I have the following code which copies a file to a specific folder and then renames it.
When a file with that name already exists I get the following exception:
Cannot create a file when that file already exists
Is there a way to overwrite the file and rename it? or I should delete the old one and then change the name?
Here is my code:
File.Copy(FileLocation, NewFileLocation, true);
//Rename:
File.Move(Path.Combine(NewFileLocation, fileName), Path.Combine(NewFileLocation, "File.txt"));
Try to use only:
if (File.Exists("newfilename"))
{
System.IO.File.Delete("newfilename");
}
System.IO.File.Move("oldfilename", "newfilename");
One simple option is to delete the file if it exists:
if (System.IO.File.Exists(newFile)) System.IO.File.Delete(newFile);
System.IO.File.Move(oldFile, newFile);
Something like that should work.
You're correct, File.Move will throw an IOException if/when the filename already exists. So, to overcome that you can perform a quick check before the move. e.g.
if (File.Exists(destinationFilename))
{
File.Delete(destinationFilename);
}
File.Move(sourceFilename, destinationFilename);
You should use File.Exists rather than letting the Exception throw. You can then handle if the file should be overwrote or renamed.
Step 1 : as a first step identify wether the file exists or not before copying the file.
using File.Exists() method
Step 2: if the file already exists with same name then delete the existing file using File.Delete() method
Step 3: now copy the File into the new Location using File.Copy() method.
Step 4: Rename the newly copied file.
Try This:
string NewFilePath = Path.Combine(NewFileLocation, fileName);
if(File.Exists(NewFilePath))
{
File.Delete(NewFilePath);
}
//Now copy the file first
File.Copy(FileLocation, NewFileLocation, true);
//Now Rename the File
File.Move(NewFilePath, Path.Combine(NewFileLocation, "File.txt"));
I always use MoveFileEx with the flag MOVEFILE_REPLACE_EXISTING.
Limitations:
It needs to use PInvoke, so it means your code will only work on the Windows platform.
This flag MOVEFILE_REPLACE_EXISTING only work with File(Doesn't work with Folder)
If lpNewFileName or lpExistingFileName name a directory and lpExistingFileName exists, an error is reported.
Related
I've got a folder:
c:\test
I'm trying this code:
File.Move(#"c:\test\SomeFile.txt", #"c:\test\Test");
I get exception:
File already exists
The output directory definitely exists and the input file is there.
What you need is:
if (!File.Exists(#"c:\test\Test\SomeFile.txt")) {
File.Move(#"c:\test\SomeFile.txt", #"c:\test\Test\SomeFile.txt");
}
or
if (File.Exists(#"c:\test\Test\SomeFile.txt")) {
File.Delete(#"c:\test\Test\SomeFile.txt");
}
File.Move(#"c:\test\SomeFile.txt", #"c:\test\Test\SomeFile.txt");
This will either:
If the file doesn't exist at the destination location, successfully move the file, or;
If the file does exist at the destination location, delete it, then move the file.
Edit: I should clarify my answer, even though it's the most upvoted!
The second parameter of File.Move should be the destination file - not a folder. You are specifying the second parameter as the destination folder, not the destination filename - which is what File.Move requires.
So, your second parameter should be c:\test\Test\SomeFile.txt.
You need to move it to another file (rather than a folder), this can also be used to rename.
Move:
File.Move(#"c:\test\SomeFile.txt", #"c:\test\Test\SomeFile.txt");
Rename:
File.Move(#"c:\test\SomeFile.txt", #"c:\test\SomeFile2.txt");
The reason it says "File already exists" in your example, is because C:\test\Test tries to create a file Test without an extension, but cannot do so as a folder already exists with the same name.
Personally I prefer this method.
This will overwrite the file on the destination, removes the source file and also prevent removing the source file when the copy fails.
string source = #"c:\test\SomeFile.txt";
string destination = #"c:\test\test\SomeFile.txt";
try
{
File.Copy(source, destination, true);
File.Delete(source);
}
catch
{
//some error handling
}
You can do a P/Invoke to MoveFileEx() - pass 11 for flags (MOVEFILE_COPY_ALLOWED | MOVEFILE_REPLACE_EXISTING | MOVEFILE_WRITE_THROUGH)
[return: MarshalAs(UnmanagedType.Bool)]
[DllImport("kernel32.dll", SetLastError=true, CharSet=CharSet.Unicode)]
static extern bool MoveFileEx(string existingFileName, string newFileName, int flags);
Or, you can just call
Microsoft.VisualBasic.FileIO.FileSystem.MoveFile(existingFileName, newFileName, true);
after adding Microsoft.VisualBasic as a reference.
