案例转自https://www.cnblogs.com/stonefeng/p/5679638.html
//主体基类
using System;
using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading.Tasks;namespace DecoratorModeDemo
{ abstract class PanCake { public string desc = ""; public abstract string getDesc(); public abstract double price(); }}
//主体：肉夹馍
using System;
using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading.Tasks;namespace DecoratorModeDemo
{ class Roujiamo:PanCake { public Roujiamo() { this.desc = "肉夹馍"; }public override string getDesc()
{ return desc; }public override double price()
{ return 6; }}
}
//主体手抓饼
using System;
using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading.Tasks;namespace DecoratorModeDemo
{ class TornCake:PanCake { public TornCake() { this.desc = "手抓饼"; }public override string getDesc()
{ return desc; }public override double price()
{ return 4; } }}
//装饰者基类
using System;
using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading.Tasks;namespace DecoratorModeDemo
{ abstract class Condiment:PanCake { public PanCake panCake; public Condiment(PanCake p) { panCake = p; }}
}
//装饰者煎蛋
using System;
using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading.Tasks;namespace DecoratorModeDemo
{ class FiredEgg:Condiment { public FiredEgg(PanCake pancake):base(pancake) { } public override string getDesc() { return panCake.getDesc()+",煎蛋"; } public override double price() { return this.panCake.price() + 2; } }}
//主函数
using System;
using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading.Tasks;namespace DecoratorModeDemo
{ class Program { static void Main(string[] args) { TornCake torncake = new TornCake(); Console.WriteLine(torncake.getDesc() + " ￥" +torncake.price().ToString());PanCake roujiamo = new Roujiamo();
roujiamo = new FiredEgg(roujiamo); roujiamo = new FiredEgg(roujiamo); Console.WriteLine(roujiamo.getDesc()+" ￥"+roujiamo.price()); Console.ReadLine(); } }}
运行结果
心得：装饰者派生自主体基类，继承了主体需要操作的对象。同时装饰者的成员对象中有主体，用以耦合主体。通过创建不同的装饰者派生类，重写主体类方法来实现对主体类的不同操作。
roujiamo = new FiredEgg(roujiamo)实际上roujiamo已经变成了煎蛋，只不过这个煎蛋的成员包含肉夹馍，返回的方法经重写已经用原肉夹馍处理过了。
最佳答案
报这个错是因为，提交了主键重复的数据，虽然未提交到数据库中
但是现在的EF上下文中已经包含了我提交的数据，下次在提交正确数据时，
原来添加到上下文中的数据依然还在。。如何处理这个问题呢？
using(var db = new .......())
{
db.save...........();
}
1、dbcontext 每次使用时重新new一个，不要使用单例模式，可以考虑单元模式。
2、EF 上下文被我设置成了静态的了
3、我也是Commit时SaveChanges() 方法报更新条目出错，
别人说是数据的id 重复，但我调试看了Add 的三个id 都没重复，
后来发现是Add对象的DateTime 类型的属性没有赋值。赋值之后就能保存到数据库了。
4、一次插入多行时，其中有一个重复（我创建了唯一复合索引），导致所有都插入失败，而且重新运行插入依然失败。这说明了公用一个上下文的坏处，
后来改用Using和cry catch。不出错就一次插入，出错就循环赋值中using多个上下文，保证不重复部分插入成功。
来源：https://q.cnblogs.com/q/44768/
