本文实例为大家介绍了几个可用的类，供大家参考，具体内容如下

1.SQLHelper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; } } } }}

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}

例如：

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"); }

以上就是本文的全部内容，希望对大家的学习有所帮助。