请问如何详细解释C概念？

本文共计2352个文字，预计阅读时间需要10分钟。

一、C语言基础入门

1.C语言简介

2.程序的编写与运行

3.数据类型与变量

4.运算符与表达式

5.控制结构

6.函数

7.数组

8.指针

9.结构体与联合体

10.位操作

11.预处理器

12.文件操作

13.动态内存分配

14.错误处理

15.编程实践与技巧

一、C#对XML格式数据的解析

1、用XMLDocument来解析

XmlDocument xmlDocument = new XmlDocument(); xmlDocumentLoad("testxml"); //创建新节点 XmlElement nn = xmlDocumentCreateElement("image"); nnSetAttribute("imageUrl", "jpg"); XmlNode node = xmlDocumentSelectSingleNode("content/section/page/gall/folder");//定位到folder节点 nodeAppendChild(nn);//附加新节点 //保存 xmlDocumentSave("testxml");

2、用Linq to XML来解析

可以通过遍历，来获得你想要的节点的内容或属性

XElement root = XElementLoad("testxml"); foreach (XAttribute att in rootAttributes()) { rootAdd(new XElement(attName, (string)att)); } ConsoleWriteLine(root);

3、附一个详细点的例子

比如要解析如下的xml文件，将其转化为Ilist对象。

<?xml version="0" encoding="utf-8"?> <Car> <carcost> <ID>20130821133126</ID> <uptime>60</uptime> <downtime>30</downtime> <price>4</price> </carcost> <carcost> <ID>20130821014316</ID> <uptime>120</uptime> <downtime>60</downtime> <price>3</price> </carcost> <carcost> <ID>20130822043127</ID> <uptime>30</uptime> <downtime>0</downtime> <price>5</price> </carcost> <carcost> <ID>20130822043341</ID> <uptime>120以上！</uptime> <downtime>120</downtime> <price>2</price> </carcost> </Car>

在控制台应用程序中输入如下代码即可。

class Program { static void Main(string[] args) { IList<CarCost> resultList = new List<CarCost>(); XmlDocument xmlDocument = new XmlDocument(); xmlDocumentLoad("testxml"); XmlNodeList xmlNodeList = xmlDocumentSelectSingleNode("Car")ChildNodes; foreach (XmlNode list in xmlNodeList) { CarCost carcost = new CarCost ( listSelectSingleNode("ID")InnerText, listSelectSingleNode("uptime")InnerText, listSelectSingleNode("downtime")InnerText, floatParse(listSelectSingleNode("price")InnerText) ); resultListAdd(carcost); } IEnumerator enumerator = resultListGetEnumerator(); while (enumeratorMoveNext()) { CarCost carCost = enumeratorCurrent as CarCost; ConsoleWriteLine(carCostID + " " + carCostUpTime + " " + carCostDownTime + " " + carCostPrice); } } } public class CarCost { public CarCost(string id, string uptime, string downtime, float price) { thisID = id; thisUpTime = uptime; thisDownTime = downtime; thisPrice = price; } public string ID { get; set; } public string UpTime { get; set; } public string DownTime { get; set; } public float Price { get; set; } }

二、C#对JSON格式数据的解析

引用NewtonsoftJsondll文件，来解析。

比如：有个要解析的JSON字符串

[{"TaskRoleSpaces":"","TaskRoles":"","ProxyUserID":"5d9ad5dc1c5e494db1d1b4d8d79b60a7","UserID":"5d9ad5dc1c5e494db1d1b4d8d79b60a7","UserName":"姓名","UserSystemName":"2234","OperationName":"送合同负责人","OperationValue":"同意","OperationValueText":"","SignDate":"2013-06-19 10:31:26","Comment":"同意","FormDataHashCode":"","SignatureDivID":""},{"TaskRoleSpaces":"","TaskRoles":"","ProxyUserID":"2c96c3943826ea93013826eafe6d0089","UserID":"2c96c3943826ea93013826eafe6d0089","UserName":"姓名2","UserSystemName":"1234","OperationName":"送合同负责人","OperationValue":"同意","OperationValueText":"","SignDate":"2013-06-20 09:37:11","Comment":"同意","FormDataHashCode":"","SignatureDivID":""}]

