I have code that I copied from the tutorial that I watch and our code is so similar in the tutorial.
When the presenter runs the code, it runs ok, but when I try to run my code which is the same as in the tutorial, I get an error "the parameter is not valid".
Please help
private void Viewbutton_Click(object sender, EventArgs e)
{
conection.Open();
string sqlQuery = "select studnum, course, f_name, l_name, color_image from table3 where studnum='" + textBox1.Text + "'";
cmd = new SqlCommand(sqlQuery, conection);
SqlDataReader dataread = cmd.ExecuteReader();
dataread.Read();
if (dataread.HasRows)
{
lblstudnum.Text = dataread[0].ToString();
lblcourse.Text = dataread[1].ToString();
lblfname.Text = dataread[2].ToString();
lbllname.Text = dataread[3].ToString();
byte[] images = (byte[])dataread[4];
if(images==null)
{
pictureBox1.Image = null;
}
else
{
MemoryStream mstreem = new MemoryStream(images);
pictureBox1.Image = Image.FromStream(mstreem);
}
}
else
{
MessageBox.Show("this data not available");
}
}
The error line is the
pictureBox1.Image = Image.FromStream(mstreem);
Better to use parametric query and column name instead of using [0],[1] etc.. The Memory Stream is used by Data reader.So you shall use as below, provided a valid Image is saved in database
var con = new SqlConnection("the connection string to database");
con.Open();
SqlCommand cmd = new SqlCommand(#"sql query",con);
byte[] images = null;
using (SqlDataReader dataread = cmd.ExecuteReader())
{
if (dataread.Read())
{
//lblstudnum.Text = dataread[0].ToString();
//lblcourse.Text = dataread[1].ToString();
//lblfname.Text = dataread[2].ToString();
//lbllname.Text = dataread[3].ToString();
images = (byte[])dataread["color_image"];// column name is recommended
}
}
con.Close();
if (images == null)
{
pictureBox1.Image = null;
}
else
{
MemoryStream mstreem = new MemoryStream(images);
pictureBox1.Image = Image.FromStream(mstreem);
}
Probably not a valid image. Add some debugging code to your program (or set up a watch) that will output the length of the memory stream and its first few bytes. Make sure the length is what you were expecting. Make sure the file prefix is there, if any, e.g. bitmap files have a two-letter alphanumeric prefix. Make sure it didn't get truncated. Make sure it is an allowed file format. The problem may be that your instructor's database has data in it while yours doesn't.
Related
Good day, I have this error when I'm trying to insert my encrypted data to my Database
Now here's my script for Encryption
public void Encrypt(TextBox txtEncrypt, string hash, byte[] results)
{
hash = "placeholder";
byte[] data = UTF8Encoding.UTF8.GetBytes(txtEncrypt.Text);
using (MD5CryptoServiceProvider md5 = new MD5CryptoServiceProvider())
{
byte[] keys = md5.ComputeHash(UTF8Encoding.UTF8.GetBytes(hash));
using (TripleDESCryptoServiceProvider tripDes = new TripleDESCryptoServiceProvider() { Key = keys, Mode = CipherMode.ECB, Padding = PaddingMode.PKCS7 })
{
ICryptoTransform transform = tripDes.CreateEncryptor();
results = transform.TransformFinalBlock(data, 0, data.Length);
txtEncrypt.Text = Convert.ToBase64String(results, 0, results.Length);
//MessageBox.Show("Encryption :" + Convert.ToBase64String(results,0,results.Length));
}
}
}
Now I am implementing it on another class like this
private void btnRegister_Click(object sender, EventArgs e)
{
try
{
//Best practice in c# to interact with database (using statement)
using (MySqlConnection mysqlCon = new MySqlConnection(connection.connectionString))
{
mysqlCon.Open();
//Add the stored procedure that we uses in the mysqlworkbench
MySqlCommand mysqlCmd = new MySqlCommand("LoginAdd", mysqlCon);
mysqlCmd.CommandType = CommandType.StoredProcedure;
//Use trim to avoid spaces
method.Encrypt(textBox2,hash,results);
mysqlCmd.Parameters.AddWithValue("_LoginID", LoginID);
mysqlCmd.Parameters.AddWithValue("_LoginUser", textBox1.Text.Trim());
mysqlCmd.Parameters.AddWithValue("_LoginPass", textBox2);
mysqlCmd.ExecuteNonQuery();
MessageBox.Show("Registered Succesfully");
//proceed to login page
this.Hide();
method.ConstantLoginForm();
}
}
catch(Exception ex)
{
MessageBox.Show(""+ ex);
}
}
I already search some data's and I found this.
