G
Guest
Hi,
I am trying to save and read an image from MS Access DB based on the
following article:
http://www.vbdotnetheaven.com/Code/Sept2003/2175.asp
Right now, I saved images without any errors. After reading the ole object
from db, I saved it to C: as file1.bmp and displayed on the web. But it can
not be displayed. After I manually sent the file to wordpad, it shows
System.Byte [ ]
Now I suspect my saving an image might be wrong. The table has 2 columns:
username and userfile. Userfile column shows
..ong binary data
I can not find a way to verify if data was saved ok? But saving does not
report any errors. I am attached my saving and reading codes here to see if
anyone can help?
THanks. –dale
private void btnSaveToDB_Click(object sender, System.EventArgs e)
{
if (dListUsers.SelectedValue == "")
{
lblFileAccess.Text = "You need to select an user first!";
return;
}
curFileName = myFile.PostedFile.FileName;
// only the attched file name not its path
string c = System.IO.Path.GetFileName(curFileName);
// Read a bitmap contents in a stream
FileStream fs = new FileStream(curFileName, FileMode.OpenOrCreate,
FileAccess.Read);
byte[] rawData = new byte[fs.Length];
fs.Read(rawData, 0, System.Convert.ToInt32(fs.Length));
fs.Close();
// Construct a SQL string and a connection object
OleDbConnection dbConn;
OleDbCommand dbCmd;
string applicationState = ((string)(Application["DBType"])).ToLower();
string sConn = dbClass.Connect(applicationState);
string sSQL;
sSQL = ("INSERT INTO UserFiles (UserName,UserFile) "
+ ("VALUES ("
+ (dbClass.DelimString(dListUsers.SelectedValue) + (","
+ ("\'"+rawData + "\')")))));
try
{
// write the visit log entry
dbConn = new OleDbConnection(sConn);
dbConn.Open();
dbCmd = new OleDbCommand(sSQL, dbConn);
dbCmd.ExecuteNonQuery();
dbConn.Close();
lblFileAccess.Text = "The file has been saved successfully for "
+ dListUsers.SelectedValue + ".";
return;
}
catch (Exception excep)
{
Debug.WriteLine(excep.Message);
lblFileAccess.Text = "The file has not been saved successfully for "
+ dListUsers.SelectedValue + ".";
return;
}
}
private void btnReadFmDB_Click(object sender, System.EventArgs e)
{
OleDbConnection dbConn;
OleDbCommand dbCmd;
OleDbDataReader dbDR;
string applicationState = ((string)(Application["DBType"])).ToLower();
string sConn = dbClass.Connect(applicationState);
// Construct a SQL string and a connection object
string sql = "SELECT UserFile FROM UserFiles WHERE Username =\'"
+ dListUsers.SelectedValue + "\'";
FileStream fs;
BinaryWriter bw;
int bufferSize = 300000;
//byte[] outbyte;
byte[] outbyte = new byte[300000 - 1];
long retval;
//long startIndex = 0;
//string pub_id = "";
try
{
dbConn = new OleDbConnection(sConn);
dbConn.Open();
dbCmd = new OleDbCommand(sql, dbConn);
dbDR = dbCmd.ExecuteReader(CommandBehavior.CloseConnection);
while (dbDR.Read())
{
fs = new FileStream(savedImageName, FileMode.OpenOrCreate,
FileAccess.Write);
bw = new BinaryWriter(fs);
//startIndex = 0;
retval = dbDR.GetBytes(0, 0, outbyte, 0, bufferSize);
bw.Write(outbyte);
bw.Flush();
// Close the output file.