With C# on .Net Core 3.0 and beyond, there is now a third boolean parameter:
In .NET Core 3.0 and later versions, you can call Move(String, String, Boolean) setting the parameter overwrite to true, which will replace the file if it exists.
Source: Microsoft Docs
For all other versions of .Net, this answer is the best. Copy with Overwrite, then delete the source file. This is better because it makes it an atomic operation. (I have attempted to update the MS Docs with this)
If file really exists and you want to replace it use below code:
string file = "c:\test\SomeFile.txt"
string moveTo = "c:\test\test\SomeFile.txt"
if (File.Exists(moveTo))
{
File.Delete(moveTo);
}
File.Move(file, moveTo);
According to the docs for File.Move there is no "overwrite if exists" parameter. You tried to specify the destination folder, but you have to give the full file specification.
Reading the docs again ("providing the option to specify a new file name"), I think, adding a backslash to the destination folder spec may work.
Try Microsoft.VisualBasic.FileIO.FileSystem.MoveFile(Source, Destination, True). The last parameter is Overwrite switch, which System.IO.File.Move doesn't have.
If you don't have the option to delete the already existing file in the new location, but still need to move and delete from the original location, this renaming trick might work:
string newFileLocation = #"c:\test\Test\SomeFile.txt";
while (File.Exists(newFileLocation)) {
newFileLocation = newFileLocation.Split('.')[0] + "_copy." + newFileLocation.Split('.')[1];
}
File.Move(#"c:\test\SomeFile.txt", newFileLocation);
This assumes the only '.' in the file name is before the extension.
It splits the file in two before the extension, attaches "_copy." in between.
This lets you move the file, but creates a copy if the file already exists or a copy of the copy already exists, or a copy of the copy of the copy exists... ;)
I believed this to be really simple but somehow i am making a mistake.I am trying to copy one folder to another location
Directory.Move(SourcePath, Destinationpath )
This expression is failing. The exception thrown is "cannot create file that already exists"
Well, you say you want to "copy one folder to another".
Directory.Move(), doesn't copy: as its name implies, it moves a directory. Take at look at the documentation on how to copy files:
.Net 4.0 (see here for an asynchronous approach)
.Net 4.5 (see here for an asynchronous approach)
The Move call is failing because a directory or file in the move operation exists at the specified location (as the exception noted). In order to fix this you need to ensure that no file or directory exists at the destination. The easiest way is to first delete that path
Do not run this function unless you are OK with unconditionally deleting data at DestinationPath.
static void MyMove(string sourcePath, string destPath) {
try {
Directory.Delete(destPath, recursive: true);
} catch {
// Don't care if this fails. If the file didn't exist, great, if the
// file can't be deleted will still get an error in Move. Just try
// Move at this point
}
Directory.Move(sourcePath, destPath);
}
I've got a folder:
c:\test
I'm trying this code:
File.Move(#"c:\test\SomeFile.txt", #"c:\test\Test");
I get exception:
File already exists
The output directory definitely exists and the input file is there.
What you need is:
if (!File.Exists(#"c:\test\Test\SomeFile.txt")) {
File.Move(#"c:\test\SomeFile.txt", #"c:\test\Test\SomeFile.txt");
}
or
if (File.Exists(#"c:\test\Test\SomeFile.txt")) {
File.Delete(#"c:\test\Test\SomeFile.txt");
}
File.Move(#"c:\test\SomeFile.txt", #"c:\test\Test\SomeFile.txt");
This will either:
If the file doesn't exist at the destination location, successfully move the file, or;
If the file does exist at the destination location, delete it, then move the file.
Edit: I should clarify my answer, even though it's the most upvoted!
The second parameter of File.Move should be the destination file - not a folder. You are specifying the second parameter as the destination folder, not the destination filename - which is what File.Move requires.
So, your second parameter should be c:\test\Test\SomeFile.txt.
You need to move it to another file (rather than a folder), this can also be used to rename.
Move:
File.Move(#"c:\test\SomeFile.txt", #"c:\test\Test\SomeFile.txt");
Rename:
File.Move(#"c:\test\SomeFile.txt", #"c:\test\SomeFile2.txt");
The reason it says "File already exists" in your example, is because C:\test\Test tries to create a file Test without an extension, but cannot do so as a folder already exists with the same name.
Personally I prefer this method.