首先定义个实体类：

public class JobInfo { public string TaskRoleSpaces { get; set; } public string TaskRoles { get; set; } public string ProxyUserID { get; set; } public string UserID { get; set; } public string UserName { get; set; } public string UserSystemName { get; set; } public string OperationName { get; set; } public string OperationValue { get; set; } public string OperationValueText { get; set; } public DateTime SignDate { get; set; } public string Comment { get; set; } public string FormDataHashCode { get; set; } public string SignatureDivID { get; set; } }

然后在控制台Main函数内部输入如下代码：

string json = @"[{'TaskRoleSpaces':'','TaskRoles':'','ProxyUserID':'5d9ad5dc1c5e494db1d1b4d8d79b60a7','UserID':'5d9ad5dc1c5e494db1d1b4d8d79b60a7','UserName':'姓名','UserSystemName':'2234','OperationName':'送合同负责人','OperationValue':'同意','OperationValueText':'','SignDate':'2013-06-19 10:31:26','Comment':'同意','FormDataHashCode':'','SignatureDivID':''},{'TaskRoleSpaces':'','TaskRoles':'','ProxyUserID':'2c96c3943826ea93013826eafe6d0089','UserID':'2c96c3943826ea93013826eafe6d0089','UserName':'姓名2','UserSystemName':'1234','OperationName':'送合同负责人','OperationValue':'同意','OperationValueText':'','SignDate':'2013-06-20 09:37:11','Comment':'同意','FormDataHashCode':'','SignatureDivID':''}] "; List<JobInfo> jobInfoList = JsonConvertDeserializeObject<List<JobInfo>>(json); foreach (JobInfo jobInfo in jobInfoList) { ConsoleWriteLine("UserName:" + jobInfoUserName + "UserID:" + jobInfoUserID); }

这样就可以正常输出内容了。

我想肯定有人会问，如果有多层关系的json字符串该如何处理呢？没关系，一样的处理。

比如如何解析这个json字符串：[{'phantom':true,'id':'20130717001','data':{'MID':1019,'Name':'aaccccc','Des':'cc','Disable':'启用','Remark':'cccc'}}] ？

首先还是定义实体类：

public class Info { public string phantom { get; set; } public string id { get; set; } public data data { get; set; } } public class data { public int MID { get; set; } public string Name { get; set; } public string Des { get; set; } public string Disable { get; set; } public string Remark { get; set; } }

然后在main方法里面，键入：

string json = @"[{'phantom':true,'id':'20130717001','data':{'MID':1019,'Name':'aaccccc','Des':'cc','Disable':'启用','Remark':'cccc'}}]"; List<Info> infoList = JsonConvertDeserializeObject<List<Info>>(json); foreach (Info info in infoList) { ConsoleWriteLine("id:" + infodataMID); }

按照我们的预期，应该能够得到1019的结果。

截图为证：

再附一个JSON解析的例子，来自于兔子家族—二哥在本篇博客下的回复。

JSON字符串1：{success:true,data:{id:100001,code:\"JTL-Z38005\",name:\"奥迪三轮毂\",location:\"A-202\",qty:100,bins:[{code:\"JTL-Z38001\",name:\"奥迪三轮毂\",location:\"A-001\",qty:100},{ code:\"JTL-Z38002\",name:\"奥迪三轮毂\",location:\"A-002\",qty:100}]}}

定义数据结构：

public class Data { public Boolean success { get; set; } public Data1 data { get; set; } } public class Data1 { public Int32 id { get; set; } public string code { get; set; } public string name { get; set; } public string location { get; set; } public Int32 qty { get; set; } public List<Data2> bins { get; set; } } public class Data2 { public string code { get; set; } public string name { get; set; } public string location { get; set; } public Int32 qty { get; set; } }

