C#

  string appPath = AppDomain.CurrentDomain.BaseDirectory + "NCDB.db";  //相对路径
!string.IsNullOrEmpty(txtCostCenterCode.Text)

A.托管代码是一种中间语言，运行在CLR上。
A.非托管代码被编译为机器码，运行在机器上。

B.托管代码独立与平台和语言，能更好的实现不同语言平台之间的兼容。
B.非托管代码依赖于平台和语言。

C.托管代码可是享受CLR提供的服务（安全检测，垃圾回收，）不需要自己完成这些操作
C.非托管代码需要自己提供安全检测，垃圾回收等操作

C:ProgramDataMicrosoft Visual Studio10.0

dt.Rows.Count   判断datatable是否含有数据
yyyy-MM-dd HH:mm:ss   转换成时间格式，注意各字母大小写

 public List<udt_mm_ComReceiveMat_Detailed> DQueryNow(string strWhere, int PageID)
        {
            StringBuilder strSql = new StringBuilder();
            strSql.Append("Select * From  udt_mm_ComReceiveMat_Detailed AS D inner join ( select Key_ID,WF_Config_ID from udt_mm_WFCurrent where PU_ID between 1007 and 1009) AS T ON D.GID=T.Key_ID ");
            strSql.Append("where 1=1 and T.WF_Config_ID IN( select ID from udt_mm_WFConfigure where Menu_Id=" + PageID + ") " + strWhere + " ");
            var dt = DBFactory.Default.QuerySql(strSql.ToString()).Dataset.Tables[0];
            if (dt.Rows.Count == 0)
                return new List<udt_mm_ComReceiveMat_Detailed>();
            else
                return EntityBase.ToList<udt_mm_ComReceiveMat_Detailed>(DBFactory.Default.QuerySql(strSql.ToString()).Dataset.Tables[0]);
        }

 

        public udt_mm_WFCurrent QueryNowStep(string strWhere)
        {
            try
            {
                StringBuilder strSql = new StringBuilder();
                strSql.Append("Select ");
                strSql.Append(" Key_ID,PU_ID,WF_Config_ID ");
                strSql.Append(" From  udt_mm_WFCurrent ");
                strSql.Append("where 1=1 " + strWhere);
                var dt = DBFactory.Default.QuerySql(strSql.ToString()).Dataset.Tables[0];
                if (dt.Rows.Count == 0)
                    return new udt_mm_WFCurrent();
                else
                    return EntityBase.ToModel<udt_mm_WFCurrent>(dt.Rows[0]);
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }

 

将List 类型转换成DataTable
   public static DataTable ToDataTable(IList list)
        {

            DataTable result = new DataTable();
            if (list.Count > 0)
            {
                PropertyInfo[] properts = list[0].GetType().GetProperties();
                foreach (PropertyInfo pi in properts)
                {
                    result.Columns.Add(pi.Name, pi.PropertyType);
                }
                for (int i = 0; i < list.Count; i++)
                {
                    ArrayList tempList = new ArrayList();
                    foreach (PropertyInfo pi in properts)
                    {
                        object obj = pi.GetValue(list[i], null);
                        tempList.Add(obj);
                        object[] array = tempList.ToArray();
                        result.LoadDataRow(array, true);
                    }
                }
            }
            return result;
        }

查看一个函数执行所需的时间
using System.Diagnostics;

   Stopwatch watch = new Stopwatch();
                    watch.Start();
Funcation
                    watch.Stop();
                    string time = watch.ElapsedMilliseconds.ToString();
                    MsgBox.Show(time);

OR
     //DateTime now = DateTime.Now;
     //MessageBox.Show("初始化服务！" + (DateTime.Now - now).TotalSeconds);

            

比较两个时间大小 
                DateTime t1 = Convert.ToDateTime(dpBegin.SelectedDate);
                DateTime t2 = Convert.ToDateTime(dpEnd.SelectedDate);
                int compNum = DateTime.Compare(t1, t2);  //compNum==0时间相等
                if (compNum > 0)
                {
                    MsgBox.Show("开始时间不能大于结束时间");
                    return;
                }

Camel法则:单词中，首单词的首字母小写，其余每个单词的首字母大写，多用于变量
Pascal法则：每个单词的首字母都大写，多用于类或着方法

换行
var  声明的时候必须赋值

 public string ShowStandardPrice
        {
            get
            {
                return StandardPrice.ToString("F4"); //显示decimal类型的字段位数
            }
        }

property.PropertyType.IsGenericType   判断当前的值是否为泛型类型