I tried doing it but nothing happens
Set your _LoginPass column size to varchar(50) or more.
As Charles May said I've left of the .Text part and are trying to pass in the object.
So I just need to change this part
mysqlCmd.Parameters.AddWithValue("_LoginPass", textBox2);
to this some like this code
mysqlCmd.Parameters.AddWithValue("_LoginPass", textBox2.Text.Trim());
I know how to get a picture from a databse as Byte array :
string query2 = "SELECT Logo FROM Client WHERE CompanyName = '"+CN+"' ;";
using (SqlCeCommand command1 = new SqlCeCommand(query2, connection))
{
try
{
SqlCeDataReader reader3 = command1.ExecuteReader();
while (reader3.Read())
{
byte[] byteArray = (byte[])reader3["Logo"];
Image img = byteArrayToImage(byteArray);
}
}
catch (Exception excf)
{
MessageBox.Show(excf.Message);
}
}
I know how to replace some text by an image using the image's path :
var kword = "#Logo#";
var sel = app.Selection;
sel.Find.Text = kword;
sel.Find.Execute(Replace: WdReplace.wdReplaceOne);
sel.Range.Select();
sel.InlineShapes.AddPicture(imagePath);
But I don't know (and I realy can't figure out how to replace some text by the image I got in my database.
I'm sure there is something obvious that I'm missing but I didn't find the answer on google.
Thank you
https://social.msdn.microsoft.com/Forums/office/en-US/c2a89c07-f8e4-4b3b-9db9-251dc042564b/adding-a-image-from-a-byte-array-into-an-ooxml-word-document?forum=oxmlsdk
Please visit the above link.. It might be of some help on the above Issue.
I am trying to upload a file from disk and then insert the file into a varbinary db column.
I can't seem to figure out how to insert the binary file.
I am using C# and Linq to Sql in a WPF application.
Here is what I am trying so far! Any suggestions or advice would be appreciated.
private void UploadFile()
{
DatabaseData.DataClassesDataContext context = new DatabaseData.DataClassesDataContext();
{
OpenFileDialog dlgOpen = new OpenFileDialog();
dlgOpen.Title = "Select file";
FileData fd = new FileData();
if (dlgOpen.ShowDialog() ?? false)
{
FileStream inStream = File.OpenRead(dlgOpen.FileName);
//FileStream outStream = File.OpenWrite(dlgOpen.FileName + ".xlsx");
int b;
while ((b = inStream.ReadByte()) > -1)
// outStream.WriteByte((byte)b);
fd.FileId = Guid.NewGuid();
//fd.DataFile = inStream;//DataFile is the Varbinary column in the db
fd.Title = dlgOpen.FileName;
fd.FileExtension = txtExtension.text;
context.FileDatas.InsertOnSubmit(fd);
context.SubmitChanges();
//outStream.Flush();
//outStream.Close();
inStream.Close();
}
}
}
Not sure if this will work, but try this
if (dlgOpen.ShowDialog() ?? false)
{
byte[] bytes = System.IO.File.ReadAllBytes(dlgOpen.FileName);
fd.FileId = Guid.NewGuid();
fd.DataFile = bytes;
fd.Title = dlgOpen.FileName;
context.FileDatas.InsertOnSubmit(fd);
context.SubmitChanges();
To fix the compile error, remove the while statement. You're trying to create a new FileData() which can never be used until b > -1.
