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Figure 9-11. MemberwiseClone() returns a shallow copy of the current object.

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In order for your Clone() method to make a complete deep copy of the internal reference

types, you need to configure the object returned by MemberwiseClone() to account for the current

point’s name (the System.Guid type is in fact a structure, so the numerical data is indeed copied).

Here is one possible implementation:

// Now we need to adjust for the PointDescription member.

public object Clone()

{

// First get a shallow copy.

Point newPoint = (Point)this.MemberwiseClone();

// Then fill in the gaps.

PointDescription currentDesc = new PointDescription();

currentDesc.petName = this.desc.petName;

newPoint.desc = currentDesc;

return newPoint;

}

If you rerun the application once again as shown in Figure 9-12, you see that the Point

returned from Clone() does copy its internal reference type member variables (note the pet name

is now unique for both p3 and p4).

Figure 9-12.

Now you have a true deep copy of the object.

To summarize the cloning process, if you have a class or structure that contains nothing but

value types, implement your Clone() method using MemberwiseClone(). However, if you have a cus-

tom type that maintains other reference types, you need to establish a new type that takes into

account each reference type member variable.