分享C#中几个可用的类

using system;
using system.collections.generic;
using system.linq;
using system.text;
using system.data.sqlclient;
using system.data;

using system.configuration;
namespace myschool.dal
{
 public static class sqlhelper
 {
 //用静态的方法调用的时候不用创建sqlhelper的实例
 //execetenonquery
 // public static string constr = "server=happypig\\sqlmodel;database=shooltest;uid=sa;";
 public static string constr = configurationmanager.connectionstrings["constr"].connectionstring;
 public static int id;
 /// <summary>
 /// 执行nonquery命令
 /// </summary>
 /// <param name="cmdtxt"></param>
 /// <param name="parames"></param>
 /// <returns></returns>
 public static int executenonquery(string cmdtxt, params sqlparameter[] parames)
 {
 return executenonquery(cmdtxt, commandtype.text, parames);
 }
 //可以使用存储过程的executenonquery
 public static int executenonquery(string cmdtxt, commandtype cmdtype, params sqlparameter[] parames)
 {
 //判断脚本是否为空 ，直接返回0
 if (string.isnullorempty(cmdtxt))
 {
 return 0;
 }
 using (sqlconnection con = new sqlconnection(constr))
 {
 using (sqlcommand cmd = new sqlcommand(cmdtxt, con))
 {
  if (parames != null)
  {
  cmd.commandtype = cmdtype;
  cmd.parameters.addrange(parames);
  }
  con.open();
  return cmd.executenonquery();
 }
 }
 }
 public static sqldatareader executedatareader(string cmdtxt, params sqlparameter[] parames)
 {
 return executedatareader(cmdtxt, commandtype.text, parames);
 }
 //sqldatareader存储过程方法
 public static sqldatareader executedatareader(string cmdtxt, commandtype cmdtype, params sqlparameter[] parames)
 {
 if (string.isnullorempty(cmdtxt))
 {
 return null;
 }
 sqlconnection con = new sqlconnection(constr);

 using (sqlcommand cmd = new sqlcommand(cmdtxt, con))
 {
 cmd.commandtype = cmdtype;
 if (parames != null)
 {
  
  cmd.parameters.addrange(parames);
 }
 con.open();
 //把reader的行为加进来。当reader释放资源的时候，con也被一块关闭
 return cmd.executereader(system.data.commandbehavior.closeconnection);
 }

 }
 public static datatable executedatatable(string sql, params sqlparameter[] parames)
 {
 return executedatatable(sql, commandtype.text, parames);
 }
 //调用存储过程的类，关于(executedatatable)
 public static datatable executedatatable(string sql, commandtype cmdtype, params sqlparameter[] parames)
 {
 if (string.isnullorempty(sql))
 {
 return null;
 }
 datatable dt = new datatable();
 using (sqldataadapter da = new sqldataadapter(sql, constr))
 {
 da.selectcommand.commandtype = cmdtype;
 if (parames != null)
 {
  da.selectcommand.parameters.addrange(parames);
 }
 da.fill(dt);
 return dt;
 }
 }
 
 /// <summary>
 /// executescalar
 /// </summary>
 /// <param name="cmdtxt">第一个参数，sqlserver语句</param>
 /// <param name="parames">第二个参数，传递0个或者多个参数</param>
 /// <returns></returns>
 public static object executescalar(string cmdtxt, params sqlparameter[] parames)
 {
 return executescalar(cmdtxt, commandtype.text, parames);
 } 
 //可使用存储过程的executescalar
 public static object executescalar(string cmdtxt, commandtype cmdtype, params sqlparameter[] parames)
 {
 if (string.isnullorempty(cmdtxt))
 {
 return null;
 }
 using (sqlconnection con = new sqlconnection(constr))
 {
 using (sqlcommand cmd = new sqlcommand(cmdtxt, con))
 {
  cmd.commandtype = cmdtype;
  if (parames != null)
  {
  cmd.parameters.addrange(parames);
  }
  con.open();
 return cmd.executescalar();
 }
 }
 
 }
 //调用存储过程的dbhelper类（关于execeutscalar,包含事务,只能处理int类型，返回错误号）
 public static object executescalar(string cmdtxt, commandtype cmdtype,sqltransaction sqltran, params sqlparameter[] parames)
 {
 if (string.isnullorempty(cmdtxt))
 {
 return 0;
 }
 using (sqlconnection con = new sqlconnection(constr))
 {
 int sum = 0;
 using (sqlcommand cmd = new sqlcommand(cmdtxt, con))
 {
  cmd.commandtype=cmdtype;
  if (parames != null)
  {
  cmd.parameters.addrange(parames);
  }
  con.open();
  sqltran = con.begintransaction();
  try
  {
  cmd.transaction = sqltran;
  sum=convert.toint32( cmd.executescalar());
  sqltran.commit();
  }
  catch (sqlexception ex)
  {
  sqltran.rollback();
  }
  return sum;
 }
 }
 }
 }
}

