Assigning a value to a property from one class to another

Question

Hi,

I am working in wpf-mvvm pattern.In that I have two classes.I need to assign a value to one property in a class, from the value of property in another class. Help me to solve this.

Example

public class A

{

 DateTime _NeedByDateHeader;

public DateTime NeedByDateHeader

{

get

{

return _NeedByDateHeader;

}

set

{

_NeedByDateHeader = value;

NotifyPropertyChanged("NeedByDateHeader");

}

}

 

public Class B{

 DateTime _NeedByDateLine ;

public DateTime NeedByDateLine

{

get

{

return _NeedByDateLine;

}

set

{

_NeedByDateLine = value;

NotifyPropertyChanged("NeedByDateLine");

}

}}

 

Here I need to assign NeedByDateHeader value to NeedByDateLine.If both properties in same class i can handle.But it is in two different classes. So help me.