一、C#默认四舍五入
1 Math.Round(45.367,2) //Returns 45.37
2 Math.Round(45.365,2) //Returns 45.36二、C#中的Round()不是我们中国人理解的四舍五入，是老外的四舍五入，是符合IEEE标准的四舍五入，具体是四舍六入，下面的才是符合中国人理解的四舍五入。
1 Math.Round(45.367,2,MidpointRounding.AwayFromZero); //Returns 45.37
2 Math.Round(45.365,2,MidpointRounding.AwayFromZero); //Returns 45.37
来源：https://www.cnblogs.com/xuliangxing/p/6585865.html
啥都不说先看图
一、 功能介绍
1. winform DataGridView样式代码可视化即时生成,所见即所得
2. 预置DataGridView样式代码方案
预置三种样式方案可在此基础上复制生成新的样式方案,
3. 样式方案删除自动备份
样式方案删除后自动改名为 样式方案文件名_bak_20151007-084328.dgvs 文件备份到程序启动目录下的backup文件夹内,需要恢复时移动到程序启动目录即可
4. 预览导入已生成样式方案
导入本软件生成的样式方案可以预览代码 样式,及属性设置
二、 使用方法:
1. 样式代码的使用方法
选择并复制要应用的样式代码
新建一个窗体拖入一个DataGridView控件
按F7转到代码视图
应用样式
注意:DataGridView要设置数据源,如没有数据则不会显示样式出来 以下是最终效果
2. 新建自定义样式代码
点击新建方案按钮
在右侧样式设置面板设置各种属性
注意:文本框直接输入格式如#ff0000格式的十六进制颜色值或者双击选择颜色值
3. 复制现有样式代码
可以在已有的样式方案基础上再做修改然后保存为新样式方案
在博问上看到一个提问“MSSQL如何将查询结果拼接成字符串” ，想了一下应该怎么实现呢，在c#等语言下好实现，但在sql里实现、还真没做过。
目标：想要在SQL中将查询的结果拼接为 '1','2','3','4','5'
分析：要进行拼接就要取得每行的值，想到了游标可以做到。于是有了下面的方法
select name from area
查询结果如下
办公楼
车间宿舍未知宜家厂综合楼解决方法：
declare @name varchar(50)
declare @result varchar(500)set @result=''--定义一个游标
declare user_cur cursor for select name from area
--打开游标open user_curwhile @@fetch_status=0begin--读取游标fetch next from user_cur into @name--print @nameset @result=@result+','''+@name+''''--print @Loginendclose user_cur--摧毁游标deallocate user_curprint @result
查询结果如下：
,'宜家厂','宿舍','车间','未知','办公楼','综合楼','综合楼'
//电商ID
private string EBusinessID = "1257164";//电商加密私钥，快递鸟提供，注意保管，不要泄漏private string AppKey = "63a33b7c-464c-4de6-b4a3-6e1fc19da51c";//请求urlprivate string ReqURL = "http://api.kdniao.cc/Ebusiness/EbusinessOrderHandle.aspx";/// <summary>
/// Json方式 查询订单物流轨迹/// </summary>/// <returns></returns>public string postkuaidi(string com, string nu){ Dictionary<string, string> list = new Dictionary<string, string>();#region 快递list.Add("邮政平邮", "YZPY");list.Add("邮政国内", "YZPY");list.Add("中国邮政", "YZPY");list.Add("申通快递", "STO");#endregion
string typeCom = "";foreach (var dc in list){ if (com == dc.Key){ typeCom = dc.Value;}}string requestData = "{OrderCode:'',ShipperCode:'" + typeCom + "','LogisticCode':'" + nu + "'}";Dictionary<string, string> param = new Dictionary<string, string>();
param.Add("RequestData", HttpUtility.UrlEncode(requestData, Encoding.UTF8));param.Add("EBusinessID", EBusinessID);param.Add("RequestType", "1002");string dataSign = encrypt(requestData, AppKey, "UTF-8");param.Add("DataSign", HttpUtility.UrlEncode(dataSign, Encoding.UTF8));param.Add("DataType", "2");string result = sendPost(ReqURL, param);
//根据公司业务处理返回的信息......
