ListBox控件的使用： 1）控件属性 Items SelectedItems SelectioModes 2）数据绑定 DataSoure DisplayMember ValueMenber 3)实例 下面开始一一说明上面的ListBox控件的使用。 首先来说控件的属性， (1)Items：使用此属性获取列表控件项的属性。此属性可用于确定列表控件中的选定项。添加items时既可以设计时静态添加，也可以在代码中动态添加。如果不想显示设计时添加的items，可以在代码中添加this.listBox1.Items.Clear();只显示...
并且有一些初始化语句List<People> PeopleList = new List<People>(); PeopleList.Add(new People() { Name = "Haocheng Wu", Age = 24 }); PeopleList.Add(new People() { Name = "Haocheng Wu", Age = 25 }); PeopleList.Add(new People() { Name = "James Wu", Age = 23 });你就可以采用下面类似于SQL语句的方法进行select List<string> SubPeopleNameList1 = (from people in PeopleListwhere people.Name == "Haocheng Wu" &&...
/// <summary>2 /// Sqlbulkcopies the specified SMS.批量插入到数据库3 /// </summary>4 /// <param name="data">list类型数据.</param>5 /// <param name="sqlconn">数据库连接字符串.</param>6 private void SqlbulkcopyPipeLines(List<CPipe> data, SqlConnection sqlconn, string prjId, string modid)7 {8 #region 待处理数据初始化处理9 List<Pr...
ListViewItem listViewItem=new ListViewItem(); listViewItem.SubItems[0].Text=""11111;//第一行第一例的值 listViewItem.SubItems.Add("222");///listViewItem.SubItems.Add("222");///以此类推ListView1.Items.Add(listViewItem); 三、Access中时间段查询的SQL语句书写规范（采用dateTimePick控件） 注意：# 是必须要加的string sql=select * from tableName where timeField between #"+dateTimePick1.value.ToString...
}).ToList();正确的答案（MySql）： var result = (from si in model.table group si by si.NumCores into grp orderby grp.Key select new CoreCount { Cores = grp.FirstOrDefault().NumCores, Count = grp.Count() }).ToList();以上在MySQL亲测有效，SQL server没有测试。。。C# linq group by 异常 -----MySqlException: Unknown column GroupBy1.K1 in field list标签：lis 答案 cores orderby mod sele mode m...
var sql = @"update [TABLE] WITH (ROWLOCK)SET 匹配方式 = {0} where ID in({1})"; //lissqls 是你要分组的泛型集合var GroupList = lissqls.GroupBy(x => x.MatchType).Select(x => new{ MatchType = x.Key, ItemIDLis = x.ToList() }); //存储更新语句 List<string> update_bill_sql = new List<string>();foreach (var item in GroupList){List<int> itemids = new List<int>();foreach (var itemID in item.ItemIDLis){itemi...
调用方法public static void examInviteByUserCode(string UserAD, List<string> paperIds){try{string sign = lightcloudsign();string factoryCode = ConfigurationManager.AppSettings["factoryCode"].ToString();string url = string.Format("https://api2.baidu.com/site/api/o?factoryCode={0}&sign={1}", factoryCode, sign);List<string> UserList = new List<string>();UserList.Add(UserAD.ToLower());foreach (var pape...
https://zhidao.baidu.com/question/681553612286124812.html 如果有类A和类B都继承了类C，类A已经存入到集合中了，那么此时用该方法判断类B，是会返回true还是false? 你的类和List如何定义的？ 我测试是返回false，定义如下： public class C { } public class A:C { } public class B:C { } private void button1_Click(object sender,EventArgs e) { A a=new A(); B b=new B(); C c=new C(); List lst=new List(); lst.Add(a); ...
服务端代码 using System; using System.Collections.Generic; using System.Linq; using System.Net; using System.Text; using System.Threading.Tasks;namespace HttpListener实验 {class Program{static HttpListener httpobj;static void Main(string[] args){//提供一个简单的、可通过编程方式控制的 HTTP 协议侦听器。此类不能被继承。httpobj = new HttpListener();//定义url及端口号，通常设置为配置文件httpobj.Prefixes...
//列求和 datatable.AsEnumerable().Sum(c => (ConvertEx.ToDecimal(c["列名"]))).ToString(); //list去重 strlist = strlist.Where((x, i) => strlist.FindIndex(z => z == x) == i).ToList(); //datatable某一列转list List<string>strlist= dtlist.AsEnumerable().Select(t => t.Field<string>("crm_name")).ToList(); //列反序 strlist.Reverse();
List是线程不安全的，通过一个数组存储数据，当容量达到数组上限时，创建一个新数组，因此存在线程安全问题 SafeList是在做增删改操作时返回一个新的ReadonlyList，所以不存在线程安全问题 /// <summary>/// SafeList is mutable, but it uses immutable data structures to minimize the need for locking./// The provided manipulation /// Exposes a immutable list. Changes are made by copying the lists./// SafeList is /...
string strUrl = ConfigurationManager.AppSettings["SiteUrl"]; string strWebUrl = ConfigurationManager.AppSettings["WebUrl"]; string strListName = ConfigurationManager.AppSettings["ListName"]; string strFieldName = ConfigurationManager.AppSettings["FieldName"];Microsoft.SharePoint.SPSecurity.RunWithElevatedPrivileges(delegate (){using (SPSite site = new SPSite(strUrl)){using (SPWeb web = site.OpenWe...
/// <summary>/// List集合转DataTable/// </summary>/// <typeparam name="T">实体类型</typeparam>/// <param name="list">传入集合</param>/// <returns>返回datatable结果</returns>public static DataTable ListToTable<T>(List<T> list){Type tp = typeof(T);PropertyInfo[] proInfos = tp.GetProperties();DataTable dt = new DataTable();foreach (var item in proInfos){dt.Columns.Add(item.Name, item.PropertyType); /...
公式：List.Skip((pagecount-1)*pagesize).Take(pagesize).ToList() pagecount:页码 pagesize:每页数据量 举个栗子： 前端点击页码 4，每页有50条数据：List.Skip((4-1)*50).Take(50).ToList() 解惑地址：https://blog.csdn.net/swarb/article/details/11165441
定义简单单链表结构 public class ListNode{public int val;public ListNode next;public ListNode(int val = 0, ListNode next = null){this.val = val;this.next = next;}}List转换为单链表，单链表转换为List的转换类 public class ListListNodeConversion{#region List集合转换为ListNodepublic static ListNode ListToListNode(List<int> list){if(list == null){return null;}ListNode head = null, tail = null;forea...