How to lock/unlock a field at runtime in C#?

Question

Can I lock/unlock fields or objects at runtime against writing? In other words something like changing objects to read-only temporarily at runtime...

For example:

int x = 5; // x is 5  
LockObject(x);  
x = 7; // no change  
UnlockObject(x);  
x = 10; // x is 10

if not can you give me some possible solutions?

Answer 1

Wrap it in a property and then use a boolean flag as the "lock".

You can also use a struct to handle this type of logic.

public struct LockableInt
{
    private int _value;
    public bool Locked;

    public void Lock(bool locked) {Locked = locked;}

    public int Value
    {
        get 
        { return _value; }
        set 
        { if (!Locked) _value = value; }
    }

    public override string ToString()
    {
        return _value.ToString();
    }
}

Sample client code:

public static void RunSnippet()
{
    LockableInt li = new LockableInt();
    li.Value = 5;
    Console.WriteLine(li.ToString());
    li.Lock(true);
    li.Value = 6;
    Console.WriteLine(li.ToString());
    li.Lock(false);
    li.Value = 7;
    Console.WriteLine(li.ToString());

}

Output:

5 5 7 Press any key to continue...

Answer 2

You can use accessors to do this...

public class X
{
    private bool locked = false;

    private int lockedVar;
    public int LockedVar
    {
        get { return lockedVar; }
        set { if (!locked) lockedVar = value; }
    }

    public void LockObject() { locked = true; }
    public void UnlockObject() { locked = false; }
}

Answer 3

Thanks all for help. Here is a more generalized alternative.
I have decided that it would be more convenient to use freeze/unfreeze since lock/unlock exists in the context of multithreading programming.

public class FreezeableValue<T>  
{  
 private bool frozen;  
 private T value;

 public FreezeableValue()
 {
    frozen = false;
 }

 public FreezeableValue(T value)
 {
    this.value = value;
    frozen = false;
 }

 public void Freeze(bool frozen)
 {
    this.frozen = frozen;
 }

 public T Value
 {
    get { return value; }
    set
    {
        if (!frozen) this.value = value;
    }
 }
}