{"id":4556,"date":"2021-12-14T17:38:53","date_gmt":"2021-12-14T09:38:53","guid":{"rendered":"http:\/\/123.57.164.21\/?p=4556"},"modified":"2021-12-14T17:38:53","modified_gmt":"2021-12-14T09:38:53","slug":"swiftui%e7%9a%84-geometryreader","status":"publish","type":"post","link":"https:\/\/92it.top\/?p=4556","title":{"rendered":"SwiftUI\u7684 GeometryReader"},"content":{"rendered":"\n

SwiftUI\u7684\u00a0GeometryReader<\/code>\u00a0\u5141\u8bb8\u6211\u4eec\u6839\u636e\u5176\u81ea\u8eab\u7684\u5927\u5c0f\u548c\u5750\u6807\u6765\u786e\u5b9a\u89c6\u56fe\u7684\u5927\u5c0f\u548c\u5750\u6807\uff0c\u8fd9\u662f\u5728SwiftUI\u4e2d\u521b\u5efa\u4e00\u4e9b\u51fa\u8272\u7684\u6548\u679c\u7684\u5173\u952e\u3002<\/p>\n\n\n\n

\u5728\u4f7f\u7528GeometryReader<\/code>\u65f6\uff0c\u60a8\u5e94\u59cb\u7ec8\u7262\u8bb0SwiftUI\u7684\u4e09\u6b65\u5e03\u5c40\u7cfb\u7edf\uff1a\u7236\u7ea7\u4e3a\u5b50\u7ea7\u63d0\u4f9b\u4e86\u4e00\u4e2a\u5c3a\u5bf8\uff0c\u5b50\u7ea7\u4f7f\u7528\u8be5\u5c3a\u5bf8\u786e\u5b9a\u81ea\u5df1\u7684\u5c3a\u5bf8\uff0c\u7236\u7ea7\u4f7f\u7528\u8be5\u5c3a\u5bf8\u9002\u5f53\u5730\u5b9a\u4f4d\u5b50\u7ea7\u3002<\/p>\n\n\n\n

\u5728\u5176\u6700\u57fa\u672c\u7684\u7528\u6cd5\u4e2d\uff0cGeometryReader<\/code>\u7684\u4f5c\u7528\u662f\u8ba9\u6211\u4eec\u8bfb\u53d6\u7236\u7ea7\u63d0\u4f9b\u7684\u5927\u5c0f\uff0c\u7136\u540e\u4f7f\u7528\u8be5\u5927\u5c0f\u6765\u64cd\u7eb5\u6211\u4eec\u7684\u89c6\u56fe\u3002\u4f8b\u5982\uff0c\u6211\u4eec\u53ef\u4ee5\u4f7f\u7528GeometryReader<\/code>\u4f7f\u6587\u672c\u89c6\u56fe\u5177\u6709\u6240\u6709\u53ef\u7528\u7a7a\u95f4\u768490\uff05\uff0c\u800c\u4e0d\u7ba1\u5176\u5185\u5bb9\u662f\u4ec0\u4e48\uff1a<\/p>\n\n\n\n

struct ContentView: View {\n    var body: some View {\n        GeometryReader { geo in\n            Text(\"Hello, World!\")\n                .frame(width: geo.size.width * 0.9)\n                .background(Color.red)\n        }\n    }\n}<\/pre>\n\n\n\n
\u4f20\u5165\u7684\u90a3\u4e2ageo<\/code>\u53c2\u6570\u662f\u4e00\u4e2aGeometryProxy<\/code>\uff0c\u5b83\u5305\u542b\u80fd\u591f\u63d0\u4f9b\u7684\u6700\u5927\u7684\u5c3a\u5bf8\uff0c\u5df2\u5e94\u7528\u7684\u6240\u6709\u5b89\u5168\u533a\u57df\uff0c\u4ee5\u53ca\u4e00\u79cd\u7528\u4e8e\u8bfb\u53d6Frame \u503c\u7684\u65b9\u6cd5\u3002<\/p>\n\n\n\n
