C# Why does System.IO.File.Exists keep coming up false? - c#

string profile = "\\" + txtProfileLoad.Text + ".txt";
profile = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments) + profile;
The variable profile is receiving the correct file path, but when I run it the File.Exists comes up false every time.
if (System.IO.File.Exists(profile) == true)
{
System.IO.StreamReader profileReader;
profileReader = new System.IO.StreamReader(profile);
do
{
profileLevel = profileLevel + profileReader.ReadLine() + "\r\n";
} while (profileReader.Peek() != -1);
loadName(profileLevel);
wordBeingUsed.finalWord = loadedName;
Close();
}
else
{
MessageBox.Show("Invalid file name. Please try again.");
}
There aren't any permissions stopping it from seeing the file.
Any help with this would be appreciated. It's been driving me crazy.

Is this a pre-existing file that you are trying to read? Or is this a new file that you are hoping to create? What is the value inside txtProfileLoad.Text, issue most likely is within this property.
Run a sanity check:
var profile = "mytestfile.txt";
var myFile = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments), profile);
File.WriteAllText(myFile, "Testing file write");
if (File.Exists(myFile))
{
// Access works.
}
else
{
//Didn't work
}
If above code works, then it is most likely that the name you create from txtProfileLoad.Text is different from actual file on the drive. On the other hand, if this is a file that doesn't exist yet; then of course it would return false when you check Exists.

You can use a string variable and pass the file name to it:
string tempFile = txtProfileLoad.Text;
string profile = #"C:\temp\tempfile.txt";
Also check out if you could use the file open method instead of File.Exist.

As per MSDN:
true if the caller has the required permissions and path contains the name of an existing file; otherwise, false. This method also
returns false if path is Nothing, an invalid path, or a zero-length
string. If the caller does not have sufficient permissions to read the
specified file, no exception is thrown and the method returns false
regardless of the existence of path.
Have you tried running as an administrator? Try do "right click" on the Visual Studio icon and select "Run as Administrator", and see if you still encounter the same behaviour.

Related

File.Exists(file) is false but file exist

I'm add a file in one controller and in another controller I want check if the file is exist. I' using File.Exist(file), but it's always false, even if the file exist...
I adding file, and image is added successful.
if ((image!= null & image.ContentLength > 0))
{
string name = event.EventId.ToString() + ".jpg";
var fileName = name;
var path = Path.Combine(Server.MapPath("~/App_Data/Plakaty"), fileName);
plakat.SaveAs(path);
}
I'm checking in another controller if this file exist:
string file = "~/App_Data/Plakaty/" + wyd.EventId.ToString() + ".jpg";
ViewBag.file_exist = System.IO.File.Exists(file); //always is false
And my View: (It's returning only "No file")
#if (ViewBag.file_exist == true)
{
<p>File exist</p>
}
else
{
<p>No file</p>
}
You need to do the Server.MapPath again when checking the file and do the forward slash.
string file = Server.MapPath("~") + #"\App_Data\Plakaty\"
+ wyd.EventId.ToString() + ".jpg";
ViewBag.file_exist = System.IO.File.Exists(file ); //always is false
You forgot to write Server.MapPath when checking if file exist
Have you checked permissions?
The Exists method returns false if any error occurs while trying to determine if the specified file exists. This can occur in situations that raise exceptions such as passing a file name with invalid characters or too many characters, a failing or missing disk, or if the caller does not have permission to read the file. See documentation
However most likely is what #Obama answered about the path being wrong as you didn't call Server.MapPath

