如何在Swift3中获取Json包的内容（unwrap Json package）_app

概述我想在这个帖子里面总结两个问题：一个是通过ReST获取Json的语句，这个比较简单另一个是如何将Json包一层一层转存为字典，并最终通过keyword: String获得所需内容的方法废话不说，来看代码首先是服务器返回的Json形式，这里以youtube API为例，因为google做的Json包很规范（都是 String: String 或者 String: Int） youtube AP

我想在这个帖子里面总结两个问题：一个是通过ReST获取Json的语句，这个比较简单

另一个是如何将Json包一层一层转存为字典，并最终通过keyword: String获得所需内容的方法

废话不说，来看代码

首先是服务器返回的Json形式，这里以youtube API为例，因为Google做的Json包很规范（都是 String: String 或者 String: Int）

youtube API 的请求 URL 形式（我这里仅获取关键字搜索视频列表）是

https://www.GoogleAPIs.com/youtube/v3/search?part=snippet&q=视频关键字&type=vIDeo&key=你的API Key

其中，视频关键字比如 minecraft

API Key 形如AIzaSyDDqTGpVR7jxeozoOEjH6SLaRDW0YY-HPQ

其返回的Json包形式为

{ "kind": "youtube#searchListResponse","etag": "\"uQc-MPTsstrHkQcRXL3IWLmeNsM/dJyYeiv8CbvQiayof_7MqRQOSi8\"","nextPagetoken": "CAUQAA","regionCode": "AU","pageInfo": {  "totalResults": 1000000,"resultsPerPage": 5 },"items": [  {   "kind": "youtube#searchResult","etag": "\"uQc-MPTsstrHkQcRXL3IWLmeNsM/ey6kUbVRRdmcliPpklkbtxDp_-o\"","ID": {    "kind": "youtube#vIDeo","vIDeoID": "XgdgO5UzdR4"   },"snippet": {    "publishedAt": "2016-11-27T12:00:01.000Z","channelID": "UCUVa51UA_690sEKyRbHb-5A","Title": "5 Werewolves Caught on Camera & Spotted In Real life!","description": "5 Werewolves Caught on Tape & Spotted In Real life! Description: Myths and storIEs of humans with the ability to transform into animals exist across all human ...","thumbnails": {     "default": {      "url": "https://i.ytimg.com/vi/XgdgO5UzdR4/default.jpg","wIDth": 120,"height": 90     },"medium": {      "url": "https://i.ytimg.com/vi/XgdgO5UzdR4/mqdefault.jpg","wIDth": 320,"height": 180     },"high": {      "url": "https://i.ytimg.com/vi/XgdgO5UzdR4/hqdefault.jpg","wIDth": 480,"height": 360     }    },"channelTitle": "top 5s Finest","livebroadcastContent": "none"   }  },{   "kind": "youtube#searchResult","etag": "\"uQc-MPTsstrHkQcRXL3IWLmeNsM/LKJrjJEelN2h1v58M533DWv_fJs\"","vIDeoID": "KUS0454UUDM"   },"snippet": {    "publishedAt": "2016-08-03T10:16:33.000Z","channelID": "UC0rzsIrAxF4kCsALP6J2EsA","Title": "MAIN-MAIN: WEREWolF","description": "Yang mau liat tutorial cara mainnya,klik di sini: https://youtu.be/ShGulqRjLMk.","thumbnails": {     "default": {      "url": "https://i.ytimg.com/vi/KUS0454UUDM/default.jpg","medium": {      "url": "https://i.ytimg.com/vi/KUS0454UUDM/mqdefault.jpg","high": {      "url": "https://i.ytimg.com/vi/KUS0454UUDM/hqdefault.jpg","channelTitle": "Raditya Dika","etag": "\"uQc-MPTsstrHkQcRXL3IWLmeNsM/8qIl76CAeB__wn-Sd_g4pik1XT0\"","vIDeoID": "fScsIQ8wgNo"   },"snippet": {    "publishedAt": "2016-10-02T22:21:35.000Z","channelID": "UCNUohh38MTkgY4xKpFeVGmQ","Title": "Werewolf Scenes - My Favorite transformation HD","description": "Werewolf Scenes - My Favorite transformation HD.","thumbnails": {     "default": {      "url": "https://i.ytimg.com/vi/fScsIQ8wgNo/default.jpg","medium": {      "url": "https://i.ytimg.com/vi/fScsIQ8wgNo/mqdefault.jpg","high": {      "url": "https://i.ytimg.com/vi/fScsIQ8wgNo/hqdefault.jpg","channelTitle": "ENJOY PLEASE","etag": "\"uQc-MPTsstrHkQcRXL3IWLmeNsM/SByO_v4iInfFZ5GUe2xJUYXIWh4\"","vIDeoID": "ShGulqRjLMk"   },"snippet": {    "publishedAt": "2016-08-03T10:13:33.000Z","Title": "TUTORIAL: MAIN WEREWolF","description": "Ini adalah vIDeo tutorial untuk main werewolf. Untuk melihat vIDeo permainannya,bisa klik di sini: https://youtu.be/KUS0454UUDM.","thumbnails": {     "default": {      "url": "https://i.ytimg.com/vi/ShGulqRjLMk/default.jpg","medium": {      "url": "https://i.ytimg.com/vi/ShGulqRjLMk/mqdefault.jpg","high": {      "url": "https://i.ytimg.com/vi/ShGulqRjLMk/hqdefault.jpg","etag": "\"uQc-MPTsstrHkQcRXL3IWLmeNsM/njscIZ4D3C-FDPsnBKe-j5tslrE\"","vIDeoID": "MI1Yi2AUVAc"   },"snippet": {    "publishedAt": "2016-09-09T07:27:23.000Z","Title": "Vampire vs Werewolf fight Scene HD - Van Helsing - Vampire vs Lycan Wolf","description": "Vampire vs Werewolf fight Scene HD - Van Helsing - Vampire vs Lycan Wolf.","thumbnails": {     "default": {      "url": "https://i.ytimg.com/vi/MI1Yi2AUVAc/default.jpg","medium": {      "url": "https://i.ytimg.com/vi/MI1Yi2AUVAc/mqdefault.jpg","high": {      "url": "https://i.ytimg.com/vi/MI1Yi2AUVAc/hqdefault.jpg","livebroadcastContent": "none"   }  } ]}
---------------------------------------------------------------------------------------------------------------------
第 0 层 
{}
第一层
{
"kind":"youtube#searchListResponse",
"etag":"\"uQc-MPTsstrHkQcRXL3IWLmeNsM/g4lxZZLl2WXJPiIsotol-Vf33d8\"",
"nextPagetoken":"CAUQAA",
"regionCode":"US",
"pageInfo":{},
"items":[]
}
第二层
对于 pageInfo 
{
"totalResults":1000000,
"resultsPerPage":5
}
对于 items （注意那个中括号）
[[
{
"kind":"youtube#searchResult",
"etag":"\"uQc-MPTsstrHkQcRXL3IWLmeNsM/ey6kUbVRRdmcliPpklkbtxDp_-o\"",
"ID":{},
"snippet":{}
},
{
"kind":"youtube#searchResult",
"etag":"\"uQc-MPTsstrHkQcRXL3IWLmeNsM/LKJrjJEelN2h1v58M533DWv_fJs\"",
"etag":"\"uQc-MPTsstrHkQcRXL3IWLmeNsM/8qIl76CAeB__wn-Sd_g4pik1XT0\"",
"etag":"\"uQc-MPTsstrHkQcRXL3IWLmeNsM/SByO_v4iInfFZ5GUe2xJUYXIWh4\"",
"etag":"\"uQc-MPTsstrHkQcRXL3IWLmeNsM/njscIZ4D3C-FDPsnBKe-j5tslrE\"",
"snippet":{}
}
]
这就是说，中括号里面的内容实际上是一个数组，这个数组有五个元素。