Main函数：

class Program { static void Main(string[] args) { string json = "{success:true,data:{id:100001,code:\"JTL-Z38005\",name:\"奥迪三轮毂\",location:\"A-202\",qty:100,bins:[{code:\"JTL-Z38001\",name:\"奥迪三轮毂\",location:\"A-001\",qty:100},{ code:\"JTL-Z38002\",name:\"奥迪三轮毂\",location:\"A-002\",qty:100}]}}"; Data data = JsonConvertDeserializeObject<Data>(json); foreach (var item in datadatabins) { //输出：JTL-Z38001、JTL-Z38002，其它类似 ConsoleWriteLine(itemcode); } } }

JSON字符串2：

{\"success\":true,\"data\":{\"name\":\"张三\",\"moulds\":{\"stockImport\":true,\"stockExport\":true,\"justifyLocation\":true,\"justifyBin\":false,\"binRelease\":false}}}

在控制台应用程序下的完整代码：

namespace ConsoleApplication1 { class Program { static void Main(string[] args) { string json = "{\"success\":true,\"data\":{\"name\":\"张三\",\"moulds\":{\"stockImport\":true,\"stockExport\":true,\"justifyLocation\":true,\"justifyBin\":false,\"binRelease\":false}}}"; Data data = JsonConvertDeserializeObject<Data>(json); ConsoleWriteLine(datadatamouldsbinRelease);//输出False } } public class Data { public Boolean success { get; set; } public Data1 data { get; set; } } public class Data1 { public string name { get; set; } public Data2 moulds { get; set; } } public class Data2 { public Boolean stockImport { get; set; } public Boolean stockExport { get; set; } public Boolean justifyLocation { get; set; } public Boolean justifyBin { get; set; } public Boolean binRelease { get; set; } } }

JSON字符串3：

{ "success": true, "data": { "id": 100001, "bin": "JIT-3JS-2K", "targetBin": "JIT-3JS-3K", "batchs": [ "B20140101", "B20140102" ] } }

他的问题主要是不知道batchs这里怎么处理，其实很简单就是一个数组而已。

完整代码如下：

namespace ConsoleApplication1 { class Program { static void Main(string[] args) { string json = "{\"success\": true,\"data\": {\"id\": 100001,\"bin\": \"JIT-3JS-2K\",\"targetBin\": \"JIT-3JS-3K\",\"batchs\": [\"B20140101\",\"B20140102\"]}}"; Data data = JsonConvertDeserializeObject<Data>(json); foreach (var item in datadatabatchs) { ConsoleWriteLine(item);//输出：B20140101、B20140102 } } } public class Data { public Boolean success { get; set; } public Data1 data { get; set; } } public class Data1 { public Int32 id { get; set; } public string bin { get; set; } public string targetBin { get; set; } public string[] batchs { get; set; } } }

除了上述返回类的实体对象做法之外，JSONNET还提供了JObject类，可以取自己指定节点的内容。

比如：

namespace ConsoleApplication1 { class Program { static void Main(string[] args) { string j = "{success:true,data:{ bin:{code:\"JTL-Z38001\",name:\"奥迪三轮毂\",location:\"A-001\",qty:100}}}"; JObject jo = (JObject)JsonConvertDeserializeObject(j); ConsoleWriteLine(jo); } } public class Data { public Boolean success { get; set; } public Data1 data { get; set; } } public class Data1 { public Data2 bin { get; set; } } public class Data2 { public string code { get; set; } public string name { get; set; } public string location { get; set; } public Int32 qty { get; set; } } }

直接运行，返回结果如下：

如果输出内容修改为：

ConsoleWriteLine(jo["data"]);

继续取bin节点。

ConsoleWriteLine(jo["data"]["bin"]);

最后我们取其中name对应的value。

ConsoleWriteLine(jo["data"]["bin"]["name"]);