File is not created after another has been created

I am trying to create 2 XML files in the same folder.
For some reason it does create the first one, but does not create the second one.
Could it be that the first one is still being created when an attempt to create the second file is made, and therefore the latter fails?
I don't get any errors with the code:
if (File.Exists(FileNameTextBox.Text + ".AA.xml"))
{
MessageBox.Show("Already exists. renaming to *.old" + Environment.NewLine +
"if there is already an *.old file, this will be deleted.");
if (File.Exists(FileNameTextBox.Text + ".AA.xml.old"))
{
File.Delete(FileNameTextBox.Text + ".AA.xml.old");
}
File.Move(FileNameTextBox.Text + ".AA.xml", FileNameTextBox.Text + ".AA.xml.old");
}
if (!File.Exists(FileNameTextBox.Text + ".AA.xml"))
{
XmlTextWriter textWritter = new XmlTextWriter(FileNameTextBox.Text + ".AA.xml", null);
textWritter.WriteStartDocument();
textWritter.WriteStartElement("Data");
textWritter.WriteEndElement();
textWritter.Close();
}
if (File.Exists("BB.xml"))
{
if (File.Exists("BB.xml.old"))
{
File.Delete("BB.xml.old");
}
File.Move("BB.xml", "BB.xml.old");
}
if (!File.Exists("BB.xml"))
{
XmlTextWriter textWritterPC3 = new XmlTextWriter("BB.xml", null);
textWritterPC3.WriteStartDocument();
textWritterPC3.WriteStartElement("Data");
textWritterPC3.WriteEndElement();
textWritterPC3.Close();
}
Whats in FileNameTextBox.Text? Does it specify a directory path?
Your second file is created without saying which directory. So it will be created in the current directory - which is not necessarily the directory specified by FileNameTextBox.Text
You are not specifying an absolute path for your file names, so you are using whatever the current directory happens to be, which is not reliable. Also you may need to call DirectoryInfo.Refresh() or FileInfo.Refresh() to make sure you are seeing the latest directory information (whether the file exists or not).
The comment is only making the last if case execute the first row.. The last if should look like this. I don't know if it's only in your example.
Your example
if (!File.Exists("BB.xml")) // {
XmlTextWriter textWritterPC3 = new XmlTextWriter("BB.xml", null);
should be
if (!File.Exists("BB.xml")) //
{
XmlTextWriter textWritterPC3 = new XmlTextWriter("BB.xml", null);
textWritterPC3.WriteStartDocument();
textWritterPC3.WriteStartElement("Data");
textWritterPC3.WriteEndElement();
textWritterPC3.Close();
}

Opening a txt file automatically using OnSelectedIndexChanged

What I am trying to do is to read in a file to a richTextBox automatically with the OnSelectedIndexChange method. There arent any errors, it just flat out doesnt work. Heres the code that I am working with
public void comboBox1_OnSelectedIndexChanged(object sender, EventArgs e)
{
string selectedPath = comboBox1.SelectedItem.ToString();
if (File.Exists(#"C:\\Mavro\\MavBridge\\" + selectedPath + "\\ " + "Comment" + ".txt"))
{
try
{
Thread.Sleep(0500);
System.IO.StreamReader textFile = new System.IO.StreamReader(#"C:\\Mavro\\MavBridge\\" + selectedPath + "\\ " + "Comment" + ".txt");
richTextBox1.Text = textFile.ReadToEnd();
textFile.Close();
}
catch
{
MessageBox.Show("Error: File cannot be opened!", "Error");
}
}
else
{
MessageBox.Show("No comment was found in this folder", "Alert");
}
}
Just for fun, lets have you try something. First, replace the following line:
if (File.Exists(#"C:\\Mavro\\MavBridge\\" + selectedPath + "\\ " + "Comment" + ".txt"))
with this:
if(File.Exists(string.Format("C:\\Mavro\\MavBridge\\{0}\\Comment.txt", selectedPath)))
It looks like you had an extra space ("\\ " + "Comment"), so I'm sure that's why it never hits this block of code. Also, anytime you have an object that needs to be closed/disposed, more often than not it implements IDisposable, meaning you should encapsulate the object within a using block:
Thread.Sleep(0500);
try
{
using(System.IO.StreamReader textFile = new System.IO.StreamReader(string.Format("C:\\Mavro\\MavBridge\\{0}\\Comment.txt", selectedPath)))
{
richTextBox1.Text = textFile.ReadToEnd();
}
}
catch
{
MessageBox.Show("Error: File cannot be opened!", "Error");
}
However, this can be simplified even further by bypassing the StreamReader entirely and using System.IO.File.ReadAllText instead:
richTextBox1.Text = System.IO.File.ReadAllText(string.Format("C:\\Mavro\\MavBridge\\{0}\\Comment.txt", selectedPath));
Well, one problem comes from the fact that you have:
#"C:\\Mavro\\MavBridge\\" + selectedPath + "\\ " + "Comment" + ".txt"
Since you are using a verbatim string (the # at the beginning), you do not need to put double slashes.
For the rest, make sure your file exists.
Later edit: also I am not sure if you copy/pasted in a rush or something like that, but did you actually put the catch block inside the try ?
1) What is the error you see?
2) Are you positive the file exists?
3) Are you positive the path created by your code is the path you are expecting?
4) Why are you sleeping the thread?
5) Why not just use File.ReadAllText?
6) File.Exists will return false if the code is running with permissions that do not have access to a file, even if the file does exist. Does the user your code is running as, have permissions?
true if the caller has the required permissions and path contains the
name of an existing file; otherwise, false. This method also returns
false if path is null, an invalid path, or a zero-length string. If
the caller does not have sufficient permissions to read the specified
file, no exception is thrown and the method returns false regardless
of the existence of path.
and
The Exists method returns false if any error occurs while trying to
determine if the specified file exists. This can occur in situations
that raise exceptions such as passing a file name with invalid
characters or too many characters, a failing or missing disk, or if
the caller does not have permission to read the file.
Get rid of # before each string. Your directory as it currently is uses actual double slashes instead of C:\Mavro\MavBridge. Use single slashes with \ or go with # at the beginning, but don't use both.
Also, I would strongly suggest using Path.Combine instead of concatenating pieces together like that.

