Hello,

I have a class as follows:

public class Theme {

public Subject Subject { get; set; }
public List<Level> Levels { get; set; }
public string Note { get; set; }

public Theme() {
this.Levels.Add(new Level { Type = LevelType.Basico,
Description = "Test" });
}

Level is a class with two properties:
- Type (of type LevelType which is an Enum)
- Description which is a string

I am getting an error:
Object reference not set to an instance of an object.

What am I doing wrong?

Probably this is something simple but I have been around this and I
can't figure out what I am doing wrong.

Thanks,
Miguel

Hi Miguel,

It appears that this.Levels (actually, the field that is used in the Levels
property) is not initialized. Instantiate it as new List<Level>() in either
your constructor before the this.Levels.Add() call or inline beside the
declaration.
--
Stanimir Stoyanov
http://stoyanoff.info

"shapper" <(E-Mail Removed)> wrote in message
news:de7831c8-9af3-4869-90a2-(E-Mail Removed)...
> Hello,
>
> I have a class as follows:
>
> public class Theme {
>
> public Subject Subject { get; set; }
> public List<Level> Levels { get; set; }
> public string Note { get; set; }
>
> public Theme() {
> this.Levels.Add(new Level { Type = LevelType.Basico,
> Description = "Test" });
> }
>
> Level is a class with two properties:
> - Type (of type LevelType which is an Enum)
> - Description which is a string
>
> I am getting an error:
> Object reference not set to an instance of an object.
>
> What am I doing wrong?
>
> Probably this is something simple but I have been around this and I
> can't figure out what I am doing wrong.
>
> Thanks,
> Miguel
>

shapper wrote:

> Hello,
>
> I have a class as follows:
>
> public class Theme {
>
> public Subject Subject { get; set; }
> public List<Level> Levels { get; set; }
> public string Note { get; set; }
>
> public Theme() {
> this.Levels.Add(new Level { Type = LevelType.Basico,
> Description = "Test" });
> }
>
> Level is a class with two properties:
> - Type (of type LevelType which is an Enum)
> - Description which is a string
>
> I am getting an error:
> Object reference not set to an instance of an object.
>
> What am I doing wrong?

You never instantiate the list, I guess. Somewhere, you should have
something like:

Levels = new List<Level>();

You could even put such code in the getter, i.e. if Levels is
unassigned, then instantiate it.
--
Rudy Velthuis http://rvelthuis.de

"Emulate your heros, but don't carry it too far. Especially
if they are dead."

You cannot put it inline in an automatic property, can you?

"Stanimir Stoyanov" wrote:

> Hi Miguel,
>
> It appears that this.Levels (actually, the field that is used in the Levels
> property) is not initialized. Instantiate it as new List<Level>() in either
> your constructor before the this.Levels.Add() call or inline beside the
> declaration.
> --
> Stanimir Stoyanov
> http://stoyanoff.info
>
> "shapper" <(E-Mail Removed)> wrote in message
> news:de7831c8-9af3-4869-90a2-(E-Mail Removed)...
> > Hello,
> >
> > I have a class as follows:
> >
> > public class Theme {
> >
> > public Subject Subject { get; set; }
> > public List<Level> Levels { get; set; }
> > public string Note { get; set; }
> >
> > public Theme() {
> > this.Levels.Add(new Level { Type = LevelType.Basico,
> > Description = "Test" });
> > }
> >
> > Level is a class with two properties:
> > - Type (of type LevelType which is an Enum)
> > - Description which is a string
> >
> > I am getting an error:
> > Object reference not set to an instance of an object.
> >
> > What am I doing wrong?
> >
> > Probably this is something simple but I have been around this and I
> > can't figure out what I am doing wrong.
> >
> > Thanks,
> > Miguel
> >
>
>

