{"id":134946,"date":"2020-07-08T16:44:04","date_gmt":"2020-07-08T08:44:04","guid":{"rendered":"http:\/\/4563.org\/?p=134946"},"modified":"2020-07-08T16:44:04","modified_gmt":"2020-07-08T08:44:04","slug":"kotlin-%e5%a6%82%e4%bd%95%e6%a3%80%e6%b5%8b%e6%89%80%e6%9c%89-lateinit-%e7%9a%84-field-%e6%98%af%e5%90%a6%e5%88%9d%e5%a7%8b%e5%8c%96","status":"publish","type":"post","link":"http:\/\/4563.org\/?p=134946","title":{"rendered":"Kotlin \u5982\u4f55\u68c0\u6d4b\u6240\u6709 lateinit \u7684 field \u662f\u5426\u521d\u59cb\u5316"},"content":{"rendered":"
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Kotlin \u5982\u4f55\u68c0\u6d4b\u6240\u6709 lateinit \u7684 field \u662f\u5426\u521d\u59cb\u5316 <\/h1>\n

<\/p>\n

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\u8cc7\u6df1\u5927\u4f6c : fanck0605 <\/span> <\/i> 13<\/span> <\/div>\n
<\/div>\n<\/p><\/div>\n<\/p><\/div>\n<\/p><\/div>\n
<\/p>\n

\u5728 java \u91cc\uff0c\u6211\u4e00\u822c\u7528\u53cd\u5c04\u904d\u5386\u6240\u6709 Field\uff0c\u5e76\u67e5\u770b\u662f\u5426\u4e3a null<\/p>\n