This will overwrite the file on the destination, removes the source file and also prevent removing the source file when the copy fails.
string source = #"c:\test\SomeFile.txt";
string destination = #"c:\test\test\SomeFile.txt";
try
{
File.Copy(source, destination, true);
File.Delete(source);
}
catch
{
//some error handling
}
You can do a P/Invoke to MoveFileEx() - pass 11 for flags (MOVEFILE_COPY_ALLOWED | MOVEFILE_REPLACE_EXISTING | MOVEFILE_WRITE_THROUGH)
[return: MarshalAs(UnmanagedType.Bool)]
[DllImport("kernel32.dll", SetLastError=true, CharSet=CharSet.Unicode)]
static extern bool MoveFileEx(string existingFileName, string newFileName, int flags);
Or, you can just call
Microsoft.VisualBasic.FileIO.FileSystem.MoveFile(existingFileName, newFileName, true);
after adding Microsoft.VisualBasic as a reference.
With C# on .Net Core 3.0 and beyond, there is now a third boolean parameter:
In .NET Core 3.0 and later versions, you can call Move(String, String, Boolean) setting the parameter overwrite to true, which will replace the file if it exists.
Source: Microsoft Docs
For all other versions of .Net, this answer is the best. Copy with Overwrite, then delete the source file. This is better because it makes it an atomic operation. (I have attempted to update the MS Docs with this)
If file really exists and you want to replace it use below code:
string file = "c:\test\SomeFile.txt"
string moveTo = "c:\test\test\SomeFile.txt"
if (File.Exists(moveTo))
{
File.Delete(moveTo);
}
File.Move(file, moveTo);
According to the docs for File.Move there is no "overwrite if exists" parameter. You tried to specify the destination folder, but you have to give the full file specification.
Reading the docs again ("providing the option to specify a new file name"), I think, adding a backslash to the destination folder spec may work.
Try Microsoft.VisualBasic.FileIO.FileSystem.MoveFile(Source, Destination, True). The last parameter is Overwrite switch, which System.IO.File.Move doesn't have.
If you don't have the option to delete the already existing file in the new location, but still need to move and delete from the original location, this renaming trick might work:
string newFileLocation = #"c:\test\Test\SomeFile.txt";
while (File.Exists(newFileLocation)) {
newFileLocation = newFileLocation.Split('.')[0] + "_copy." + newFileLocation.Split('.')[1];
}
File.Move(#"c:\test\SomeFile.txt", newFileLocation);
This assumes the only '.' in the file name is before the extension.
It splits the file in two before the extension, attaches "_copy." in between.
This lets you move the file, but creates a copy if the file already exists or a copy of the copy already exists, or a copy of the copy of the copy exists... ;)
When modifying and saving a file, how to leave a copy of the original file, say give it *.bak?Is there a built-in support?
You could use the .NET framework to simply copy the file to a .bak and then modify the original.
You can call File.Move to rename the original file, then save the new version with the original name.
Here is a short example:
// This is the current file
string filePath = #"C:\temp\test.txt";
//Now change file extension to text.bak
string filePathBak = Path.ChangeExtension(filePath, "bak");
// Save orginal file
File.Move(filePath, filePathBak);
I am using the FileInfo class. However, the file info cannot find the file.
The file is called log4Net.config and I have added it to my project. I have set the properties to build action = 'Content' and copy output = 'copy always'
When I run the following code:
FileInfo logfileInfo = new FileInfo("Log4Net.config");
if (!logfileInfo.Exists)
{
Console.WriteLine("Cannot find file: " + logfileInfo.FullName);
return;
}
else
{
XmlConfigurator.Configure(logfileInfo);
}
Exists is always false. The exception is: Could not find file 'Log4Net.config'.
I have checked on my PDA and the Log4Net.config has been copied the PDA and is in the same directory as the executable. So not sure why it cannot find it.
Just some extra info the configure method expects a FileInfo as a parameter.
Am I doing something wrong.
Many thanks for any advice,
Steve
You have to point to the root of your project. FileInfo points to the root of the OS not the root of the exe. So you should change the code like this :
FileInfo logfileInfo = new FileInfo(Path.GetDirectoryName(Assembly.GetExecutingAssembly().GetName().CodeBase) + #"\Log4Net.config");
A file not found exception is also thrown when the program does not have the security permission to access the file, so perhaps that's the case?
btw, there's a contradiction in your Post: First you say the file is called "logPDA.config", then it's suddenly called "Log4Net.config". Just to make sure, is the file always named the same?
You are assuming that the Program Folder is the current directory. Afaik that is not the case. You can investigate starting with System.IO.Directory.GetCurrentDirectory()
string logIOFilePath =
Path.Combine(Path.GetDirectoryName(Assembly.GetExecutingAssembly().GetName().CodeBase),
"Log4Net.config");