JObject jo = JObject.Parse(result);return jo.ToString();}
/// <summary>
/// Post方式提交数据，返回网页的源代码/// </summary>/// <param name="url">发送请求的 URL</param>/// <param name="param">请求的参数集合</param>/// <returns>远程资源的响应结果</returns>private string sendPost(string url, Dictionary<string, string> param){ string result = "";StringBuilder postData = new StringBuilder();if (param != null && param.Count > 0){ foreach (var p in param){ if (postData.Length > 0){ postData.Append("&");}postData.Append(p.Key);postData.Append("=");postData.Append(p.Value);}}byte[] byteData = Encoding.GetEncoding("UTF-8").GetBytes(postData.ToString());try{HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
request.ContentType = "application/x-www-form-urlencoded";request.Referer = url;request.Accept = "*/*";request.Timeout = 30 * 1000;request.UserAgent = "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; .NET CLR 2.0.50727; .NET CLR 3.0.04506.648; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729)";request.Method = "POST";request.ContentLength = byteData.Length;Stream stream = request.GetRequestStream();stream.Write(byteData, 0, byteData.Length);stream.Flush();stream.Close();HttpWebResponse response = (HttpWebResponse)request.GetResponse();Stream backStream = response.GetResponseStream();StreamReader sr = new StreamReader(backStream, Encoding.GetEncoding("UTF-8"));result = sr.ReadToEnd();sr.Close();backStream.Close();response.Close();request.Abort();}catch (Exception ex){ result = ex.Message;}return result;}///<summary>
///电商Sign签名///</summary>///<param name="content">内容</param>///<param name="keyValue">Appkey</param>///<param name="charset">URL编码 </param>///<returns>DataSign签名</returns>private string encrypt(String content, String keyValue, String charset){ if (keyValue != null){ return base64(MD5(content + keyValue, charset), charset);}return base64(MD5(content, charset), charset);}///<summary>
/// 字符串MD5加密///</summary>///<param name="str">要加密的字符串</param>///<param name="charset">编码方式</param>///<returns>密文</returns>private string MD5(string str, string charset){ byte[] buffer = System.Text.Encoding.GetEncoding(charset).GetBytes(str);try{ System.Security.Cryptography.MD5CryptoServiceProvider check;check = new System.Security.Cryptography.MD5CryptoServiceProvider();byte[] somme = check.ComputeHash(buffer);string ret = "";foreach (byte a in somme){ if (a < 16)ret += "0" + a.ToString("X");elseret += a.ToString("X");}return ret.ToLower();}catch{ throw;}}/// <summary>
/// base64编码/// </summary>/// <param name="str">内容</param>/// <param name="charset">编码方式</param>/// <returns></returns>private string base64(String str, String charset){ return Convert.ToBase64String(System.Text.Encoding.GetEncoding(charset).GetBytes(str));}
/// <summary>
/// SMTP发送邮件/// </summary>/// <param name="fromEmail">发送邮件地址</param>/// <param name="toEmail">收件箱</param>/// <param name="subject">邮箱主题</param>/// <param name="contentAttachment"></param>/// <param name="fromEmailPwd">发送邮件密码</param>/// <returns></returns> public static bool SendMailBySMTP(string fromEmail, string toEmail, string subject, Attachment contentAttachment,string fromEmailPwd){ bool rr = true;if (ConfigurationManager.AppSettings["CreditoEmailSwitch"].ToString() == "true"){ System.Net.Mail.MailMessage mail = new System.Net.Mail.MailMessage(fromEmail, toEmail); mail.SubjectEncoding = Encoding.UTF8;mail.Subject = subject;mail.IsBodyHtml = true; //是否允许内容为 HTML 格式mail.BodyEncoding = Encoding.UTF8;string emailContent = "邮件内容";mail.Body = emailContent;mail.Attachments.Add(contentAttachment); //添加一个附件int defaltFlag = 0;SmtpClient smtp = new SmtpClient("fastsmtp.qiye.163.com");//serviceFlag > 14 ? "smtp.qiye.163.com" : smtp.Port = 25;smtp.EnableSsl = true;smtp.Credentials = new NetworkCredential(fromEmail, fromEmailPwd); //SMTP 验证//smtp.DeliveryMethod = SmtpDeliveryMethod.PickupDirectoryFromIis;smtp.DeliveryMethod = SmtpDeliveryMethod.Network;try
{ smtp.Send(mail);}catch (Exception ex){ rr = false;SysLog.Write("发送邮件异常", ex.Message + "时间:" + DateTime.Now.ToString());}finally{ mail.Attachments.Dispose(); //邮件发送完毕，释放对附件的锁定}}else{ rr = false;}return rr;}