Example example = new Example();  \/\/ \u8fd9\u91cc\u89e3\u6790\u4e00\u4e9b\u6587\u672c\u5e76\u7ed9 example \u7684\u6210\u5458\u53d8\u91cf\u8d4b\u503c \/\/ do something...  \/\/ \u68c0\u6d4b\u662f\u5426\u6240\u6709\u53d8\u91cf\u90fd\u88ab\u521d\u59cb\u5316 Field[] fields = Example.class.getFields() for (Field field : fields) {     try {      Object o = field.get(example);         if (o == null) {             throw new Exception()\uff1b         }     } catch (IllegalAccessException ignored) {     } } <\/code><\/pre>\n
kotlin \u4ee3\u7801\u4e2d\uff0c\u6240\u6709\u6210\u5458\u53d8\u91cf\u90fd\u7528\u4e86 lateinit \u4fee\u9970\u7b26\uff0c \u90a3\u6709\u6ca1\u6709\u7c7b\u4f3c\u7684\u65b9\u6cd5\u53ef\u4ee5\uff0c\u68c0\u6d4b\u6240\u6709\u53d8\u91cf\u662f\u5426\u88ab initialized<\/p>\n<\/p><\/div>\n
 \u5927\u4f6c\u6709\u8a71\u8aaa<\/b> (6<\/span>)        <\/div>\n
 <\/div>\n<\/p><\/div>\n<\/p><\/div>\n
    \n
  • \n
    \n
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     \u8cc7\u6df1\u5927\u4f6c : holmesabc <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 this::wtf.isInitialized ??                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
     \u8cc7\u6df1\u5927\u4f6c : dcalsky <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 `isInitialized`<\/p>\n
    \u7ed9\u4f60\u5199\u4e86\u4e00\u6bb5\uff0c\u770b\u56fe~<\/p>\n
    https:\/\/sm.ms\/image\/P5VSfbmoh7XrJFg                                                            <\/p><\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
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     \u8cc7\u6df1\u5927\u4f6c : aabbcc112233 <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 @holmesabc 
    @dcalsky \u5ba1\u9898\uff0c\u95ee\u7684\u662f\u5224\u65ad\u6240\u6709\u53d8\u91cf\u3002<\/p>\n
    \u56de\u590d\u4e3b\uff1a
    lateinit \u7684\u7528\u6cd5\u662f\u5f88\u786e\u5b9a\u8fd9\u4e2a\u53d8\u91cf\u4f1a\u5728\u4f7f\u7528\u524d\u88ab\u521d\u59cb\u5316\u3002
    \u5982\u679c\u4e0d\u786e\u5b9a\uff0c\u4f60\u5e94\u8be5\u4f7f\u7528\u53ef\u7a7a\u7c7b\u578b\u6765\u8fbe\u5230\u5b89\u5168\u8c03\u7528                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
     \u8cc7\u6df1\u5927\u4f6c : john6lq <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 @aabbcc112233 \u90a3\u5c31\u62ff\u4e0a\u65b9\u6cd5\u904d\u5386\u554a\uff0c\u4f60\u624d\u662f\u6ca1\u201c\u5ba1\u9898\u201d\u7684\u90a3\u4e2a\u597d\u5427\uff0c\u4eba\u5bb6\u6709\u8fd9\u4e2a\u9700\u6c42\u4f60\u544a\u8bc9\u4ed6\u76f4\u63a5\u780d\u4e86\u800c\u4e0d\u662f\u627e\u89e3\u51b3\u529e\u6cd5\u3002                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
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     \u8cc7\u6df1\u5927\u4f6c : flywith24 <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 \u4e3a Example \u5199\u4e2a\u6269\u5c55\u51fd\u6570\uff0c\u91cc\u9762\u5224\u65ad\u6240\u6709\u5c5e\u6027\u662f\u5426\u521d\u59cb\u5316\uff0c\u4e0d\u77e5\u9053\u662f\u5426\u6ee1\u8db3\u4f60\u7684\u9700\u6c42                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
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     \u4e3b<\/span> \u8cc7\u6df1\u5927\u4f6c : fanck0605 <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 \u6211\u4e5f\u662f\u521a\u5199 Kotlin\uff0c\u6bd4\u8f83\u770b\u4e2d Kotlin \u7684\u5bf9\u7a7a\u503c\u7684\u5904\u7406\uff0c\u8fd8\u6709\u534f\u7a0b\u3002<\/p>\n
    @aabbcc112233 
    \u5982\u679c\u4f7f\u7528\u4e86\u53ef\u7a7a\u7c7b\u578b\uff0c\u90a3\u4e48\u4ee5\u540e\u7684\u8c03\u7528\u90fd\u8981\u52a0 `!!`\uff0c\u867d\u7136\u53ef\u4ee5\u4ece\u4ee3\u7801\u5c42\u9762\u63a7\u5236\u8fd9\u4e9b \u6210\u5458\u53d8\u91cf \u975e\u7a7a\uff0c\u4f46\u662f\u8fd9\u4f3c\u4e4e\u8ba9\u4ee3\u7801\u53d8\u5f97\u4e0d\u591f\u4f18\u96c5\u4e86\u3002<\/p>\n
    @holmesabc @dcalsky 
    \u8fd9\u4e48\u5199\u7684\u786e\u53ef\u4ee5\u5224\u65ad\u5355\u4e2a \u6210\u5458\u53d8\u91cf \uff0c\u7f16\u8bd1\u65f6\uff0c\u6210\u5458\u53d8\u91cf \u4e5f\u662f\u56fa\u5b9a\u7684\uff0c\u4e00\u4e2a\u4e00\u4e2a\u5224\u65ad\u4e5f\u4e0d\u662f\u4e0d\u53ef\u4ee5\u3002
    \u4f46\u6210\u5458\u53d8\u91cf\u5f88\u591a\u65f6\uff0c\u5199\u51fa\u6765\u7684\u4ee3\u7801\u4f3c\u4e4e\u5c31\u4f1a\u5f88\u5197\u957f\u3002<\/p>\n
    \u73b0\u5728\u6211\u662f\u8fd9\u4e48\u5199\u7684\uff0c\u4e0d\u77e5\u9053\u6709\u6ca1\u6709\u4f18\u5316\u7684\u4f59\u5730\u3002
    “`
    class Car {<\/p>\n
     lateinit var field1: String
     lateinit var field2: String
     lateinit var field3: String
     lateinit var name: String
     lateinit var color: String<\/p>\n
     \/\/ \u8fd9\u91cc\u8fd8\u6709\u5f88\u591a\u6210\u5458\u53d8\u91cf<\/p>\n
     companion object {
     val memberProperties = Car::class.memberProperties<\/p>\n
     fun parse(text : String): Car {<\/p>\n
     val car = Car()<\/p>\n
     \/\/ \u8fd9\u91cc\u89e3\u6790\u4e00\u4e9b\u6587\u672c\uff0c\u5e76\u521d\u59cb\u5316 car \u7684\u6210\u5458\u53d8\u91cf
     \/\/ var car.field1 = xxx
     \/\/ var car.field2 = xxx
     \/\/ var car.field3 = xxx<\/p>\n
     \/\/ \u68c0\u6d4b\u662f\u5426\u90fd\u88ab\u521d\u59cb\u5316
     for (memberProperty in memberProperties) {
     try {
     memberProperty.get(car)
     } catch (e: UninitializedPropertyAccessException) {
     \/\/ \u629b\u51fa\u5f02\u5e38\uff0c\u4fdd\u8bc1\u5916\u90e8\u83b7\u5f97\u7684\u5bf9\u8c61\uff0c\u6240\u6709\u53d8\u91cf\u90fd\u88ab initialized
     throw Exception(“${memberProperty.name} is uninitialized! Failed to parse text: $text”)
     }
     }
     return car
     }
     }
    }
    “`                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n","protected":false},"excerpt":{"rendered":"
    Kotlin \u5982\u4f55\u68c0\u6d4b\u6240\u6709 lat…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[],"tags":[],"_links":{"self":[{"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/posts\/134946"}],"collection":[{"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=134946"}],"version-history":[{"count":0,"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/posts\/134946\/revisions"}],"wp:attachment":[{"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=134946"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=134946"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=134946"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}