public override object EditValue(ITypeDescriptorContext context, IServiceProvider provider, object value)
{
// if value is not an enum than we can not edit it
if (!(value is Enum))
{
throw new Exception("Value doesn't support");
}
// try to figure out that is this a Flags enum or not ?
Type enumType = value.GetType();
object[] attributes = enumType.GetCustomAttributes(typeof(FlagsAttribute), true);
if (attributes.Length == 0)
{
throw new Exception("Editing enum hasn't got Flags attribute");
}
// check the underlying type
Type type = Enum.GetUnderlyingType(value.GetType());
if (type != typeof(byte) && type != typeof(sbyte) &&
type != typeof(short) && type != typeof(ushort) &&
type != typeof(int) && type != typeof(uint))
{
return(value);
}
if (provider != null)
{
// use windows forms editor service to show drop down
IWindowsFormsEditorService edSvc = provider.GetService(typeof(IWindowsFormsEditorService))
as IWindowsFormsEditorService;
if (edSvc == null)
{
return(value);
}
if (editor == null)
{
editor = new FlagsEditorControl(this);
}
// prepare list
editor.Begin(edSvc, value);
// show drop down now
edSvc.DropDownControl(editor);
// now we take the result
value = editor.Value;
// reset
editor.End();
}
return(Convert.ChangeType(value, type));
}
public override object EditValue(ITypeDescriptorContext context, IServiceProvider provider, object value)
{
// Validate parameter(s).
if (provider == null)
{
return(value);
}
if (value == null)
{
return(value);
}
// Validate value is a enum type with Flags attribute.
if (!value.GetType().IsEnum)
{
return(value);
}
object[] attributes = value.GetType().GetCustomAttributes(typeof(FlagsAttribute), false);
if ((attributes == null) ||
(attributes.Length == 0))
{
return(value);
}
// Show panel.
IWindowsFormsEditorService service = (IWindowsFormsEditorService)provider.GetService(typeof(IWindowsFormsEditorService));
if (service != null)
{
FlagsEditorControl control = new FlagsEditorControl(value);
service.DropDownControl(control);
// Create new enum value.
Type type = value.GetType();
object newValue = Activator.CreateInstance(type);
FieldInfo field = type.GetFields(BindingFlags.Public | BindingFlags.Instance)[0];
field.SetValue(newValue, control.EditValue);
control.Dispose();
return(newValue);
}
else
{
return(value);
}
}
public override object EditValue(ITypeDescriptorContext context, IServiceProvider provider, object value)
{
// Validate parameter(s).
if (provider == null)
{
return value;
}
if (value == null)
{
return value;
}
// Validate value is a enum type with Flags attribute.
if (!value.GetType().IsEnum)
{
return value;
}
object[] attributes = value.GetType().GetCustomAttributes(typeof(FlagsAttribute), false);
if ((attributes == null)
|| (attributes.Length == 0))
{
return value;
}
// Show panel.
IWindowsFormsEditorService service = (IWindowsFormsEditorService)provider.GetService(typeof(IWindowsFormsEditorService));
if (service != null)
{
FlagsEditorControl control = new FlagsEditorControl(value);
service.DropDownControl(control);
// Create new enum value.
Type type = value.GetType();
object newValue = Activator.CreateInstance(type);
FieldInfo field = type.GetFields(BindingFlags.Public | BindingFlags.Instance)[0];
field.SetValue(newValue, control.EditValue);
control.Dispose();
return newValue;
}
else
{
return value;
}
}
