How to make a read-only file?

Question

I am using the C # StreamWritier class. Questions:

• How to make a file read-only so that no one can delete or write it?
• How to create a hidden file?

I create the file as follows:

  private void button1_Click(object sender, EventArgs e) { SaveFileDialog save = new SaveFileDialog(); save.FileName = textBox1.Text; save.Filter = "Text File | *.rtf"; if (save.ShowDialog() == DialogResult.OK) { StreamWriter writer = new StreamWriter(save.OpenFile()); writer.WriteLine(textBox2.Text); } writer.Dispose(); writer.Close(); } 

Answer 1

Hello, you can try using this method.

1

  public static void SetFileReadAccess(string FileName, bool SetReadOnly) { FileInfo fInfo = new FileInfo(FileName); // Set the IsReadOnly property. fInfo.IsReadOnly = SetReadOnly; } 

2

 File.SetAttributes(yourFilePath, FileAttributes.Hidden); 

......

Answer 2

You can set the ReadOnly attribute using File.SetAttributes .

Example:

 File.SetAttributes(textBox1.Text, FileAttributes.ReadOnly); 

Note that this only sets the readonly flag, it does not modify the NTFS access control lists (which means that every qualified user can remove the read-only attribute). Also note that this resets all other attributes of the file, which should not be a problem in your case, since you are creating a new file anyway. If you need to keep existing attributes, first use File.GetAttributes and combine the existing flags with the new one (see the Example in the linked MSDN page).

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If you need to protect your file from malicious write attempts, you must understand NTFS security (google for "NTFS security" for a lot of resources). Once you understand this, the following question will tell you how to change them in C #:

• Configuring NTFS Permissions in C # .NET

Answer 3

Use this for a read-only file:

 FileAttributes yourFile = File.GetAttributes(yourFilePath); File.SetAttributes(yourFilePath, FileAttributes.ReadOnly); 

Where "yourFilePath" is the string.

For a hidden file:

 FileAttributes yourFile = File.GetAttributes(yourFilePath); File.SetAttributes(yourFilePath, FileAttributes.Hidden); 

And for a regular file (not only for reading, not hidden):

 FileAttributes yourFile = File.GetAttributes(yourFilePath); File.SetAttributes(yourFilePath, FileAttributes.Normal); 

I know that you did not ask to install a normal file, but I think it is useful to know.