 //以返回表的方式加载下拉框
 public datatable loadcombox()
 {
 string sql = "select * from grade";
 datatable dt = sqlhelper.executedatatable(sql);
 return dt;
 }

using system;
using system.collections.generic;
using system.data;
using system.data.sqlclient;
using system.linq;
using system.reflection;
using system.text;
using system.threading.tasks;

namespace myschool.dal
{
 public class mytool
 {
 /// <summary>
 /// datasettolist
 /// </summary>
 /// <typeparam name="t">转换类型</typeparam>
 /// <param name="dataset">数据源</param>
 /// <param name="tableindex">需要转换表的索引</param>
 /// <returns></returns>
 public list<t> datatabletolist<t>(datatable dt)
 {
 //确认参数有效
 if (dt == null )
 return null;
 list<t> list = new list<t>();

 for (int i = 0; i < dt.rows.count; i++)
 {
 //创建泛型对象
 t _t = activator.createinstance<t>();
 //获取对象所有属性
 propertyinfo[] propertyinfo = _t.gettype().getproperties();
 for (int j = 0; j < dt.columns.count; j++)
 {
  foreach (propertyinfo info in propertyinfo)
  {
  //属性名称和列名相同时赋值
  if (dt.columns[j].columnname.toupper().equals(info.name.toupper()))
  {
  if (dt.rows[i][j] != dbnull.value)
  {
  info.setvalue(_t, dt.rows[i][j], null);
  }
  else
  {
  info.setvalue(_t, null, null);
  }
  break;
  }
  }
 }
 list.add(_t);
 }
 return list;
 }
 }
}

 public list<grade> loadcombox2() 
 {
 string sql = "select * from grade";
 datatable dt = sqlhelper.executedatatable(sql);
 //方法一：
 foreach (datarow row in dt.rows)
 {
  //每一个row代表表中的一行,所以一行对应一个年级对象
  grade grade = new grade();
  grade.gradeid = convert.toint32(row["gradeid"]);
  grade.gradename = row["gradename"].tostring();
  list.add(grade);
 }

 //方法二：(使用mytool类)
 mytool tool=new mytool();
 list = tool.datatabletolist<grade>(dt);
 return list;
 }

using system;
using system.collections.generic;
using system.text;
using system.windows.forms;

/// <summary>
/// 消息条回调函数委托
/// </summary>
public delegate void dgmsgdiv();
 /// <summary>
 /// 消息条类 带timer计时
 /// </summary>
public class msgdiv : system.windows.forms.label
{
 private timer timerlable = new timer();
 /// <summary>
 /// 消息回调 委托对象
 /// </summary>
 private dgmsgdiv dgcallback = null;

 #region 计时器
 /// <summary>
 /// 计时器
 /// </summary>
 public timer timermsg
 {
 get { return timerlable; }
 set { timerlable = value; }
 } 
 #endregion

 #region msgdiv构造函数
 /// <summary>
 /// msgdiv构造函数
 /// </summary>
 public msgdiv()
 {
 initallmsgdiv(7, 7);
 }

 /// <summary>
 /// msgdiv构造函数
 /// </summary>
 /// <param name="x">定位x轴坐标</param>
 /// <param name="y">定位y轴坐标</param>
 public msgdiv(int x, int y)
 {
 initallmsgdiv(x, y);
 }
 #endregion

 #region 初始化消息条
 /// <summary>
 /// 初始化消息条
 /// </summary>
 private void initallmsgdiv(int x, int y)
 {
 this.autosize = true;
 this.backcolor = system.drawing.color.fromargb(((int)(((byte)(255)))), ((int)(((byte)(255)))), ((int)(((byte)(192)))));
 this.borderstyle = system.windows.forms.borderstyle.fixedsingle;
 //this.contextmenustrip = this.cmslist;
 this.font = new system.drawing.font("宋体", 11f, system.drawing.fontstyle.bold, system.drawing.graphicsunit.point, ((byte)(134)));
 this.forecolor = system.drawing.color.red;
 this.location = new system.drawing.point(x, y);
 this.maximumsize = new system.drawing.size(980, 525);
 this.name = "msgdiv";
 this.padding = new system.windows.forms.padding(7);
 this.size = new system.drawing.size(71, 31);
 this.tabindex = 1;
 this.text = "消息条";
 this.visible = false;
 //给委托添加事件
 this.doubleclick += new system.eventhandler(this.msgdiv_doubleclick);
 this.mouseleave += new system.eventhandler(this.msgdiv_mouseleave);
 this.mousehover += new system.eventhandler(this.msgdiv_mousehover);
 this.timerlable.interval = 1000;
 this.timerlable.tick += new system.eventhandler(this.timerlable_tick);
 }
 #endregion

 #region 将消息条添加到指定容器上
 /// <summary>
 /// 将消息条添加到指定容器上form
 /// </summary>
 /// <param name="form"></param>
 public void addtocontrol(form form)
 {
 form.controls.add(this);
 }
 /// <summary>
 /// 将消息条添加到指定容器上groupbox
 /// </summary>
 /// <param name="form"></param>
 public void addtocontrol(groupbox groupbox)
 {
 groupbox.controls.add(this);
 }
 /// <summary>
 /// 将消息条添加到指定容器上panel
 /// </summary>
 /// <param name="form"></param>
 public void addtocontrol(panel panel)
 {
 panel.controls.add(this);
 }
 #endregion

