How to lock a file with C#?

Question

I\'m not sure what people usually mean by \"lock\" a file, but what I want is to do that thing to a file that will produce a \"The specified file is in use\" error message w

Answer 1

While FileShare.None is undoubtedly a quick and easy solution for locking a whole file you could lock part of a file using FileStream.Lock()

public virtual void Lock(
    long position,
    long length
)

Parameters

position
    Type: System.Int64
    The beginning of the range to lock. The value of this parameter must be equal to or greater than zero (0). 

length
    Type: System.Int64
    The range to be locked. 

and conversely you could use the following to unlock a file: FileStream.Unlock()

public virtual void Unlock(
    long position,
    long length
)

Parameters

position
    Type: System.Int64
    The beginning of the range to unlock. 

length
    Type: System.Int64
    The range to be unlocked.