TypeConverter.GetStandardValues

[Karsten Schramm]

Hi,

what kind of object has this method to return?

Generally the MSDN says return a list of the original data types. If it
comes to an example the instruction says return a list of strings. But
then the code example (in most cases an array of ints) returns a list
of ints. Unfortunately ints are implicitly castable to string.

So let's take an more un-obvious example. Lets say I have a class
Hotzenplotz and I want to have a TypeConverter. Hotzenplotz is
convertible from and to int and string.

Does GetStandardValues return a list of Hotzenplotz or a list of
string?

IMHO a list of Hotzenplotz, if you need it converted to string (e.g.
for an UI) one has to call ConvertTo(hotzenplotzObject,
typeof(string)).

Am I right or wrong?

[Marc Gravell]

Well according to the below, it expects strings, but I've generally returned
typed items. When the PropertyGrid uses it, it calls ConvertTo [string]
anyway... it then calls ConvertFrom [string] afterwards to get back your
item. Presumably this is to support combo-style usage. A custom caller could
presumably just use the native objects themselves in a drop-down (not
combo), and rely on the .ToString().

http://msdn.microsoft.com/library/de...econverter.asp

<quote>
* Override the GetStandardValuesSupported method and return true.
* Override the GetStandardValues method and return a
StandardValuesCollection containing the standard values for the property
type. The standard values for a property type must be of type string.
* Override the CanConvertFrom method and return true for a sourceType
parameter value of type string.
* Override the ConvertFrom method and return the appropriate value for the
property based on the value parameter.
</quote>

Marc

[Karsten Schramm]

Hi,

Marc Gravell schrieb:

Well according to the below, it expects strings

http://msdn.microsoft.com/library/de...econverter.asp

that's my point: It says it expects strings, but the code sample
returns ints:
values = new ArrayList(new int[] { 1, 2, 3, 4, 5 });
StandardValuesCollection svc = new StandardValuesCollection(values);

[Karsten Schramm]

Hi,

Marc Gravell schrieb:

Well according to the below, it expects strings

http://msdn.microsoft.com/library/de...econverter.asp

that's my point: It says it expects strings, but the code sample
returns ints:
values = new ArrayList(new int[] { 1, 2, 3, 4, 5 });
StandardValuesCollection svc = new StandardValuesCollection(values);

Greetings,
Karsten

[Marc Gravell]

Looks like our instincts were right and the original docs were wrong; in
MSDN2:

http://msdn2.microsoft.com/en-us/library/ayybcxe5.aspx

<quote>
3. Override the GetStandardValues method and return a
StandardValuesCollection containing the standard values for the property
type. The standard values for a property must be of the same type as the
property itself.
</quote>

Sorted?

Marc

[Karsten Schramm]

Hi,

Marc Gravell schrieb:

Sorted?

No, I'm very untidy. ;-)

Thanks!

Karsten