GeometryReader<\/code>\u6709\u4e00\u4e2a\u6709\u8da3\u7684\u526f\u4f5c\u7528\uff0c\u53ef\u80fd\u4e00\u5f00\u59cb\u4f1a\u5438\u5f15\u60a8\uff1a\u8fd4\u56de\u7684\u89c6\u56fe\u5177\u6709\u7075\u6d3b\u7684\u9996\u9009\u5927\u5c0f\uff0c\u8fd9\u610f\u5473\u7740\u5b83\u5c06\u6839\u636e\u9700\u8981\u6269\u5c55\u4ee5\u5360\u7528\u66f4\u591a\u7a7a\u95f4\u3002\u5982\u679c\u5c06GeometryReader<\/code>\u653e\u5165VStack<\/code>\u4e2d\uff0c\u7136\u540e\u5728\u5176\u4e0b\u653e\u4e00\u4e9b\u5176\u4ed6\u6587\u672c\uff0c\u5219\u53ef\u4ee5\u770b\u5230\u5b83\u7684\u4f5c\u7528\uff0c\u5982\u4e0b\u6240\u793a\uff1a<\/p>\n\n\n\n
struct ContentView: View {\n    var body: some View {\n        VStack {\n            GeometryReader { geo in\n                Text(\"Hello, World!\")\n                    .frame(width: geo.size.width * 0.9, height: 40)\n                    .background(Color.red)\n            }\n\n            Text(\"More text\")\n                .background(Color.blue)\n        }\n    }\n}<\/pre>\n\n\n\n
\u60a8\u4f1a\u770b\u5230\u201cMore text\u201d\u88ab\u76f4\u63a5\u63a8\u5230\u5c4f\u5e55\u5e95\u90e8\uff0c\u56e0\u4e3aGeometryReader<\/code>\u5360\u636e\u4e86\u6240\u6709\u5269\u4f59\u7a7a\u95f4\u3002\u8981\u67e5\u770b\u5b9e\u9645\u6548\u679c\uff0c\u8bf7\u5c06background(Color.green)<\/code>\u4f5c\u4e3a\u4fee\u6539\u5668\u6dfb\u52a0\u5230GeometryReader<\/code>\u4e2d\uff0c\u60a8\u5c06\u770b\u5230\u5b83\u7684\u5927\u5c0f\u3002\u6ce8\u610f\uff1a\u8fd9\u662f\u9996\u9009\u5927\u5c0f\uff0c\u800c\u4e0d\u662f\u7edd\u5bf9\u5927\u5c0f\uff0c\u8fd9\u610f\u5473\u7740\u5b83\u4ecd\u7136\u53ef\u4ee5\u7075\u6d3b\u5730\u53d6\u51b3\u4e8e\u5176\u7236\u9879\u3002<\/p>\n\n\n\n
\u5728\u8bfb\u53d6\u89c6\u56feFrame\u65f6\uff0cGeometryProxy<\/code>\u63d0\u4f9b\u4e86frame(in :)<\/code>\u65b9\u6cd5\uff0c\u800c\u4e0d\u662f\u7b80\u5355\u7684\u5c5e\u6027\u3002\u8fd9\u662f\u56e0\u4e3a\u201cFrame\u201d\u7684\u6982\u5ff5\u5305\u62ecX\u5750\u6807\u548cY\u5750\u6807\uff0c\u8fd9\u4e9b\u5750\u6807\u5b64\u7acb\u5730\u6ca1\u6709\u4efb\u4f55\u610f\u4e49\u2013\u60a8\u662f\u8981\u89c6\u56fe\u7684\u7edd\u5bf9X\u5750\u6807\u8fd8\u662fY\u5750\u6807\uff0c\u8fd8\u662f\u4e0e\u7236\u89c6\u56fe\u76f8\u6bd4\u5b83\u4eec\u7684X\u5750\u6807\u548cY\u5750\u6807\uff1f<\/p>\n\n\n\n
