Propertygrid: How to display combo with icons for enum type?

We need to cretate new type inhereted from UITypeEditor with custom painting( in our case the images located in resource file - where each image name equals to memeber of the enum ) as shown below

 

public class CountryEditor : UITypeEditor
{
    ///<summary>
    ///Indicates whether the specified context supports 
    /// painting a representation of an object's value within the specified context.
    ///</summary>
    ///
    ///<returns>
    ///true if 
    /// <see cref="M:System.Drawing.Design.UITypeEditor.PaintValue(System.Object,System.Drawing.Graphics,System.Drawing.Rectangle)">
    /// </see> is implemented; otherwise, false.
    ///</returns>
    ///
    ///<param name="context">An <see cref="T:System.ComponentModel.ITypeDescriptorContext">
    /// </see> that can be used to gain additional context information. </param>
    public override bool GetPaintValueSupported(ITypeDescriptorContext context)
    {
        return true;
    }

    ///<summary>
    ///Paints a representation of the value of an 
    /// object using the specified <see cref="T:System.Drawing.Design.PaintValueEventArgs"></see>.
    ///</summary>
    ///
    ///<param name="e">A <see cref="T:System.Drawing.Design.PaintValueEventArgs">
    /// </see> that indicates what to paint and where to paint it. </param>
    public override void PaintValue(PaintValueEventArgs e)
    {
        string resourcename = Enum.GetName(typeof (Country), e.Value);

        // retrive  image from resource file
        Bitmap countryImage =
          (Bitmap)Resources.ResourceManager.GetObject(resourcename);
        Rectangle destRect = e.Bounds;
        countryImage.MakeTransparent();

        // paint
        e.Graphics.DrawImage(countryImage, destRect);

    }
}

 

Create new EnumTypeConverter

public class EnumTypeConverter : EnumConverter
{
    private Type _enumType;
    public EnumTypeConverter(Type type)
        : base(type)
    {
        _enumType = type;
    }

    public override bool CanConvertTo(ITypeDescriptorContext context,
      Type destType)
    {
        return destType == typeof(string);
    }

    public override object ConvertTo(ITypeDescriptorContext context,
      CultureInfo culture,
      object value, Type destType)
    {
        FieldInfo fi = _enumType.GetField(Enum.GetName(_enumType, value));
        DescriptionAttribute dna =
          (DescriptionAttribute)Attribute.GetCustomAttribute(
            fi, typeof(DescriptionAttribute));

        if (dna != null)
            return dna.Description;
        else
            return value.ToString();
    }

    public override bool CanConvertFrom(ITypeDescriptorContext context,
      Type srcType)
    {
        return srcType == typeof(string);
    }

    public override object ConvertFrom(ITypeDescriptorContext context,
      CultureInfo culture,
      object value)
    {
        foreach (FieldInfo fi in _enumType.GetFields())
        {
            DescriptionAttribute dna =
              (DescriptionAttribute)Attribute.GetCustomAttribute(
                fi, typeof(DescriptionAttribute));

            if ((dna != null) && ((string)value == dna.Description))
                return Enum.Parse(_enumType, fi.Name);
        }

        return Enum.Parse(_enumType, (string)value);
    }


}

 

 

Then use attribute Editor

 

[DisplayName("Country")]
[Description("Country")]
[TypeConverter(typeof(EnumTypeConverter))]
[Editor(typeof(CountryEditor), typeof(UITypeEditor))]
public Country Country
{
    get
    {
        return _Country;
    }
    set
    {
        _Country = value;
    }
}

 

 Now we can see the combo box as editor for our Enum type

 

Source ( russian )