bw.Close();
fs.Close();
}
// get the end
dbConn.Close();
}
catch (Exception excep)
{
Debug.WriteLine(excep.Message);
return;
}
// Display image
//curImage = System.Web.UI.WebControls.Image.FromFile(savedImageName);
imgBox.ImageUrl = savedImageName;
}
I am trying to save and read an image from MS Access DB based on the
following article:
http://www.vbdotnetheaven.com/Code/Sept2003/2175.asp
Right now, I saved images without any errors. After reading the ole object
from db, I saved it to C: as file1.bmp and displayed on the web. But it can
not be displayed. After I manually sent the file to wordpad, it shows
System.Byte [ ]
Now I suspect my saving an image might be wrong. The table has 2 columns:
username and userfile. Userfile column shows
..ong binary data
I can not find a way to verify if data was saved ok? But saving does not
report any errors. I am attached my saving and reading codes here to see if
anyone can help?
THanks. –dale
private void btnSaveToDB_Click(object sender, System.EventArgs e)
{
if (dListUsers.SelectedValue == "")
{
lblFileAccess.Text = "You need to select an user first!";
return;
}
curFileName = myFile.PostedFile.FileName;
// only the attched file name not its path
string c = System.IO.Path.GetFileName(curFileName);
// Read a bitmap contents in a stream
FileStream fs = new FileStream(curFileName, FileMode.OpenOrCreate,
FileAccess.Read);
byte[] rawData = new byte[fs.Length];
fs.Read(rawData, 0, System.Convert.ToInt32(fs.Length));
fs.Close();
// Construct a SQL string and a connection object
OleDbConnection dbConn;
OleDbCommand dbCmd;
string applicationState = ((string)(Application["DBType"])).ToLower();
string sConn = dbClass.Connect(applicationState);
string sSQL;
sSQL = ("INSERT INTO UserFiles (UserName,UserFile) "
+ ("VALUES ("
+ (dbClass.DelimString(dListUsers.SelectedValue) + (","
+ ("\'"+rawData + "\')")))));
try
{
// write the visit log entry
dbConn = new OleDbConnection(sConn);
dbConn.Open();
dbCmd = new OleDbCommand(sSQL, dbConn);
dbCmd.ExecuteNonQuery();
dbConn.Close();
lblFileAccess.Text = "The file has been saved successfully for "
+ dListUsers.SelectedValue + ".";
return;
}
catch (Exception excep)
{
Debug.WriteLine(excep.Message);
lblFileAccess.Text = "The file has not been saved successfully for "
+ dListUsers.SelectedValue + ".";
return;
}
}
private void btnReadFmDB_Click(object sender, System.EventArgs e)
{
OleDbConnection dbConn;
OleDbCommand dbCmd;
OleDbDataReader dbDR;
string applicationState = ((string)(Application["DBType"])).ToLower();
string sConn = dbClass.Connect(applicationState);
// Construct a SQL string and a connection object
string sql = "SELECT UserFile FROM UserFiles WHERE Username =\'"
+ dListUsers.SelectedValue + "\'";
FileStream fs;
BinaryWriter bw;
int bufferSize = 300000;
//byte[] outbyte;
byte[] outbyte = new byte[300000 - 1];
long retval;
//long startIndex = 0;
//string pub_id = "";
try
{
dbConn = new OleDbConnection(sConn);
dbConn.Open();
dbCmd = new OleDbCommand(sql, dbConn);
dbDR = dbCmd.ExecuteReader(CommandBehavior.CloseConnection);
while (dbDR.Read())
{
fs = new FileStream(savedImageName, FileMode.OpenOrCreate,
FileAccess.Write);
bw = new BinaryWriter(fs);
//startIndex = 0;
retval = dbDR.GetBytes(0, 0, outbyte, 0, bufferSize);
bw.Write(outbyte);
bw.Flush();
// Close the output file.
bw.Close();
fs.Close();
}
// get the end
dbConn.Close();
}
catch (Exception excep)
{
Debug.WriteLine(excep.Message);
return;
}
// Display image
//curImage = System.Web.UI.WebControls.Image.FromFile(savedImageName);
imgBox.ImageUrl = savedImageName;
}