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Read excel, search for and replace pieces of text in web C# application

I have an excel file, need access, replace parts of the text and download the changed file.
But I can not save the changes, I should always keep the version on the server.
I did several searches, but I can only change the file and save the changes.
I tried to solve with the link below, I managed to search and change the file, but I do not know how to download and stop saving the changes.
Find and replace text in Excel using C#
Thank you very much

Read the file into a memory stream. Do your changes and write it to a byte array. Use the byte array bytesInstream to download and the original file remains unaltered.
byte[] byteArray = File.ReadAllBytes("excelFile.xlsx");
using (MemoryStream ms = new MemoryStream())
{
ms.Write(byteArray, 0, (int)byteArray.Length);
using (SpreadsheetDocument doc = SpreadsheetDocument.Open(ms, true))
{
// Do work here
}
// Convert it to byte array
byte[] bytesInStream = ms.ToArray();
}
I have assumed you are using openxml to make your changes.

Is it possible to create one dummy file with extension `(.wav)` format?

I am doing Silverlight application. which i need to save data into server.
Is it Possible to Save recorded stream in one dummy file.
Stream stream = saveFileDialog.OpenFile();
WavManager.SavePcmToWav(_sink.BackingStream, stream, _sink.CurrentFormat);
stream.Close();
Instead of selecting user by SaveFileDialog I want to use Dummy file at runtime.
if it possible any one will tell i will greatly appreciate.Advance thanks.

You can use the IsolatedStorageFile to create a temp/dummy file without asking the user to select a file.
The IsolatedStorage is a restricted area for your silverlight application to store files and data.
IsolatedStorageFile store = IsolatedStorageFile.GetUserStoreForApplication ();
IsolatedStorageFileStream stream = store.CreateFile("dummy.wav");
WavManager.SavePcmToWav(_sink.BackingStream, stream, _sink.CurrentFormat);
stream.Close();
Another solution would be to store the data of your .wav file in a in-memory stream. This can be done by using a MemoryStream.

How to save file in SQL Server database if have file path?

I am building some C# desktop application and I need to save file into database. I have come up with some file chooser which give me correct path of the file. Now I have question how to save that file into database by using its path.

It really depends on the type and size of the file. If it's a text file, then you could use File.ReadAllText() to get a string that you can save in your database.
If it's not a text file, then you could use File.ReadAllBytes() to get the file's binary data, and then save that to your database.
Be careful though, databases are not a great way to store heavy files (you'll run into some performance issues).

FileStream fs = new FileStream(fileName, FileMode.Open, FileAccess.Read);
BinaryReader br = new BinaryReader(fs);
int numBytes = new FileInfo(fileName).Length;
byte[] buff = br.ReadBytes(numBytes);
Then you upload it to the DB like anything else, I'm assume you are using a varbinary column (BLOB)

So filestream would be it but since you're using SQL 2K5 you will have to do it the read into memory way; which consumes alot of resources.
First of the column type varchar(max) is your friend this give you ~2Gb of data to play with, which is pretty big for most uses.
Next read the data into a byte array and convert it to a Base64String
FileInfo _fileInfo = new FileInfo(openFileDialog1.FileName);
if (_fileInfo.Length < 2147483647) //2147483647 - is the max size of the data 1.9gb
{
byte[] _fileData = new byte[_fileInfo.Length];
_fileInfo.OpenRead().Read(_fileData, 0, (int)_fileInfo.Length);
string _data = Convert.ToBase64String(_fileData);
}
else
{
MessageBox.Show("File is too large for database.");
}
And reverse the process to recover
byte[] _fileData = Convert.FromBase64String(_data);
You'll want to dispose of those strings as quickly as possible by setting them to string.empty as soon as you have finished using them!
But if you can, just upgrade to 2008 and use FILESTREAM.

If you're using SQL Server 2008, you could use FILESTREAM (getting started guide here). An example of using this functionality from C# is here.

You would need the file into a byte array then store this as a blob field in the database possible with the name you wanted to give the file and the file type.
You could just reverse the process for putting the file out again.

c# - reading/writing blob from firebird

I'm trying to read image from firebird with c#, and save it to file system.
I can read from table and save. but image can not be viewed. I tried many piece of
code on net.but result is same :(
Can any one help me please?

How are you retrieving the code form Firebird? If you are getting the data and casting it to a byte[] try:
byte [] blob = row["image"];
// create a file FileStream to write the data
FileStream fs = new FileStream("image.jpg", FileMode.Create);
fs.Write(blob,0,blob.Length);
fs.Close();
The above code should do the trick.
PS: I have made lots of assumption in the code, but you can get the idea.

Read excel file from a stream

I need a way to read a Excel file from a stream. It doesn't seem to work with the ADO.NET way of doing things.
The scenario is that a user uploads a file through a FileUpload and i need to read some values from the file and import to a database.
For several reasons I can't save the file to disk, and there is no reason to do so either.
So, anyone know of a way to read a Excel file from a FileUpload stream?

It seems i found a soultion to the problem myself.
http://www.codeplex.com/ExcelDataReader
This library seems to work nicely and it takes a stream to read the excel file.
ExcelDataReader reader = new ExcelDataReader(ExcelFileUpload.PostedFile.InputStream);

This can be done easily with EPPlus.
//the excel sheet as byte array (as example from a FileUpload Control)
byte[] bin = FileUpload1.FileBytes;
//gen the byte array into the memorystream
using (MemoryStream ms = new MemoryStream(bin))
using (ExcelPackage package = new ExcelPackage(ms))
{
//get the first sheet from the excel file
ExcelWorksheet sheet = package.Workbook.Worksheets[1];
//loop all rows in the sheet
for (int i = sheet.Dimension.Start.Row; i <= sheet.Dimension.End.Row; i++)
{
//loop all columns in a row
for (int j = sheet.Dimension.Start.Column; j <= sheet.Dimension.End.Column; j++)
{
//do something with the current cell value
string currentCellValue = sheet.Cells[i, j].Value.ToString();
}
}
}

SpreadsheetGear can do it:
SpreadsheetGear.IWorkbook workbook = SpreadsheetGear.Factory.GetWorkbookSet().Workbooks.OpenFromStream(stream);
You can try it for yourself with the free evaluation.
Disclaimer: I own SpreadsheetGear LLC

Infragistics has an excel component that can read an excel file from a stream.
I'm using it in a project here and it works well.
Also the open source myXls component could easily be modified to support this. The XlsDocument contstructor only supports loading from a file given by a file name, but it works by creating a FileStream and then reading the Stream, so changing it to support loading from streams should be trivial.
Edit:
I see that you found a solution but I just wanted to note that I updated the source code for the component so that it now can read an excel file directly from a stream. :-)

I use ClosedXML nuget package to read excel content from stream. It has a constructor overload in XLWorkbook class which takes stream pointing to an excel file (aka workbook).
imported namespace at the top of your code file:
using ClosedXML.Excel;
Source code:
var stream = /*obtain the stream from your source*/;
if (stream.Length != 0)
{
//handle the stream here
using (XLWorkbook excelWorkbook = new XLWorkbook(stream))
{
var name = excelWorkbook.Worksheet(1).Name;
//do more things whatever you like as you now have a handle to the entire workbook.
var firstRow = excelWorkbook.Worksheet(1).Row(1);
}
}