SwiftUI\u5c06\u8fd9\u4e9b\u9009\u9879\u79f0\u4e3a\u5750\u6807\u7a7a\u95f4\uff0c\u7279\u522b\u662f\u5c06\u8fd9\u4e24\u4e2a\u79f0\u4e3a\u5168\u5c40\u7a7a\u95f4\uff08\u76f8\u5bf9\u4e8e\u6574\u4e2a\u5c4f\u5e55\u8861\u91cf\u6211\u4eec\u7684\u89c6\u56fe\u7a7a\u95f4\uff09\u548c\u5c40\u90e8\u7a7a\u95f4\uff08\u76f8\u5bf9\u4e8e\u5176\u7236\u89c6\u56fe\u8861\u91cf\u6211\u4eec\u7684\u89c6\u56fe\u7a7a\u95f4\uff09\u3002\u6211\u4eec\u8fd8\u53ef\u4ee5\u901a\u8fc7\u5c06ordinateSpace()<\/code>\u4fee\u9970\u7b26\u9644\u52a0\u5230\u89c6\u56fe\u6765\u521b\u5efa\u81ea\u5b9a\u4e49\u5750\u6807\u7a7a\u95f4\uff0c\u7136\u540e\u8be5\u89c6\u56fe\u7684\u4efb\u4f55\u5b50\u9879\u90fd\u53ef\u4ee5\u8bfb\u53d6\u76f8\u5bf9\u4e8e\u8be5\u5750\u6807\u7a7a\u95f4\u7684Frame\u3002<\/p>\n\n\n\n
\u4e3a\u4e86\u6f14\u793a\u5750\u6807\u7a7a\u95f4\u662f\u5982\u4f55\u5de5\u4f5c\u7684\uff0c\u6211\u4eec\u53ef\u4ee5\u5728\u4e0d\u540c\u7684\u5806\u6808\u4e2d\u521b\u5efa\u4e00\u4e9b\u793a\u4f8b\u89c6\u56fe\uff0c\u5c06\u81ea\u5b9a\u4e49\u5750\u6807\u7a7a\u95f4\u9644\u52a0\u5230\u6700\u5916\u9762\u7684\u89c6\u56fe\uff0c\u7136\u540e\u5728\u5176\u4e2d\u7684\u4e00\u4e2a\u89c6\u56fe\u4e2d\u6dfb\u52a0onTapGesture<\/code>\uff0c\u4ee5\u4fbf\u5b83\u53ef\u4ee5\u5168\u5c40\/\u5c40\u90e8\u5730\u6253\u5370Frame\u548c\u4f7f\u7528\u81ea\u5b9a\u4e49\u5750\u6807\u7a7a\u95f4\u3002<\/p>\n\n\n\n
\u5c1d\u8bd5\u5982\u4e0b\u4ee3\u7801\uff1a<\/p>\n\n\n\n
struct OuterView: View {\n    var body: some View {\n        VStack {\n            Text(\"Top\")\n            InnerView()\n                .background(Color.green)\n            Text(\"Bottom\")\n        }\n    }\n}\n\nstruct InnerView: View {\n    var body: some View {\n        HStack {\n            Text(\"Left\")\n            GeometryReader { geo in\n                Text(\"Center\")\n                    .background(Color.blue)\n                    .onTapGesture {\n                        print(\"Global center: \\(geo.frame(in: .global).midX) x \\(geo.frame(in: .global).midY)\")\n                        print(\"Custom center: \\(geo.frame(in: .named(\"Custom\")).midX) x \\(geo.frame(in: .named(\"Custom\")).midY)\")\n                        print(\"Local center: \\(geo.frame(in: .local).midX) x \\(geo.frame(in: .local).midY)\")\n                    }\n            }\n            .background(Color.orange)\n            Text(\"Right\")\n        }\n    }\n}\n\nstruct ContentView: View {\n    var body: some View {\n        OuterView()\n            .background(Color.red)\n            .coordinateSpace(name: \"Custom\")\n    }\n}<\/pre>\n\n\n\n