I don't know that the code will work after that, but it will fix this one compile error.
private void UploadFile()
{
DatabaseData.DataClassesDataContext context = new DatabaseData.DataClassesDataContext();
{
OpenFileDialog dlgOpen = new OpenFileDialog();
dlgOpen.Title = "Select file";
if (dlgOpen.ShowDialog() ?? false)
{
FileStream inStream = File.OpenRead(dlgOpen.FileName);
FileData fd = new FileData();
fd.FileId = Guid.NewGuid();
fd.DataFile = inStream;
fd.Title = dlgOpen.FileName;
fd.FileExtension = txtExtension.text;
context.FileDatas.InsertOnSubmit(fd);
context.SubmitChanges();
inStream.Close();
}
}
}
Well, you read my disclaimer in your comments. I can't guarantee any pros here would agree with the approach it's per your request. I am just learning C# the right way and got the idea to convert a working non-database program. I needed this to convert all my existing data into a new database that was to take over storage:
/* Spawned from a button click
...
*/
//
// Here I bring in the directory which you'll likely replace with
// a single file
//
string[] files =
Directory.GetFiles(
#"yourDicectory");
//
// At this point you may disregard my loop if needed
//
foreach (string file in files)
{
//
// Here the entire files are read and split
// Handle your data how you like
//
StreamReader fileReader = new StreamReader( file );
string lines = fileReader.ReadToEnd();
string[] entries = lines.Split( ',' );
//
// Here, omitted, I declare variables of types to insert "holders"
// Every CSV has to go to a corresponding holder of the
// the appropriate type (i.e., DateTime, decimal(money), or yourType)
//
SqlCeConnection con = new SqlCeConnection( "Data Source = YourDataSource.sdf" );
con.Open();
SqlCeCommand cmd = con.CreateCommand();
//
// The insert command that takes the parsed values - value1, value2, ...
// which are the named and omitted declarations from above
// You're providing a signature of the table you're inserting into
//
cmd.CommandText = "INSERT INTO YourTable ([Column1], [Column2], [Column3], ... , [Column(n)]) VALUES (value1, value2, value3, ... , value(n))";
//
// Here, omitted, I parse and convert the values and store them in the holders
//
// Now execute and catch if needed
try
{
cmd.ExecuteNonQuery();
}
catch( SqlCeException sqle )
{
myTextbox.Text += sqle.Errors.ToString() + "\n";
}
}
//
// Update my view - May not apply
//
myGridView1.Update();
con.Close();
}
/* Do whatever else you'd like ... */
File operations in C# (my blog link will help you)
what I've been trying to find out is how I can store the BLOB of an image into my database without saving it to the filesystem first, so directly from the server's memory.
I use an sql server and among other form information I have 2 images that need to be stored in the database. I would also like to know how I can read them out and convert them back to images.
In the db I have "Thumbnail" which is of type "image". That should be correct if I'm not wrong.
For the image upload I use the following asp control:
<asp:FileUpload ID="_imageUpload" runat="server" />
I have never done anything like this as I am quite new to working with databases especially together with websites.
Oh, and sorry if this question has been asked and answered already.
Thanks in advance!
[edit]
My entire code:
protected void _uploadImageBtn_Click(object sender, EventArgs e)
{
string extension;
// checks if file exists
if (!_imageUpload.HasFile)
{
_resultLbl.Text = "Please, Select a File!";
return;
}
// checks file extension
extension = System.IO.Path.GetExtension(_imageUpload.FileName).ToLower();
if (!extension.Equals(".jpg") && !extension.Equals(".jpeg") && !extension.Equals(".png"))
{
_resultLbl.Text = "Only image files (.JPGs and .PNGs) are allowed.";
return;
}
// checks if image dimensions are valid
if (!ValidateFileDimensions(140, 152))
{
_resultLbl.Text = "Maximum allowed dimensions are: width 1520px and height <= 140px.";
return;
}
int fileLen;
string displayString = "";
// Get the length of the file.
fileLen = _imageUpload.PostedFile.ContentLength;
// Create a byte array to hold the contents of the file.