一步一步的获取了JSON字符串对应的Value。

——————————————————————————————————————————————————

群里有人提出一个问题，比如我要生成如下的JSON字符串，该如何处理呢？

{ "id": 1, "value": "cate", "child": [ { "id": 1, "value": "cate", "child": [ ] }, { "id": 1, "value": "cate", "child": [ { "id": 2, "value": "cate2", "child": [ { "id": 3, "value": "cate3", "child": [ ] } ] } ] } ] }

通过观察我们会发现，其实规律比较好找，就是包含id、value、child这样的属性，child又包含id、value、child这样的属性，可以无限循环下去，是个典型的树形结构。

完整的代码如下：

namespace ConsoleApplication1 { class Program { static void Main(string[] args) { Data data = new Data(); dataid = 1; datavalue = "cate"; datachild = new List<Data>() { new Data(){ id=1,value="cate",child=new List<Data>(){}} , new Data(){ id=1,value="cate",child=new List<Data>() { new Data() { id=2, value="cate2" , child = new List<Data>() { new Data() { id = 3, value = "cate3", child = new List<Data>(){}, } }, } }} , }; //序列化为json字符串 string json = JsonConvertSerializeObject(data); ConsoleWriteLine(json); //反序列化为对象 Data jsonData = JsonConvertDeserializeObject<Data>(json); } } public class Data { public int id { get; set; } public string value { get; set; } public List<Data> child { get; set; } } }

我们验证一下生成的结果：

JObject jo = (JObject)JsonConvertDeserializeObject(json); ConsoleWriteLine(jo);

再来一个复杂点的JSON结构：

[ { "downList": [], "line": { "Id": -1, "Name": "admin", "icCard": "1" }, "upList": [ { "endTime": "18:10", "startTime": "06:40", "sId": 385, "sType": "38" }, { "endTime": "18:10", "startTime": "06:40", "sId": 1036, "sType": "38" } ] }, { "downList": [], "line": { "Id": -1, "Name": "admin", "icCard": "1" }, "upList": [ { "endTime": "18:10", "startTime": "06:40", "sId": 385, "sType": "38" }, { "endTime": "18:10", "startTime": "06:40", "sId": 1036, "sType": "38" } ] } ]

namespace ConsoleApplication1 { class Program { static void Main(string[] args) { string jsonString = "[{\"downList\": [],\"line\": {\"Id\": -1,\"Name\": \"admin\",\"icCard\": \"1\"},\"upList\": [{\"endTime\": \"18:10\",\"startTime\": \"06:40\",\"sId\": 385,\"sType\": \"38\"},{\"endTime\": \"18:10\",\"startTime\": \"06:40\",\"sId\": 1036,\"sType\": \"38\"}]},{\"downList\": [],\"line\": {\"Id\": -1,\"Name\": \"admin\",\"icCard\": \"1\"},\"upList\": [{\"endTime\": \"18:10\",\"startTime\": \"06:40\",\"sId\": 385,\"sType\": \"38\"},{\"endTime\": \"18:10\",\"startTime\": \"06:40\",\"sId\": 1036,\"sType\": \"38\"}]}]"; Data[] datas = JsonConvertDeserializeObject<Data[]>(jsonString); foreach (Data data in datas) { downList[] downList = datadownList; line line = dataline; upList[] upLists = dataupList; //输出 ConsoleWriteLine(stringJoin(",", lineId, lineName, lineicCard)); foreach (upList upList in upLists) { ConsoleWriteLine(stringJoin(",", upListendTime, upListstartTime, upListsId, upListsType)); } ConsoleWriteLine("-----------------------------------------------"); } } } public class Data { public downList[] downList { get; set; } public line line { get; set; } public upList[] upList { get; set; } } public class downList { } public class line { public int Id { get; set; } public string Name { get; set; } public string icCard { get; set; } } public class upList { public string endTime { get; set; } public string startTime { get; set; } public int sId { get; set; } public string sType { get; set; } } }

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持易盾网络。