conn1.cs

一个简单的文件发布系统 用.net实现

using System;
using System.Data;
using System.Data.OleDb;
using System.Text;
using System.Web;

namespace news
{
	/// <summary>
	/// conn 的摘要说明。
	/// </summary>
	public class connection
	{
		public connection()
		{
			//
			// TODO: 在此处添加构造函数逻辑
			//
		}
		//配置数据库连接字符串
		public static string connstr="Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + HttpContext.Current.Server.MapPath("..\\DataBase\\#news.mdb");


		#region  执行SQL语句，返回SqlDataReader
		public OleDbDataReader Reader(string sql)
		{
			
			OleDbConnection conn = new OleDbConnection(connection.connstr);
			OleDbCommand comm = new OleDbCommand(sql,conn);
			OleDbDataReader dr = null;
			conn.Open();
			try
			{
				dr=comm.ExecuteReader(CommandBehavior.CloseConnection);
			}
			catch
			{
				//dr.Close();
				//comm.Dispose();
				conn.Close();
				throw;
			}
			return dr;
		}
		#endregion
		
		#region  执行SQL语句，返回DataAdapter
		public OleDbDataAdapter GetDataAdapter(string sql)
		{
			OleDbConnection conn = new OleDbConnection(connection.connstr);
			OleDbDataAdapter da = new OleDbDataAdapter(sql,conn);
			return da;		
		}
		#endregion
		
		#region  执行SQL语句，返回DataSet
		public DataSet GetDataSet(string sql,string tablename)
		{
			OleDbConnection conn = new OleDbConnection(connection.connstr);
			OleDbDataAdapter da = new OleDbDataAdapter(sql,conn);
			conn.Open();
			DataSet ds = new DataSet();
			try
			{
				da.Fill(ds,tablename);
			}
			catch
			{
				throw;
			}
			finally
			{
				conn.Close();
				conn.Dispose();
				da.Dispose();
			}
			return ds;
		}
		#endregion

		#region  执行SQL语句，进行数据库SQL语句执行操作，返回BOOL值
		public bool ExecuteSql(string sql)
		{
			OleDbConnection conn = new OleDbConnection(connection.connstr);
			OleDbCommand comm = new OleDbCommand(sql,conn);
			try
			{
				conn.Open();
				comm.ExecuteNonQuery();
				return true;
			}
			catch
			{
				return false;
			}
			finally
			{
				comm.Dispose();
				conn.Close();
				conn.Dispose();
			}
		}
		#endregion
		
		#region  执行SQL语句，返回指定数据表中的最大cindex值(不带SORT)
		public int Getcindex(string tablename)
		{
			OleDbConnection conn = new OleDbConnection(connection.connstr);
			string commstr = "select max(cindex) from " + tablename ;
			OleDbCommand comm= new OleDbCommand(commstr,conn);
			try
			{
				conn.Open();
				int maxcindex = Convert.ToInt32(comm.ExecuteScalar());
				return maxcindex;
			}
			catch
			{
				return 0;
			}
			finally
			{
				conn.Close();
				conn.Dispose();
				comm.Dispose();
			}
		}
		#endregion

		#region  执行SQL语句，返回指定数据表中的最大cindex值(带SORT)
		public int Getsortcindex(string tablename,string columnname,object sort)
		{
			OleDbConnection conn = new OleDbConnection(connection.connstr);
			string commstr = "select max(cindex) from " + tablename + " where " + columnname + " = " + sort;
			OleDbCommand comm = new OleDbCommand(commstr,conn);
			try
			{
				conn.Open();
				int maxcindex = Convert.ToInt32(comm.ExecuteScalar());
				return maxcindex;
			}
			catch
			{
				return 0;
			}
			finally
			{
				conn.Close();
				conn.Dispose();
				comm.Dispose();
			}
		}
		#endregion
		
		#region  编号函数
		public string Getnewid(string tablename,string columnname)
		{
			string newid,month1,day1;

			if (DateTime.Now.Month<10)
				month1 = "0" + DateTime.Now.Month.ToString();
			else
				month1 = DateTime.Now.Month.ToString();

			if (DateTime.Now.Day<10)
				day1 = "0" +DateTime.Now.Day.ToString();
			else
				day1 = DateTime.Now.Day.ToString();

			newid = DateTime.Now.Year.ToString() + month1 +day1;
			
			string sqlstr = "select "+columnname+" from "+tablename+" where left("+columnname+",8)='"+newid+"'";
			OleDbDataReader dr = Reader(sqlstr);
			if(dr.Read())
			{
				string maxstr = "select max("+columnname+") from "+tablename+" where left("+columnname+",8)='"+newid+"'";
				OleDbDataReader maxdr = Reader(maxstr);
				if(maxdr.Read())
				{
					string nowid = maxdr.GetValue(0).ToString().Substring(8,6);
					nowid=Convert.ToString(Convert.ToUInt32(nowid)+1);
					newid=Convert.ToString(newid+nowid);
				}
				maxdr.Close();
				dr.Close();
			}
			else
			{
				newid=newid+"100001";
				dr.Close();
			}
			return newid;
		}
		#endregion

		//MD5编码
		//public string MD5Encoder(string str)
		//{
		//	string result = System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(str,"MD5");
		//	return result;
		//}

		#region 字符串截取函数
		public string CutString(string inputString,int len)
		{


			ASCIIEncoding ascii =  new ASCIIEncoding();
			int tempLen=0;
			string tempString="";
			byte[] s = ascii.GetBytes(inputString);
			for(int i=0;i<s.Length;i++)
			{
				if((int)s[i]==63)
				{
					tempLen+=2;
				}
				else
				{
					tempLen+=1;
				}
                
				try
				{
					tempString+=inputString.Substring(i,1);
				}
				catch
				{
					break;
				}

				if(tempLen>len)
					break;
			}
			//如果截过则加上半个省略号
			byte[] mybyte=System.Text.Encoding.Default.GetBytes(inputString);
			if(mybyte.Length>len)
				tempString+="…";


			return tempString;
		}
		#endregion
	}
}