优化C＃中的条件运算符分支

Question

return this.AllowChooseAny.Value ? radioSpecific.Checked ? UserManager.CurrentUser.IsClient ? txtSubject.Text : subjectDropDownList.SelectedItem.Text : String.Empty : UserManager.CurrentUser.IsClient ? txtSubject.Text : subjectDropDownList.SelectedItem.Text;

or in less complex form:

return any ?
    specified ?
       isClient ? textbox : dropdown :
       empty :
    isClient ? textbox : dropdown;

or in schematic form:

                     |
                    any
              /            \
      specified             isClient
      /        \           /        \
  isClient    empty     textbox  dropdown
  /       \
textbox  dropdown

Evidently I have a duplicated block on two different levels. Is it possible to optimize this code to probably split them to one? Or something like that..

Answer 1

That block of code is nearly unreadable. Don't use the ternary operator just for the sake of the ternary operator; it's there to make thigs more readable by eliminating if blocks for very simple expressions. What you have is not.

Answer 2

You can simplify your expression to this:

if (any && !specified)
{
    return empty;
}
else
{
    return isClient ? textbox : dropdown;
}

Answer 3

any && !specified ? 
   empty : 
   isClient ? textbox : dropdown;  

Answer 4

Put the isClient ? textbox : dropdown isClient ? textbox : dropdown block in a method and make method calls from you original branch = no more code duplication.