How to remove a single Attribute (e.g. ReadOnly) from a File?

Question

Let say, a file has the following attributes: ReadOnly, Hidden, Archived, System. How can I remove only one Attribute? (for example ReadOnly)

Answer 1

/// 

/// Addes the given FileAttributes to the given File.
/// It's possible to combine FileAttributes: FileAttributes.Hidden | FileAttributes.ReadOnly
/// 
public static void AttributesSet(this FileInfo pFile, FileAttributes pAttributes)
{
    pFile.Attributes = pFile.Attributes | pAttributes;
    pFile.Refresh();
}

/// 

/// Removes the given FileAttributes from the given File.
/// It's possible to combine FileAttributes: FileAttributes.Hidden | FileAttributes.ReadOnly
/// 
public static void AttributesRemove(this FileInfo pFile, FileAttributes pAttributes)
{
    pFile.Attributes = pFile.Attributes & ~pAttributes;
    pFile.Refresh();
}

/// 

/// Checks the given File on the given Attributes.
/// It's possible to combine FileAttributes: FileAttributes.Hidden | FileAttributes.ReadOnly
/// 
/// True if any Attribute is set, False if non is set
public static bool AttributesIsAnySet(this FileInfo pFile, FileAttributes pAttributes)
{
    return ((pFile.Attributes & pAttributes) > 0);
}

/// 

/// Checks the given File on the given Attributes.
/// It's possible to combine FileAttributes: FileAttributes.Hidden | FileAttributes.ReadOnly
/// 
/// True if all Attributes are set, False if any is not set
public static bool AttributesIsSet(this FileInfo pFile, FileAttributes pAttributes)
{
    return (pAttributes == (pFile.Attributes & pAttributes));
}

Example:

private static void Test()
{
    var lFileInfo = new FileInfo(@"C:\Neues Textdokument.txt");
    lFileInfo.AttributesSet(FileAttributes.Hidden | FileAttributes.ReadOnly);
    lFileInfo.AttributesSet(FileAttributes.Temporary);
    var lBool1 = lFileInfo.AttributesIsSet(FileAttributes.Hidden);
    var lBool2 = lFileInfo.AttributesIsSet(FileAttributes.Temporary);
    var lBool3 = lFileInfo.AttributesIsSet(FileAttributes.Encrypted);
    var lBool4 = lFileInfo.AttributesIsSet(FileAttributes.ReadOnly | FileAttributes.Temporary);
    var lBool5 = lFileInfo.AttributesIsSet(FileAttributes.ReadOnly | FileAttributes.Encrypted);
    var lBool6 = lFileInfo.AttributesIsAnySet(FileAttributes.ReadOnly | FileAttributes.Temporary);
    var lBool7 = lFileInfo.AttributesIsAnySet(FileAttributes.ReadOnly | FileAttributes.Encrypted);
    var lBool8 = lFileInfo.AttributesIsAnySet(FileAttributes.Encrypted);
    lFileInfo.AttributesRemove(FileAttributes.Temporary);
    lFileInfo.AttributesRemove(FileAttributes.Hidden | FileAttributes.ReadOnly);
}