\u8be5\u4ee3\u7801\u8fd0\u884c\u65f6\u6240\u83b7\u5f97\u7684\u8f93\u51fa\u53d6\u51b3\u4e8e\u60a8\u6240\u4f7f\u7528\u7684\u8bbe\u5907\uff0c\u4f46\u8fd9\u662f\u6211\u5f97\u5230\u7684\uff1a<\/p>\n\n\n\n
  • Global center: 202.0 x 455.16666666666663<\/li>
  • Custom center: 202.0 x 411.16666666666663<\/li>
  • Local center: 164.0 x 378.5<\/li><\/ul>\n\n\n\n
    \u8fd9\u4e9b\u5c3a\u5bf8\u5927\u90e8\u5206\u662f\u4e0d\u540c\u7684\uff0c\u56e0\u6b64\u5e0c\u671b\u60a8\u80fd\u770b\u5230\u8fd9\u4e9b\u6846\u67b6\u5982\u4f55\u5de5\u4f5c\u7684\u5168\u90e8\u5185\u5bb9\uff1a<\/p>\n\n\n\n
    • \u5168\u5c40\u4e2d\u5fc3X\u4e3a202\u8868\u793a\u6587\u672c\u89c6\u56fe\u7684\u4e2d\u5fc3\u8ddd\u79bb\u5c4f\u5e55\u5de6\u8fb9\u7f18202\u4e2a\u70b9\u3002\u8fd9\u5e76\u4e0d\u662f\u5b9a\u6b7b\u5728\u5c4f\u5e55\u4e2d\u592e\uff0c\u56e0\u4e3a\u201cLeft\u201d\u548c\u201cRight\u201d\u6807\u7b7e\u7684\u5c3a\u5bf8\u4e0d\u540c\u3002<\/li>
    • \u5168\u5c40\u4e2d\u5fc3Y\u4e3a455.167\u8868\u793a\u6587\u672c\u89c6\u56fe\u7684\u4e2d\u5fc3\u8ddd\u79bb\u5c4f\u5e55\u9876\u90e8\u8fb9\u7f18455.167\u70b9\u3002\u8fd9\u5e76\u4e0d\u662f\u5b9a\u6b7b\u5728\u5c4f\u5e55\u4e2d\u592e\uff0c\u56e0\u4e3a\u9876\u90e8\u7684\u5b89\u5168\u533a\u57df\u6bd4\u5e95\u90e8\u7684\u5b89\u5168\u533a\u57df\u5927\u3002<\/li>
    • \u81ea\u5b9a\u4e49\u4e2d\u5fc3X\u4e3a202\u8868\u793a\u6587\u672c\u89c6\u56fe\u7684\u4e2d\u5fc3\u8ddd\u62e5\u6709\u201c\u81ea\u5b9a\u4e49\u201d\u5750\u6807\u7a7a\u95f4\u7684\u4efb\u4f55\u89c6\u56fe\u7684\u5de6\u8fb9\u7f18202\u4e2a\u70b9\uff0c\u5728\u672c\u4f8b\u4e2d\u4e3aOuterView<\/code>\uff0c\u56e0\u4e3a\u6211\u4eec\u5c06\u5176\u9644\u52a0\u5230ContentView<\/code>\u4e2d\u3002\u6b64\u6570\u5b57\u4e0e\u5168\u5c40\u4f4d\u7f6e\u5339\u914d\uff0c\u56e0\u4e3aOuterView<\/code>\u6c34\u5e73\u8fb9\u7f18\u6328\u5230\u5c4f\u5e55\u8fb9\u7f18\u3002<\/li>
    • \u81ea\u5b9a\u4e49\u4e2d\u5fc3Y\u4e3a411.167\uff0c\u8868\u793a\u6587\u672c\u89c6\u56fe\u7684\u4e2d\u5fc3\u8ddd\u79bbOuterView<\/code>\u7684\u9876\u90e8\u8fb9\u7f18\u4e3a411.167\u70b9\u3002\u8be5\u503c\u5c0f\u4e8e\u5168\u5c40\u4e2d\u5fc3Y\uff0c\u56e0\u4e3aOuterView<\/code>\u4e0d\u4f1a\u5ef6\u4f38\u5230\u5b89\u5168\u533a\u57df\u3002<\/li>
