Get/Set Method for Array Properties

Question

I have an Entry class, through which i want to expose data to a Gridview in WPF (via an List<Entry>). I need to have a column in the Gridview for every property of the Entry object (also get one column for every entry of propsA3), but I am uncertain how to define the getter/setter methods for the array in order to always get/set the properties of the underlying data.

public Entry
{
  private ObjA oA;
  private ObjB[] listB;

  public int PropA1 {get {return oA.Prop1;} set {oA.Prop1 = value;}}
  public int PropA2 {get {return oA.Prop2;} set {oA.Prop1 = value;}}
  public int[] propsA3;
}

public ObjA
{
   public int Prop1 {get, set};
   public int Prop2 {get, set};

   public int getVal3(ObjB b) {return calSomethin(b);}
   public int setVal3(ref ObjB b, int val) { /*do something to ObjB*/}
}

public ObjB
{
   Byte[] data;
}

What I want for PropsA3 have a get/set behavior of the following:

Entry e;

Get: int a = e.propsA3[i]; => a = oA.getVal3(listB[i]);

Set: e.propsA3[i] = 5; => oA.setVal3(listB[i], val);

Is this possible? How can achieve this or how do I have to change the class design to get the desired result?

score 1 · Answer 1 · answered Jun 26 '13 at 12:36

It is possible, but I'm not sure what the benefit would be, you can do it using a wrapper class.. eg:

public class Entry
{
    private ObjA oA;
    private ObjB[] listB;

    public int PropA1 {get {return {oA.Prop1}} set {oA.Prop1 = value;}}
    public int PropA2 {get {return {oA.Prop2}} set {oA.Prop1 = value;}}
    public EntryProperties propsA3;

    public Entry() 
    {
        propsA3 = new EntryProperties(this);
    }

    public class EntryProperties 
    {
        private Entry _entry;

        public EntryProperties(Entry entry) {
            _entry = entry;
        }

        public int this[int index] {
            get { return _entry.oA.getVal3(_entry.listB[index]); }
            set { _entry.oA.setVal3(_entry.listB[index], value); }
        }
    }
}

Having said that, I really don't think it's a good idea - why not define a view model class with the properties you want in the grid and then either set those manually, or use something like AutoMapper or ValueInjector to do so...

Thanks for the answer. I'm not set on having to access `e.propsA3[i]` but I thought my view model will have a `List — kiki, Jun 26 '13 at 13:05
If you know what the properties will be, then I'd suggest adding them all explicitly, or if that's not really what you want, maybe look at using a DataTable or other Dictionary equivalent — Martin Ernst, Jun 26 '13 at 13:15

score 1 · Answer 2 · answered Jun 26 '13 at 12:38

This should work

pulbic Entry 
{
    public ObjA propsA3 { get; set; }
}

public ObjA
{
   public int Prop1 {get, set};
   public int Prop2 {get, set};

   public int this[ObjB b]
   {
      get { return getVal(b); }
      set { /* do something*/ }
   }

   private int getVal3(ObjB b) {return calSomethin(b);}
   private int setVal3(ref ObjB b, int val) { /*do something to ObjB*/}
}

Get/Set Method for Array Properties

2 Answers2

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