Check if a file exists on the server

I am trying to check if a file is on the server with the C# code behind of my ASP.NET web page. I know the file does exist as I put it on the server in a piece of code before hand. Can anyone see why it is not finding the file. This is the code:
wordDocName = "~/specifications/" + Convert.ToInt32(ViewState["projectSelected"]) + ".doc";
ViewState["wordDocName"] = wordDocName;
if (File.Exists(wordDocName))
{
btnDownloadWordDoc.Visible = true;
}
else
{
btnDownloadWordDoc.Visible = false;
}
the file path should be physical not virtual. Use
if (File.Exists(Server.MapPath(wordDocName)))
File.Exists() and probably everything else you want to do with the file will need a real Path.
Your wordDocName is a relative URL.
Simply use
string fileName = Server.MapPath(wordDocName);
Use
Server.MapPath("~/specifications/" + Convert.ToInt32(ViewState["projectSelected"]) + ".doc")
to get the fully-qualified path. That should do the trick for ya.
You need to use Server.MapPath e.g.
wordDocName = Server.MapPath("~/specifications/" + Convert.ToInt32(ViewState["projectSelected"]) + ".doc");
ViewState["wordDocName"] = wordDocName;
if (File.Exists(wordDocName))
{
btnDownloadWordDoc.Visible = true;
}
else
{
btnDownloadWordDoc.Visible = false;
}
this might not work if the directory holding the file is referenced by a junction/symbolic link. I have this case in my own application and if I put the REAL path to the file, File.Exists() returns true. But if I use Server.MapPath but the folder is in fact a junction to the folder, it seems to fail. Anyone experienced the same behaviour?
The character "~" is a special char in ASP.NET to get virtual path specifications and simply means "root directory of the application". Is is not understood by the .NET BCL like the File API and must be mapped first into a physical path with Server.MapPath() as others stated.
You have to convert the path to a physical path with Server.MapPath(relativePath)
if (File.Exists(filePath))
wordDocName = "~/specifications/" + ViewState["projectSelected"] + ".doc";
btnDownloadWordDoc.Visible = File.Exists(Server.MapPath(wordDocName));
string docname="traintatkalantnoy.txt";
string a = (Server.MapPath(docname));
if (File.Exists(a))

Getting an exception as "The parameter is incorrect.\r\n" while moving file

I have written a code to move a file as follows
private void Move_Click(object sender, EventArgs e)
{
string strOrgpath = string.Empty, strNewpath = string.Empty;
strOrgpath = tvwACH.SelectedNode.ToString();
string strPath = strOrgpath.Substring(10);
FolderBrowserDialog folderborwser1 = new FolderBrowserDialog();
if (folderborwser1.ShowDialog() == DialogResult.OK)
{
try
{
strNewpath = folderborwser1.SelectedPath;
File.Move(strPath, strNewpath);
}
catch (Exception ex)
{
}
}
}
But i am getting the exception as i mentioned can any one tell why and some times i am getting the error as access to the path is denied
Make sure your substring call returns the correct result. If possible, use static methods from the Path class instead. Take a look at the MSDN page for File.Move and pay attention to what parameters are expected -- you should provide two valid full file names (e.g. C:\Blah\myFile.txt).
"Access denied" error message might happen if the user picks a folder they don't have write access to in the folder browser dialog. That's a scenario you'll have to handle in your code, perhaps by catching the UnauthorizedAccessException.
Update: the destination file should also point to a filename. So you'll need to do something like this:
var origFileName = Path.GetFileName(strPath);
strNewpath = Path.Combine(folderborwser1.SelectedPath, origFileName);
File.Move(strPath, strNewpath);
Without seeing the values that are being used in your application at run-time, I'm guessing tvwACH.SelecteNode.ToString() or strOrgpath.Substring(10) is not a valid File System path.
You should Debug your application and set a breakpoint to see what those values are (and post them if it's not obvious what your problem is at that point).

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