    • \u5c40\u90e8\u4e2d\u5fc3X\u4e3a164\u8868\u793a\u6587\u672c\u89c6\u56fe\u7684\u4e2d\u5fc3\u8ddd\u79bb\u5176\u76f4\u63a5\u5bb9\u5668\uff08\u5728\u672c\u4f8b\u4e2d\u4e3aGeometryReader<\/code>\uff09\u7684\u5de6\u8fb9\u7f18164\u4e2a\u70b9\u3002<\/li>
    • Y\u7684\u672c\u5730\u4e2d\u5fc3378.5\u8868\u793a\u6587\u672c\u89c6\u56fe\u7684\u4e2d\u5fc3\u8ddd\u79bb\u5176\u76f4\u63a5\u5bb9\u5668\uff08\u4e5f\u662fGeometryReader<\/code>\uff09\u7684\u9876\u90e8\u8fb9\u7f18378.6\u70b9\u3002<\/li><\/ul>\n\n\n\n
      \u60a8\u8981\u4f7f\u7528\u54ea\u4e2a\u5750\u6807\u7a7a\u95f4\u53d6\u51b3\u4e8e\u60a8\u8981\u56de\u7b54\u7684\u95ee\u9898\uff1a<\/p>\n\n\n\n
      • \u662f\u5426\u60f3\u77e5\u9053\u6b64\u89c6\u56fe\u5728\u5c4f\u5e55\u4e0a\u7684\u4f4d\u7f6e\uff1f\u4f7f\u7528\u5168\u5c40\u7a7a\u95f4\u3002<\/li>
      • \u662f\u5426\u60f3\u77e5\u9053\u6b64\u89c6\u56fe\u76f8\u5bf9\u4e8e\u5176\u7236\u89c6\u56fe\u7684\u4f4d\u7f6e\uff1f\u4f7f\u7528\u672c\u5730\u7a7a\u95f4\u3002<\/li>
      • \u8981\u77e5\u9053\u8be5\u89c6\u56fe\u76f8\u5bf9\u4e8e\u5176\u4ed6\u89c6\u56fe\u7684\u4f4d\u7f6e\uff1f\u4f7f\u7528\u81ea\u5b9a\u4e49\u7a7a\u95f4<\/li><\/ul>\n\n\n\n
        <\/p>\n","protected":false},"excerpt":{"rendered":"
        SwiftUI\u7684\u00a0GeometryReader\u00a0\u5141\u8bb8\u6211\u4eec\u6839\u636e\u5176\u81ea\u8eab\u7684\u5927\u5c0f\u548c\u5750\u6807\u6765\u786e\u5b9a\u89c6\u56fe\u7684\u5927\u5c0f\u548c\u5750\u6807\uff0c\u8fd9\u662f\u5728S […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5],"tags":[],"_links":{"self":[{"href":"https:\/\/92it.top\/index.php?rest_route=\/wp\/v2\/posts\/4556"}],"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=4556"}],"version-history":[{"count":1,"href":"https:\/\/92it.top\/index.php?rest_route=\/wp\/v2\/posts\/4556\/revisions"}],"predecessor-version":[{"id":4557,"href":"https:\/\/92it.top\/index.php?rest_route=\/wp\/v2\/posts\/4556\/revisions\/4557"}],"wp:attachment":[{"href":"https:\/\/92it.top\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=4556"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/92it.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=4556"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/92it.top\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=4556"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}