文件保存到数据库内存泄露求教

qwww450728 2012-02-28 11:31:05

没上传一个文件总会有约100M内存没有被释放掉求原因
//上传
private void btnSubmit_Click(object sender, EventArgs e)
{
//txbFileFullPath.Text 文件全路径
using (FileStream fs = new FileStream(txbFileFullPath.Text, FileMode.Open))
{
byte[] bytes;
try
{
bytes = new byte[fs.Length];
fs.Read(bytes, 0, bytes.Length);
}
catch (Exception ex)
{
MessageBox.Show("错误信息：" + ex.Message, "文件读取出错", MessageBoxButtons.OK, MessageBoxIcon.Error);
return;
}
string strSQL = "Insert into FileData ( [FileName], Filter, FileBytes, UpLoadTime ) values ( @FileName, @Filter, @FileBytes, @UpLoadTime);";
SqlParameter[] cmdParms = new SqlParameter[]
{
new SqlParameter("@FileName",SqlDbType.VarChar),
new SqlParameter("@Filter", SqlDbType.VarChar),
new SqlParameter("@FileBytes", SqlDbType.VarBinary),
new SqlParameter("@UpLoadTime",SqlDbType.DateTime)
};
cmdParms[0].Value = txbFileName.Text;
cmdParms[1].Value = lbFileType.Text;
cmdParms[2].Value = bytes;
cmdParms[3].Value = DateTime.Now;
DB db = new DB();
db.ExecuteNonQuery( CommandType.Text, strSQL, cmdParms);
fs.Dispose();
btnSubmit.Enabled = false;
}
}

/// <summary>
/// 生成文件
/// </summary>
/// <param name="pReadByte">二进制流</param>
/// <param name="fileName">文件全路径</param>
private void WriteFile(byte[] pReadByte, string fileName)
{
FileStream fs = new FileStream(fileName, FileMode.OpenOrCreate);
try
{
fs.Write(pReadByte, 0, pReadByte.Length);

}
catch (Exception ex)
{
MessageBox.Show("错误信息：" + ex.Message, "文件生成出错", MessageBoxButtons.OK, MessageBoxIcon.Error);
return;
}
finally
{
if (fs != null)
fs.Close();
}

}

//下载
private void btnDownLoad_Click(object sender, EventArgs e)
{

string strFileName = string.Empty;

string sql = " Select [FileName], Filter, FileBytes from FileData where ID = " + txbFileID.Text.Trim();

DB db = new DB();
//数据表
using (SqlDataReader sdr = db.GetReader(sql))
{

while (sdr.Read())
{
strFileName = sdr.GetString(0);
byte[] bytes = (byte[])sdr[2];
//保存窗体
using (SaveFileDialog saveDialog = new SaveFileDialog())
{
saveDialog.CheckPathExists = true;
saveDialog.DefaultExt = sdr.GetString(1);
saveDialog.FileName = strFileName;
saveDialog.Filter = "*." + sdr.GetString(1) +"|*.*"; //"文本文件(*.txt)|*.txt|所有文件(*.*)|*.*"
if (saveDialog.ShowDialog() == DialogResult.OK)
{
strFileName = saveDialog.FileName;
WriteFile(bytes, strFileName);
}
}
}
}
}
//=====================数据库操作类=============================
public class DB
{
private string _ConStr = string.Empty;
private SqlConnection _Conn;
public DB()
{
string _server = ConfigurationManager.AppSettings["Server"];
string _uid = ConfigurationManager.AppSettings["User"];
string _pwd = ConfigurationManager.AppSettings["Password"];
string _database = ConfigurationManager.AppSettings["Database"];
_ConStr = "server=" + _server + ";uid=" + _uid + ";pwd=" + _pwd + ";database=" + _database;
GetConn();
}

/// <summary>
/// 实例化数据库连接
/// </summary>
public void GetConn()
{
_Conn = new SqlConnection(_ConStr);

}
/// <summary>
/// 对数据库查询
/// </summary>
/// <param name="Sql"> SQL查询语句 string类型</param>
/// <returns>返回一张表 DataTable</returns>
public DataTable GetTable(string Sql)
{
_Conn.Open();
SqlDataAdapter DA = new SqlDataAdapter(Sql, _Conn);
DataSet DS = new DataSet();
DA.Fill(DS);
_Conn.Close();
DataTable DTable = DS.Tables[0];
return DTable;
}

public SqlDataReader GetReader(string Sql)
{
try
{
_Conn.Open();
SqlCommand Cmd = new SqlCommand(Sql, _Conn);
SqlDataReader Reader = Cmd.ExecuteReader();
return Reader;
}
finally
{
//_Conn.Close();
}
}

/// <summary>
/// 用现有的数据库连接执行一个sql命令（不返回数据集）
/// </summary>
/// <param name="conn">一个现有的数据库连接</param>
/// <param name="commandType">命令类型(存储过程, 文本, 等等)</param>
/// <param name="commandText">存储过程名称或者sql命令语句</param>
/// <param name="commandParameters">执行命令所用参数的集合</param>
/// <returns>执行命令所影响的行数</returns>
public int ExecuteNonQuery(CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
{
using (SqlCommand cmd = new SqlCommand())
{
PrepareCommand(cmd, _Conn, null, cmdType, cmdText, commandParameters);
int val = cmd.ExecuteNonQuery();
cmd.Parameters.Clear();
_Conn.Close();
_Conn.Dispose();
return val;
}
}

/// <summary>
/// 准备执行一个命令
/// </summary>
/// <param name="cmd">sql命令</param>
/// <param name="conn">Sql连接</param>
/// <param name="trans">Sql事务</param>
/// <param name="cmdType">命令类型例如存储过程或者文本</param>
/// <param name="cmdText">命令文本,例如：Select * from Products</param>
/// <param name="cmdParms">执行命令的参数</param>
private void PrepareCommand(SqlCommand cmd, SqlConnection conn, SqlTransaction trans, CommandType cmdType, string cmdText, SqlParameter[] cmdParms)
{

if (conn.State != ConnectionState.Open)
conn.Open();

cmd.Connection = conn;
cmd.CommandText = cmdText;

if (trans != null)
cmd.Transaction = trans;

cmd.CommandType = cmdType;

if (cmdParms != null)
{
foreach (SqlParameter parm in cmdParms)
cmd.Parameters.Add(parm);
}
}
}

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