public static string GetPostString(string urladdress, string @params)
{ string returnValue = null;using (WebClient client = new WebClient()){ client.Headers.Add("Content-Type", "application/x-www-form-urlencoded");client.Encoding = Encoding.UTF8;returnValue = client.UploadString(urladdress, "POST", @params);}return returnValue;}-------------------------以上 为 与同事之间的接口查询-------------------------------------
由于使用 收费 第三方 屏蔽 可能有 免费 第三方。
private const string Cdkey = "8S*********************";密钥id
private const string Password = "151515******";密钥密码private const string BaseUrl = "http://hprpt******地址*";/// <summary>/// 发送及时短信/// </summary>/// <param name="phone"></param>/// <param name="content"></param>/// <returns></returns>public string SendSms(string phone, string content){ //UTF-8string Content = HttpUtility.UrlEncode(content.Trim(), System.Text.Encoding.GetEncoding("UTF-8"));phone = phone.Replace("\r\n", "").Trim();string sendurl = BaseUrl + "/sdkproxy/sendsms.action?cdkey=" + Cdkey + "&password=" + Password + "&phone=" + phone + "&message=" + Content;var resultstr = string.Empty;try{ var rst = (HttpWebRequest)WebRequest.Create(sendurl); //主要第一步using (var stream = rst.GetResponse().GetResponseStream())//第二步{ if (stream != null){ using (var reader = new StreamReader(stream, Encoding.GetEncoding("UTF-8")))//3{ resultstr = reader.ReadToEnd();//4}}}}catch (Exception ex){ throw;}return resultstr;}
private static string logPath = @"D:\LogS\Logs\";
public static string FloderPath
{ get{ return logPath;}set{ logPath = value;}}private static object lockHelper = new object();
//简单的写了一个页面public ActionResult Logtext()
{ return View();}//简单的写了一个页面入口提交文字
public ActionResult Add(string Text){ string textlog = Text;//写入Write("测试：", textlog);string fileName = "测试：" + "-" + DateTime.Now.ToString("yyyy_MM_dd") + ".log";//读取var str = Read(fileName, "utf-8");var Temp = new
{ nsuccess = false,message = "写入读取成功"};return Json(Temp);} /// <summary>/// 写日志/// </summary>/// <param name="LogType">日志类型</param>/// <param name="Strings">消息</param>public static bool Write(string LogType, string str){ try{ //string fileName = LogType + "-" + DateTime.Now.ToString("yyyy_MM_dd") + ".log";if (!System.IO.Directory.Exists(FloderPath)){ System.IO.Directory.CreateDirectory(FloderPath);}return Write(LogType, str, "utf-8");}catch{ return false;}}/// <summary>/// 写日志gb2312 UTF-8/// </summary>/// <param name="LogType">日志类型</param>/// <param name="str">消息</param>/// <param name="encoding">编码gb2312 UTF-8</param>public static bool Write(string LogType, string str, string encoding){ if (!System.IO.Directory.Exists(FloderPath)){ System.IO.Directory.CreateDirectory(FloderPath);}string fileName = LogType + "-" + DateTime.Now.ToString("yyyy_MM_dd") + ".log";bool _isTrue = false;lock (lockHelper){ System.IO.FileStream f = null;System.IO.StreamWriter f2 = null;try{ if (!System.IO.File.Exists(logPath + fileName)) { f = System.IO.File.Create(logPath + fileName); f.Close(); f.Dispose(); f = null; }f2 = new System.IO.StreamWriter(logPath + fileName, true, System.Text.Encoding.GetEncoding(encoding));f2.WriteLine("----------------------------------------header-------------------------------------");f2.WriteLine(str);f2.WriteLine("----------------------------------------footer-------------------------------------");_isTrue = true;}catch { }finally{ if (f != null) { f.Close(); f.Dispose(); f = null; }if (f2 != null) { f2.Close(); f2.Dispose(); f2 = null; }}}return _isTrue;} /// <summary>/// 读取文件中的内容/// </summary>/// <param name="fileName">文件</param>/// <param name="encoding">编码gb2312 UTF-8</param>/// <returns>ArrayList</returns>public static ArrayList Read(string fileName, string encoding){ string lineText = null; ArrayList txtTextArr = new ArrayList();if (!System.IO.File.Exists(FloderPath + fileName)) { txtTextArr = null; return txtTextArr; }lock (lockHelper)
{ StreamReader reader = encoding.Equals("") ? new StreamReader(FloderPath + fileName) : new StreamReader(FloderPath + fileName, System.Text.Encoding.GetEncoding(encoding));while ((lineText = reader.ReadLine()) != null){ txtTextArr.Add(lineText);}reader.Close();
reader.Dispose();}return txtTextArr;}