How to copy / replace a file to a folder on VB.NET?

Question

I used File.Copy(source, target, True) , where source is the full path name, for example c:\source.txt and target is a folder that can contain the same file. I want to copy source.txt to the destination folder and overwrite if the file already exists.

But I got the error:

'Target is a folder, not a file

Answer 1

The target should also contain the file name:

 sSource = "C:\something.txt" sTarget = "C:\folder\something.txt" File.Copy(sSource, sTarget, True) 

If you want the program name to have the same file name:

 File.Copy(sSource, Path.Combine(sFolder, Path.GetFileName(sSource)), True) 

Read the MSDN Documentation for examples and information on exceptions and method use.

Answer 2

You can also use FileStream to read and write the contents of a file. If you use a file stream, you can read and write all types of binary files, not just text files.

Use the following procedure:

 ''' <summary> ''' copies a file from one location to another ''' </summary> ''' <param name="inputPath">full path to the input file</param> ''' <param name="outputPath">full path to the output file</param> ''' <param name="bufferSize">the size in bytes as an integer that will be read and written at a time from input file and to the output file</param> ''' <param name="overwrite">overwrite the output file if it already exists</param> ''' <returns></returns> Public Function CopyFile(ByVal inputPath As String, ByVal outputPath As String, ByVal bufferSize As Integer, Optional ByVal overwrite As Boolean = False) As Boolean Dim PathIsClear As Boolean = True, SucOpt As Boolean = False Dim inputByteReaderObj As System.IO.FileStream = System.IO.File.Open(inputPath, IO.FileMode.Open) 'open a file stream for reading bytes from the input file Dim endofSize As Integer = My.Computer.FileSystem.GetFileInfo(inputPath).Length If overwrite AndAlso FileExists(outputPath) Then 'if file exits, delete the output file PathIsClear = False PathIsClear = DeleteFilesOnDisk(outputPath) ' Delete the output file if it already exists End If ' Adjust array length for VB array declaration. Dim allBytesRead As Integer = 0, sucessfullBytes As Integer = 0, bytes As Byte() 'The byte array If bufferSize > endofSize Then bufferSize = endofSize End If If bufferSize >= 1 Then bytes = New Byte(bufferSize - 1) {} 'The byte array; create a byte array that will hold the data in length equal to the bufferSize; the array index starts at 0; If PathIsClear Then While inputByteReaderObj.Read(bytes, 0, bufferSize) > 0 'read bytes consequtively from the input file, each time read bytes equal in length to bufferSize Try My.Computer.FileSystem.WriteAllBytes(outputPath, bytes, True) ' Append to the file contents sucessfullBytes += bufferSize Catch ex As Exception Stop End Try allBytesRead += bufferSize If (allBytesRead + bufferSize) > endofSize Then bufferSize = endofSize - allBytesRead 'change the size of the buffer match the end of the file End If If bufferSize >= 1 Then bytes = New Byte(bufferSize - 1) {} 'the array index starts at zero, the bufferSize starts at 1 End If If allBytesRead >= endofSize Or bufferSize = 0 Then 'the reader has already reached the end of file, exit the reader loop Exit While End If End While If sucessfullBytes = allBytesRead Then SucOpt = True End If End If Else 'write an empty file Try System.IO.File.Create(outputPath) 'Create an empty file because the size of the input file is zero Catch ex As Exception 'an error occured in creating an empty file End Try End If inputByteReaderObj.Close() Return SucOpt End Function