{"id":7301,"date":"2022-09-07T22:29:00","date_gmt":"2022-09-07T14:29:00","guid":{"rendered":"http:\/\/123.57.164.21\/?p=7301"},"modified":"2022-09-07T22:29:00","modified_gmt":"2022-09-07T14:29:00","slug":"swift%e4%b8%ad%e7%9a%84iboutlet%e7%94%a8-var-%e5%8f%8a-optional-%e5%ae%9a%e4%b9%89%e7%9a%84%e5%8e%9f%e5%9b%a0","status":"publish","type":"post","link":"https:\/\/92it.top\/?p=7301","title":{"rendered":"Swift\u4e2d\u7684@IBOutlet\u7528 var \u53ca Optional \u5b9a\u4e49\u7684\u539f\u56e0"},"content":{"rendered":"\n

\u719f\u6089IOS\u7684\u670b\u53cb\u4eec\u4e00\u5b9a\u5f88\u719f\u6089@IBOutlet\u4e86\uff0c\u5b83\u662f\u94fe\u63a5\u5230\u754c\u9762\u5143\u7d20\uff08storyBoard \u6216 xib\uff09\u7684\u4e00\u4e2a\u53d8\u91cf\u3002<\/p>\n\n\n\n

\u901a\u5e38\u7528\u4ee5\u4e0b\u4ee3\u7801\u8868\u793a\uff1a<\/p>\n\n\n\n

@IBOutlet weak var label: UILabel!<\/pre>\n\n\n\n
\"\"<\/figure><\/div>\n\n\n\n
\u4f46\u662f\u4e3a\u4ec0\u4e48\u8981\u7528 var \u548c Optional \u6765\u58f0\u660e @IBOutlet \u5462\uff1f<\/p>\n\n\n\n
\u6211\u4eec\u6765\u505a\u4e2a\u8bd5\u9a8c\uff0c\u5148\u5c06var\u66ff\u6362\u6210let\uff1a<\/p>\n\n\n\n
\"\"<\/figure><\/div>\n\n\n\n
\u53d1\u751f\u4e24\u4e2a\u9519\u8bef\uff1a<\/p>\n\n\n\n
  • ViewController \u7f3a\u5c11\u521d\u59cb\u5316\u65b9\u6cd5\uff0c<\/li>
  • @IBOutlet \u6807\u8bc6\u7684\u5c5e\u6027\u5fc5\u987b\u662f\u53ef\u53d8\u7684\u3002<\/li><\/ul>\n\n\n\n
    \u63a5\u7740\u7528 UILabel! \u66ff\u6362 UILabel\uff1a<\/p>\n\n\n\n
    \"\"<\/figure><\/div>\n\n\n\n
    \u53d1\u751f\u4e24\u4e2a\u9519\u8bef\uff1a<\/p>\n\n\n\n
    • ViewController \u7f3a\u5c11\u521d\u59cb\u5316\u65b9\u6cd5\uff0c<\/li>
    • @IBOutlet \u4e0d\u80fd\u58f0\u660e\u4e3a\u975e Optional \u7c7b\u578b\u3002<\/li><\/ul>\n\n\n\n
      \u8fd9\u662f\u4e3a\u4ec0\u4e48\u5462\uff1f<\/p>\n\n\n\n
      Swift \u5b98\u65b9\u6587\u6863\u4e2d\u5bf9 initializer \u6709\u5982\u4e0b\u89e3\u91ca\uff1a<\/p>\n\n\n\n
      \u201cInitialization involves setting an initial value for each stored property on that instance and performing any other setup or initialization that is required before the new instance is ready for use.\u201d<\/p>\n\n\n\n
      \u610f\u601d\u662f\uff0c\u5728\u7c7b\u7684\u65b0\u5b9e\u4f8b\u53ef\u7528\u4e4b\u524d\u5fc5\u987b\u6267\u884c\u6784\u9020\u8fc7\u7a0b\uff0c\u8fd9\u4e2a\u8fc7\u7a0b\u5305\u62ec\u8bbe\u7f6e\u5b9e\u4f8b\u4e2d\u6bcf\u4e2a\u5b58\u50a8\u5c5e\u6027\u7684\u521d\u59cb\u503c\u5e76\u6267\u884c\u5176\u5b83\u5fc5\u987b\u7684\u8bbe\u7f6e\u6216\u521d\u59cb\u5316\u5de5\u4f5c\u3002\u5373\u7c7b\u7684\u6bcf\u4e2a\u5c5e\u6027\u5305\u62ec@IBOutlet\uff0c\u5728 init() \u9636\u6bb5\u90fd\u5fc5\u987b\u88ab\u8d4b\u503c\u3002<\/p>\n\n\n\n
