loadfile.cs

一个WINCE下用ado.net连接数据库的例子 作者:tanis

using System;
using System.Data;
using System.Data.SqlClient;
using System.IO;
using AutoRefresh;
using System.Collections;

namespace AutoRefresh
{
	/// <summary>
	/// 
	/// </summary>
	public class LoadFile
	{

		private string sConnectString = "";//"Persist Security Info=False;User ID=sa;Initial Catalog=pubs;Data Source=60.63.208.231;Packet Size=4096";
		private string sSqlCmdString = "SELECT file_name,file_info,file_size,file_ver,file_exe FROM dbo.TB_FileInfo1";
		private int bufferSize = 50; //Size of the BLOB buffer.
    	private string sOutFileNameString = "";
    	private string sOutFilePathString = "";
		private string sOutFileString = "";
		private string sFileInfo = "";
		private string sFileVer = "";

		private long  lTotalLoadByte = 0;
		private long  lFileSize = 0;
		private long  lrltSize = 0;
		private long  lindex = 0;
		private long  lpointer = 0;

		private Form3 pform = null;
        private string sOutMessage = "";


		public LoadFile(Form3 tpform)
		{
			// 
			// TODO: 在此处添加构造函数逻辑
			sConnectString = "Persist Security Info=False;User ID=sa;Initial Catalog=mysql;Data Source="+ Form1.static_Para.sServerName +";Packet Size=4096";
			sOutFilePathString = Form1.static_Para.sFilePath;
			pform = tpform;
			Form1.static_Para.arrlst.Clear();
			//
		}

		public string GetLastMessage()
		{
			return sOutMessage;
		}

		public bool Start()
		{
			try
			{
				SqlConnection sqlConn = new SqlConnection(sConnectString);
				SqlCommand sqlCmd = new SqlCommand(sSqlCmdString,sqlConn);
				FileStream fs;
				BinaryWriter bw;
				byte[] outbyte = new byte[bufferSize];

				sqlConn.Open();
				SqlDataReader sqlReader = sqlCmd.ExecuteReader(CommandBehavior.SequentialAccess);

				while(sqlReader.Read())
				{
					lindex ++ ;
					lpointer = 0;
					lTotalLoadByte = 0;
					sOutFileString = "";
					lFileSize = 0;
					pform.iPos = 0;
                    //file name
					sOutFileNameString = sqlReader.GetString(0).Trim();
					//file info
					sFileInfo = sqlReader.GetString(1).Trim();
					//file size
					lFileSize = (long)sqlReader.GetInt32(2);
					//flie ver
					sFileVer = sqlReader.GetString(3).Trim();
					//file full path
					sOutFileString = sOutFilePathString + sOutFileNameString;
					//Creat a file
					fs = new FileStream(sOutFileString,FileMode.OpenOrCreate,FileAccess.Write);
					bw = new BinaryWriter(fs);

					//load file

					lrltSize = sqlReader.GetBytes(4, lpointer, outbyte, 0, bufferSize);
					lTotalLoadByte += lrltSize;
                    pform.iPos = (int)(lTotalLoadByte*100 / lFileSize);

					pform.slbOutPut += "开始下载文件：" + sOutFileNameString + " .....\r\n";

					while(lrltSize == bufferSize)
					{
						//未读完
						System.Threading.Thread.Sleep(500);
						bw.Write(outbyte);
						bw.Flush();
						lpointer += lrltSize;
						lrltSize = sqlReader.GetBytes(4, lpointer, outbyte, 0, bufferSize);
						lTotalLoadByte += lrltSize;
						pform.iPos = (int)(lTotalLoadByte*100 / lFileSize);

						if(pform.bAbort == true)
						{
							bw.Write(outbyte);
							bw.Flush();
							bw.Close();
							fs.Close();		
							sqlConn.Close();
							sqlReader.Close();
							return false;
						}
					}

					bw.Write(outbyte);
					bw.Flush();

					bw.Close();
					fs.Close();

					pform.iPos = 100 ;
					Form1.static_Para.arrlst.Add(sOutFileNameString);
					pform.slbOutPut += "文件:" +sOutFileNameString +"下载成功!\r\n";

				}

				sqlConn.Close();
				sqlReader.Close();
				return true;
			}
			catch(Exception ex)
			{
				sOutMessage = ex.Message;
                pform.slbOutPut += sOutMessage + "\r\n";
				return false;
			}
		}
	}
}