f7f\u7528 get-only \u5c6c\u6027\uff1f<\/h3>\n
\u7576\u60a8\u5e0c\u671b\u78ba\u4fdd\u5c6c\u6027\u7684\u503c\u4e0d\u88ab\u4fee\u6539\u6642\uff0c\u53ef\u4ee5\u4f7f\u7528 get-only \u5c6c\u6027\uff0c\u9019\u6a23\u53ef\u4ee5\u63d0\u9ad8\u8cc7\u6599\u7684\u5b89\u5168\u6027\u548c\u7a69\u5b9a\u6027\u3002<\/p>\n
—<\/p>\n","protected":false},"excerpt":{"rendered":"
\u6587\u7ae0\u6458\u8981\uff1a\u672c\u6587\u5c07\u89e3\u91cbSwift\u4e2d\u4e0d\u80fd\u5c0dGet-Only\u5c6c\u6027\u9032\u884c\u8ce6\u503c\u7684\u539f\u56e0\uff0c\u4e26\u63d0\u4f9b\u4e00\u4e9b\u89e3\u6c7a\u65b9\u6848\uff0c\u8b93\u958b\u767c\u8005\u80fd\u5920\u6b63\u78ba\u4f7f\u7528Get-Only\u5c6c\u6027\u3002<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[174,5],"tags":[173,9],"class_list":["post-4129","post","type-post","status-publish","format-standard","hentry","category-ios","category-swift","tag-ios","tag-swift"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack-related-posts":[],"jetpack_shortlink":"https:\/\/wp.me\/pcFK27-14B","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/badgameshow.com\/steven\/wp-json\/wp\/v2\/posts\/4129","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/badgameshow.com\/steven\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/badgameshow.com\/steven\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/badgameshow.com\/steven\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/badgameshow.com\/steven\/wp-json\/wp\/v2\/comments?post=4129"}],"version-history":[{"count":1,"href":"https:\/\/badgameshow.com\/steven\/wp-json\/wp\/v2\/posts\/4129\/revisions"}],"predecessor-version":[{"id":4130,"href":"https:\/\/badgameshow.com\/steven\/wp-json\/wp\/v2\/posts\/4129\/revisions\/4130"}],"wp:attachment":[{"href":"https:\/\/badgameshow.com\/steven\/wp-json\/wp\/v2\/media?parent=4129"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/badgameshow.com\/steven\/wp-json\/wp\/v2\/categories?post=4129"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/badgameshow.com\/steven\/wp-json\/wp\/v2\/tags?post=4129"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}