检查对象中的任何一个是否为空并继续处理其他对象

Question

I have a list like as this below in a class

public class DesignHubProject{
   public List<ProjectObject<HydronicSystem>> HydronicSystems { get; set; }
}

here is the object that ProjectObject<HydronicSystem> is holding

public class ProjectObject<T>
{
    public Guid? Id { get; set; }
    public T OriginalObject { get; set; }
    public T ModifiedObject { get; set; }
}

Now i need to find if modified object is null i need to proceed with the original object or if it is not null use modified object it self.

for this i am looping through the object like as below

    foreach(var item in designHubProject.HydronicSystems)
    {
           // here i need to check for modified object is null proceed with original object and 
            // if original object is null proceed with modified object           
    }

how can i check the object proceed with that, Could any one please suggest any idea on this that would be very grateful to me.

Thanks in advance.

Answer 1

One way is to use Extension method (usefull for code reuse):

public static class ProjectObjectExtension
{
    public static T GetObject<T>(this ProjectObject<T> projectObject)
        => projectObject.ModifiedObject ?? projectObject.OriginalObject;

    // or like @MichaelRandall suggests in his answer
    public static T GetObjectMichaelRandallWay<T>(this ProjectObject<T> projectObject)
        => EqualityComparer<T>.Default.Equals(projectObject.ModifiedObject, default) ?
            projectObject.OriginalObject :
            projectObject.ModifiedObject;
}

Then just call this method:

foreach(var item in designHubProject.HydronicSystems)
{
    var obj = item.GetObject();
    // rest of your code...
}

Or just call this code within your loop:

foreach(var item in designHubProject.HydronicSystems)
{
    var obj = item.ModifiedObject ?? item.OriginalObject;
    // rest of your code...
}

You may also use LINQ .Select() method:

foreach(var obj in designHubProject.HydronicSystems.Select(p => p.ModifiedObject ?? p.OriginalObject))
{
    // rest of your code...
}