第三层
以其中一个元素为例
对于 ID
{
"kind":"youtube#vIDeo",
"vIDeoID":"XgdgO5UzdR4"
}
对于 snippet
{
"publishedAt":"2016-11-27T12:00:01.000Z",
"channelID":"UCUVa51UA_690sEKyRbHb-5A",
"Title":"5WerewolvesCaughtonCamera&SpottedInReallife!",
"description":"5WerewolvesCaughtonTape&SpottedInReallife!Description:MythsandstorIEsofhumanswiththeabilitytotransformintoanimalsexistacrossallhuman...",
"thumbnails":{},
"channelTitle":"top5sFinest",
"livebroadcastContent":"none"
}
第四层
对于 thumbnails
{
"default":{},
"medium":{},
"high":{}
}
第五层
对于 default 
{
"url":"https://i.ytimg.com/vi/XgdgO5UzdR4/default.jpg",
"wIDth":120,
"height":90
}
其它两个类似

至此Json 包解析完毕。
然后附上代码。首先是ReST请求部分

然后是Json解析部分

只解释Json解析部分。我现在的目的是取出四个key值：视频的Title、description、thumbnail default url 还有 vIDeoID过程是这样：根据我上面的分析，从第一层开始（第 0 层不算）每层都建立[String: AnyObject]字典或数组（根据Json那一层的结构而定）。在最后一层只有String内容的时候，也可以建立[String: String]字典（也就是IDDict也可以建成[String: String]的，别的不可以。）第一层 - resultDict 这个不能建成[String: String]，因为pageInfo和items关键字对应的不是String，而是一个或多个子字典。第二层 - 因为pageInfo里面的内容我不需要（如需要建字典），所以只有items对应的数组 -- itemsArray  （建数组因为items本身是五个元素组成的数组，在前面已经说明。）第三层 - 对于 ID -- IDDict字典，这个可以建[String: AnyObject]也可以建[String: String](因为内容只有String，建AnyObject的话，就需要cast一下(as! String)。)对于 snippet -- snippetDict字典，这个必须[String: AnyObject]第四层 - thumbnailDict第五层 - defaultDict，其它两个Key里面的信息不需要，如果需要，也可以建相应字典提取出来。然后我建了一个每个元素都是[String: AnyObject]字典的Array，形如[[String: AnyObject]]，用来储存我提取出来的四个keyword对应的信息。当然，这个数组建成[[String: String]]也是可以的。当时对这个代码理解还不深，属于半迷糊状态。然后就大功告成。

总结

以上是内存溢出为你收集整理的如何在Swift3中获取Json包的内容（unwrap Json package）全部内容，希望文章能够帮你解决如何在Swift3中获取Json包的内容（unwrap Json package）所遇到的程序开发问题。

如果觉得内存溢出网站内容还不错，欢迎将内存溢出网站推荐给程序员好友。

欢迎分享，转载请注明来源：内存溢出

原文地址: http://outofmemory.cn/web/1090256.html