byte[] input = new byte[fileLen - 1];
input = _imageUpload.FileBytes;
// Copy the byte array to a string.
for (int loop1 = 0; loop1 < fileLen; loop1++)
{
displayString = displayString + input[loop1].ToString();
}
try
{
SqlConnection sqlCn = new SqlConnection("Data Source=localhost;Initial Catalog=database;User ID=user;Password=pw");
string qry = "INSERT INTO Project (thumbnail) VALUES (#thumbnail)";
SqlCommand sqlCom = new SqlCommand(qry, sqlCn);
sqlCom.Parameters.Add("#thumbnail", SqlDbType.Image, input.Length).Value = input;
sqlCn.Open();
sqlCom.ExecuteNonQuery();
sqlCn.Close();
}
catch (Exception)
{
(...)
}
}
public bool ValidateFileDimensions(int aHeight, int aWidth)
{
using (System.Drawing.Image image = System.Drawing.Image.FromStream(_imageUpload.PostedFile.InputStream))
{
return (image.Height == aHeight && image.Width == aWidth);
}
}
You can save the returned byte array from FileUpload.FileBytes.
if(_imageUpload.HasFile)
{
byte[] imageData = _imageUpload.FileBytes;
using(SqlConnection sqlCn = new SqlConnection("Server=localhost;database=databaseName;uid=userName;pwd=password"))
{
string qry = "INSERT INTO Project (thumbnail) VALUES (#thumbnail)";
using(SqlCommand sqlCom = new SqlCommand(qry, sqlCn))
{
sqlCom.Parameters.Add("#thumbnail",
SqlDbType.Image,
imageData.Length).Value=imageData;
sqlCn.Open();
sqlCom.ExecuteNonQuery();
sqlCn.Close();
}
}
}
EDIT:
protected void _uploadImageBtn_Click(object sender, EventArgs e)
{
string extension;
// checks if file exists
if (!_imageUpload.HasFile)
{
_resultLbl.Text = "Please, Select a File!";
return;
}
// checks file extension
extension = System.IO.Path.GetExtension(_imageUpload.FileName).ToLower();
if (!extension.Equals(".jpg") && !extension.Equals(".jpeg") && !extension.Equals(".png"))
{
_resultLbl.Text = "Only image files (.JPGs and .PNGs) are allowed.";
return;
}
// checks if image dimensions are valid
if (!ValidateFileDimensions(140, 152))
{
_resultLbl.Text = "Maximum allowed dimensions are: width 1520px and height <= 140px.";
return;
}
byte []input = _imageUpload.FileBytes;
SqlConnection sqlCn = new SqlConnection("Data Source=localhost;Initial
Catalog=database;User ID=user;Password=pw");
string qry = "INSERT INTO Project (thumbnail) VALUES (#thumbnail)";
SqlCommand sqlCom = new SqlCommand(qry, sqlCn);
sqlCom.Parameters.Add("#thumbnail", SqlDbType.Image, input.Length).Value = input;
sqlCn.Open();
sqlCom.ExecuteNonQuery();
sqlCn.Close();
}
I've gone editing code -> which is never a good thing!