      \u7531\u4e8e @IBOutlet \u5bf9\u5e94\u7684\u754c\u9762\u5143\u7d20\u5728 loadView() \u624d\u4f1a\u88ab\u52a0\u8f7d\uff0c\u800c loadView() \u53c8\u662f\u5728 init() \u4e4b\u540e\u624d\u4f1a\u88ab\u6267\u884c\u7684\uff0c\u6240\u4ee5\u5728 init \u9636\u6bb5\uff0c@IBOutlet\u8fd8\u672a\u88ab\u521d\u59cb\u5316\uff0c\u5373\u4f7f @IBOutlet \u5728\u521d\u59cb\u5316\u5b8c\u6210\u4e4b\u540e\u5176\u6307\u9488\u6307\u5411\u7684\u5bf9\u8c61\u4e0d\u4f1a\u518d\u6539\u53d8\uff0c\u4f46\u662f\uff0c\u76f8\u5bf9\u800c\u8a00\u5b83\u8fd8\u662f\u4e00\u4e2a\u53d8\u91cf\u3002\u6240\u4ee5\u9700\u8981\u7528 var \u58f0\u660e\u3002<\/p>\n\n\n\n
      \u65e2\u7136 @IBOutlet\u5728 loadView() \u65f6\u624d\u4f1a\u88ab\u52a0\u8f7d\uff0c\u90a3\u4e48\u5b83\u5728 init \u9636\u6bb5\u7684\u503c\u5c31\u4e3a nil \uff0c\u800c UILabel \u4e0d\u80fd\u591f\u88ab nil \u8d4b\u503c\uff0c\u56e0\u6b64\u6211\u4eec\u9700\u8981\u9009\u62e9\u5b9a\u4e49\u5b83\u4e3a Optional\u3002Optional \u80fd\u591f\u5141\u8bb8\u53d8\u91cf\u5728 init() \u9636\u6bb5\u4e3a nil\uff0cloadView() \u65f6\u518d\u5b8c\u6210\u521d\u59cb\u5316\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
      \u719f\u6089IOS\u7684\u670b\u53cb\u4eec\u4e00\u5b9a\u5f88\u719f\u6089@IBOutlet\u4e86\uff0c\u5b83\u662f\u94fe\u63a5\u5230\u754c\u9762\u5143\u7d20\uff08storyBoard \u6216 xib\uff09\u7684\u4e00\u4e2a […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6,8],"tags":[],"_links":{"self":[{"href":"https:\/\/92it.top\/index.php?rest_route=\/wp\/v2\/posts\/7301"}],"collection":[{"href":"https:\/\/92it.top\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/92it.top\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/92it.top\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/92it.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=7301"}],"version-history":[{"count":1,"href":"https:\/\/92it.top\/index.php?rest_route=\/wp\/v2\/posts\/7301\/revisions"}],"predecessor-version":[{"id":7306,"href":"https:\/\/92it.top\/index.php?rest_route=\/wp\/v2\/posts\/7301\/revisions\/7306"}],"wp:attachment":[{"href":"https:\/\/92it.top\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=7301"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/92it.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=7301"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/92it.top\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=7301"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}