Unable to copy a file from one directory to application folder

Question

I am writing ac# desktop app where I want users to select a file from open file dialog after which the program will copy the file to where the application is executing from: here is my code that is not working at the moment

var dlg = new Microsoft.Win32.OpenFileDialog { 
    Title           = "Select File", 
    DefaultExt      = ".json", 
    Filter          = "Json File (.json)|*.json", 
    CheckFileExists = true 
};

if (dlg.ShowDialog() == true)
{
    try
    {
        var currentDirectory = System.Windows.Forms.Application.ExecutablePath;
        var destFile = Path.Combine(currentDirectory + "/temp/", dlg.FileName);

        File.Copy(dlg.FileName, destFile, true);
    }
    catch (Exception ex)
    {
        MessageBox.Show(string.Format("An error occured: " + ex.Message));
    }
}

Now I am getting the error that

the file is being used by another program

. When I edit the code that is meant to initiate the copy by removing true:

File.Copy(dlg.FileName, destFile);

I get the error that the

file already exists

in the directory where it is being selected from.

Answer 1

It seems, that you have an incorrect path to write into.

 System.Windows.Forms.Application.ExecutablePath

returns exe file itself, not directory. Try

 var destFile = Path.Combine(
   Path.GetDirectoryName(Application.ExecutablePath), // Exe directory
  "temp",                                             // + Temp subdirectory
   Path.GetFileName(dlg.FileName));                   // dlg.FileName (without directory)

If you aren't sure that temp exists, you have to create it:

 Directory.CreateDirectory(Path.GetDirectoryName(destFile));

Answer 2

Use below Code for Copy file from one folder to another folder.

string[] filePaths = Directory.GetFiles("Your Path");
    foreach (var filename in filePaths)
    {
        string file = filename.ToString();

        //Do your job with "file"

        string str = "Your Destination"+file.ToString(),Replace("Your Path");
        if (!File.Exists(str))
        {
            File.Copy(file , str);
        }
    }