例如：
//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;
}
2.MyTool类（DataTable转List<>）
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;
}
}
}
例如：
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;
}
3.DGMsgDiv类（可生成自己的控件）
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
}