 //---------------------------------------------------------------------------
 #region 消息显示 的相关参数们 hiddenclick，countnumber，constcountnumber
 /// <summary>
 /// 当前显示了多久的秒钟数
 /// </summary>
 int hiddenclick = 0;
 /// <summary>
 /// 要显示多久的秒钟数 可变参数
 /// </summary>
 int countnumber = 3;
 /// <summary>
 /// 要显示多久的秒钟数 固定参数
 /// </summary>
 int constcountnumber = 3; 
 #endregion

 #region 计时器 显示countnumber秒钟后自动隐藏div -timerlable_tick(object sender, eventargs e)
 private void timerlable_tick(object sender, eventargs e)
 {
 if (hiddenclick > countnumber - 2)
 {
 msgdivhidden();
 }
 else
 {
 hiddenclick++;
 //remaincount();
 }
 } 
 #endregion

 #region 隐藏消息框 并停止计时 +void msgdivhidden()
 /// <summary>
 /// 隐藏消息框 并停止计时
 /// </summary>
 public void msgdivhidden()
 {
 this.text = "";
 this.visible = false;
 this.hiddenclick = 0;
 //this.tslblremainsecond.text = "";
 if (this.timerlable.enabled == true)
 this.timerlable.stop();

 //调用 委托 然后清空委托
 if (dgcallback != null && dgcallback.getinvocationlist().length > 0)
 {
 dgcallback();
 dgcallback -= dgcallback;
 }
 } 
 #endregion

 #region 在消息框中显示消息字符串 +void msgdivshow(string msg)
 /// <summary>
 /// 在消息框中显示消息字符串
 /// </summary>
 /// <param name="msg">要显示的字符串</param>
 public void msgdivshow(string msg)
 {
 this.text = msg;
 this.visible = true;
 this.countnumber = constcountnumber;//默认设置显示秒数为10;
 this.hiddenclick = 0;//重置倒数描述
 this.timerlable.start();
 } 
 #endregion

 #region 在消息框中显示消息字符串 并在消息消失时 调用回调函数 +void msgdivshow(string msg, dgmsgdiv callback)
 /// <summary>
 /// 在消息框中显示消息字符串 并在消息消失时 调用回调函数
 /// </summary>
 /// <param name="msg">要显示的字符串</param>
 /// <param name="callback">回调函数</param>
 public void msgdivshow(string msg, dgmsgdiv callback)
 {
 msgdivshow(msg);
 dgcallback = callback;
 }
 #endregion

 #region 在消息框中显示消息字符串 并在指定时间消息消失时 调用回调函数 +void msgdivshow(string msg, int seconds, dgmsgdiv callback)
 /// <summary>
 /// 在消息框中显示消息字符串 并在消息消失时 调用回调函数
 /// </summary>
 /// <param name="msg">要显示的字符串</param>
 /// <param name="seconds">消息显示时间</param>
 /// <param name="callback">回调函数</param>
 public void msgdivshow(string msg, int seconds, dgmsgdiv callback)
 {
 msgdivshow(msg, seconds);
 dgcallback = callback;
 } 
 #endregion

 #region 在消息框中显示消息字符串，并指定消息框显示秒数 +void msgdivshow(string msg, int seconds)
 /// <summary>
 /// 在消息框中显示消息字符串，并指定消息框显示秒数
 /// </summary>
 /// <param name="msg">要显示的字符串</param>
 /// <param name="seconds">消息框显示秒数</param>
 public void msgdivshow(string msg, int seconds)
 {
 this.text = msg;
 this.visible = true;
 this.countnumber = seconds;
 this.hiddenclick = 0;//重置倒数描述
 this.timerlable.start();
 } 
 #endregion

 //---------------------------------------------------------------------------
 #region 事件们～～～！ msgdiv_mousehover，msgdiv_mouseleave，msgdiv_doubleclick
 //当鼠标停留在div上时 停止计时
 private void msgdiv_mousehover(object sender, eventargs e)
 {
 if (this.timerlable.enabled == true)
 this.timerlable.stop();
 }
 //当鼠标从div上移开时 继续及时
 private void msgdiv_mouseleave(object sender, eventargs e)
 {
 //当消息框正在显示、回复框没显示、计时器正停止的时候，重新启动计时器
 if (this.visible == true && this.timerlable.enabled == false)
 this.timerlable.start();
 }
 //双击消息框时关闭消息框
 private void msgdiv_doubleclick(object sender, eventargs e)
 {
 msgdivhidden();
 } 
 #endregion

}

 private void form1_load(object sender, eventargs e)
 {
 //首先显示“呵呵”，3秒后 调用test方法消息框显示“哈哈”
 msgdiv1.msgdivshow("呵呵",3,test);
 }

 public void test()
 {
 messagebox.show("哈哈");
 }