PropertyGrid control + array of custom objects

Question

I have a PropertyGrid control to which I bind a container with an array of complex objects:

// Collection
public class ParametersCollection
{
    private ParameterObject [] _parameters = null;

    [Category("SubReportParams")]
    public ParameterObject [] Parameters 
    { 
        get { return _parameters; }
        set { _parameters = value; } 
    }

    public ParametersCollection()
    {
        // _parameters initialization here...
    }
}

// Complex object
public class ParameterObject
{
    private string _name = "";
    private string _value = "";

    [Category("Information"), DisplayName("Name")]
    public string Name 
    { 
       get { return _name; } 
       set { _name = value; } 
    }

    [Category("Information"), DisplayName("Value")]
    public string Value 
    { 
       get { return _value; } 
       set { _value = value; } 
    }
}

Everything works fine, except two cases:

1. In example, if array _parameters has only 2 items, default array size is 4 and items with indexes 2 and 3 are nulls. PropertyGrid displays these items as empty fields. How to force PropertyGrid to ignore these fields and simply not displaying it?

2. _parameters variable is an array type, so _parameters items are displayed with their indexes from 0 to n. Is there a posibillity to display them with their names from property ParamObject.Name instead of their indexes from an array?

Answer 1

For the fist question, the easiest way is to add a "fake" property computed from the "real" property. It's not perfect, but you can use various attribute to help:

• DisplayName to give the fake property the name of the real property
• Browsable(false) instructs the property grid to skip the real property

• EditorBrowsable(never) instructs Visual Studio's intellisense to not show this property in external code.

      [Browsable(false)]
      public ParameterObject[] Parameters
      {
          get { return _parameters; }
          set { _parameters = value; }
      }
  
      [Category("SubReportParams"), DisplayName("Parameters")]
      [EditorBrowsable(EditorBrowsableState.Never)]
      public ParameterObject[] NonEmptyParameters
      {
          get
          {
              return _parameters.Where(p => p != null).ToArray();
          }
      }
  

For the second question, one simple way is to add a ToString() implementation like this:

public class ParameterObject
{
    public override string ToString()
    {
        return Name;
    }
}

Otherwise, you can to add a custom TypeConverter to the class.