the code is for a file uploader in MVC. The thing was I was uploading two files at a time which meant they were inserted into separate rows in a database. This is the original code:
public ActionResult Index()
{
ViewData["Message"] = "Convert your eBooks!";
foreach (string upload in Request.Files)
{
if (!Request.Files[upload].HasFile1()) continue;
string mimeType = Request.Files[upload].ContentType;
Stream fileStream = Request.Files[upload].InputStream;
string fileName = Path.GetFileName(Request.Files[upload].FileName);
int fileLength = Request.Files[upload].ContentLength;
byte[] fileData = new byte[fileLength];
fileStream.Read(fileData, 0, fileLength);
const string connect = #"Server=localhost;Database=Images;user id=taraw; password=siemensbs;";
using (var conn = new SqlConnection(connect))
{
var qry = "INSERT INTO FileStore (FileContent, MimeType, FileName) VALUES (#FileContent, #MimeType, #FileName)";
var cmd = new SqlCommand(qry, conn);
cmd.Parameters.AddWithValue("#FileContent", fileData);
cmd.Parameters.AddWithValue("#MimeType", mimeType);
cmd.Parameters.AddWithValue("#FileName", fileName);
conn.Open();
cmd.ExecuteNonQuery();
}
}
return View();
}
Here is my attempt at modifying the code in order to take in the files separately as opposed to using a loop, and inserting them into a single row in a database table:
public ActionResult Index()
{
if (!Request.Files["FileUpload1"].HasFile1())
{
string mimeTypePDF = Request.Files["FileUpload1"].ContentType;
Stream fileStreamPDF = Request.Files["FileUpload1"].InputStream;
string fileNamePDF = Path.GetFileName(Request.Files["FileUpload1"].FileName);
int fileLengthPDF = Request.Files["FileUpload1"].ContentLength;
byte[] fileDataPDF = new byte[fileLengthPDF];
fileStreamPDF.Read(fileDataPDF, 0, fileLengthPDF);
}
if(!Request.Files["FileUpload2"].HasFile1())
{
string mimeTypeCover = Request.Files["FileUpload2"].ContentType;
Stream fileStreamCover = Request.Files["FileUpload2"].InputStream;
string fileNameCover = Path.GetFileName(Request.Files["FileUpload2"].FileName);
int fileLengthCover = Request.Files["FileUpload2"].ContentLength;
byte[] fileDataCover = new byte[fileLengthCover];
fileStreamCover.Read(fileDataCover, 0, fileLengthCover);
}
const string connect = #"Server=localhost;Database=Images;user id=taraw; password=siemensbs;";
using (var conn = new SqlConnection(connect))
{
var qry = "INSERT INTO Book (FileContentPDF, MimeTypePDF, FileNamePDF, FileContentCover, MimeTypeCover, FileNameCover) VALUES (#FileContentPDF, #MimeTypePDF, #FileNamePDF, #FileContentCover, #MimeTypeCover, #FileNameCover)";
var cmd = new SqlCommand(qry, conn);
cmd.Parameters.AddWithValue("#FileContentPDF", fileDataPDF);
cmd.Parameters.AddWithValue("#MimeTypePDF", mimeTypePDF);
cmd.Parameters.AddWithValue("#FileNamePDF", fileNamePDF);
cmd.Parameters.AddWithValue("#FileContentCover", fileDataCover);
cmd.Parameters.AddWithValue("#MimeTypeCover", mimeTypeCover);
cmd.Parameters.AddWithValue("#FileNameCover", fileNameCover);
conn.Open();
cmd.ExecuteNonQuery();
}
return View();
}
Now I get the following errors for each cmd.Parameters.AddWithValue:
The name 'fileDataPDF' does not exist
in the current context
I'm presuming this is because it is outside of the IF statements but I'm a bit stuck on how to structure it. I eventually want to use linq to insert the files into the database as the above method is not ideal, but my main aim for now is to just get this bit working.
Any help would be appreciated greatly :)
You need to declare the variables outside of the if conditional scopes. e.g.
string mimeTypePDF;
string fileNamePDF;
byte[] fileDataPDF;
if (!Request.Files["FileUpload1"].HasFile1())
{
mimeTypePDF = Request.Files["FileUpload1"].ContentType;
Stream fileStreamPDF = Request.Files["FileUpload1"].InputStream;
fileNamePDF = Path.GetFileName(Request.Files["FileUpload1"].FileName);
int fileLengthPDF = Request.Files["FileUpload1"].ContentLength;
fileDataPDF = new byte[fileLengthPDF];
fileStreamPDF.Read(fileDataPDF, 0, fileLengthPDF);
}
(Fwiw, I think there are better ways to handle this multifile upload, but the above is simplest way to handle your question.)
You need to declare fileDataPDF outside the if statement, otherwise its only visible to the if block.
How about byte[] fileDataPDF; before if
and fileDataPDF = new byte[fileLengthPDF]; inside if?