On Oct 30, 2:58*pm, shapper <mdmo...@gmail.com> wrote:
> Hello,
>
> I have a class as follows:
>
> * public class Theme {
>
> * * public Subject Subject { get; set; }
> * * public List<Level> Levels { get; set; }
> * * public string Note { get; set; }
>
> * * public Theme() {
> * * * * this.Levels.Add(new Level { Type = LevelType.Basico,
> Description = "Test" });
> * * }
>
> Level is a class with two properties:
> - Type (of type LevelType which is an Enum)
> - Description which is a string
>
> I am getting an error:
> Object reference not set to an instance of an object.
>
> What am I doing wrong?
>
> Probably this is something simple but I have been around this and I
> can't figure out what I am doing wrong.
>
> Thanks,
> Miguel

You are missing a () set
this.Levels.Add(new()

Tip:
Download & install SP1 , it has a very improved intellisence

No, the compiler takes care of creating a private field for that purpose in
that case, so it is not accessible to us for modifications. That was
probably a mistake on my part for not interpreting the code Miguel posted
correctly. I figured he might have omitted unnecessary getter/setter code
for his post.

--
Stanimir Stoyanov
http://stoyanoff.info

"Family Tree Mike" <(E-Mail Removed)> wrote in
message news:05906494-A10A-478A-9BAE-(E-Mail Removed)...
> You cannot put it inline in an automatic property, can you?
>
> "Stanimir Stoyanov" wrote:
>
>> Hi Miguel,
>>
>> It appears that this.Levels (actually, the field that is used in the
>> Levels
>> property) is not initialized. Instantiate it as new List<Level>() in
>> either
>> your constructor before the this.Levels.Add() call or inline beside the
>> declaration.
>> --
>> Stanimir Stoyanov
>> http://stoyanoff.info
>>
>> "shapper" <(E-Mail Removed)> wrote in message
>> news:de7831c8-9af3-4869-90a2-(E-Mail Removed)...
>> > Hello,
>> >
>> > I have a class as follows:
>> >
>> > public class Theme {
>> >
>> > public Subject Subject { get; set; }
>> > public List<Level> Levels { get; set; }
>> > public string Note { get; set; }
>> >
>> > public Theme() {
>> > this.Levels.Add(new Level { Type = LevelType.Basico,
>> > Description = "Test" });
>> > }
>> >
>> > Level is a class with two properties:
>> > - Type (of type LevelType which is an Enum)
>> > - Description which is a string
>> >
>> > I am getting an error:
>> > Object reference not set to an instance of an object.
>> >
>> > What am I doing wrong?
>> >
>> > Probably this is something simple but I have been around this and I
>> > can't figure out what I am doing wrong.
>> >
>> > Thanks,
>> > Miguel
>> >
>>
>>

On Oct 30, 7:28*pm, "Stanimir Stoyanov" <stoya...@REMOVETHIS.live.com>
wrote:
> No, the compiler takes care of creating a private field for that purpose in
> that case, so it is not accessible to us for modifications. That was
> probably a mistake on my part for not interpreting the code Miguel posted
> correctly. I figured he might have omitted unnecessary getter/setter code
> for his post.
>
> --
> Stanimir Stoyanovhttp://stoyanoff.info
>
> "Family Tree Mike" <FamilyTreeM...@discussions.microsoft.com> wrote in
> messagenews:05906494-A10A-478A-9BAE-(E-Mail Removed)...
>
> > You cannot put it inline in an automatic property, can you?
>
> > "Stanimir Stoyanov" wrote:
>
> >> Hi Miguel,
>
> >> It appears that this.Levels (actually, the field that is used in the
> >> Levels
> >> property) is not initialized. Instantiate it as new List<Level>() in
> >> either
> >> your constructor before the this.Levels.Add() call or inline beside the
> >> declaration.
> >> --
> >> Stanimir Stoyanov
> >>http://stoyanoff.info
>
> >> "shapper" <mdmo...@gmail.com> wrote in message
> >>news:de7831c8-9af3-4869-90a2-(E-Mail Removed)....
> >> > Hello,
>
> >> > I have a class as follows:
>
> >> > *public class Theme {
>
> >> > * *public Subject Subject { get; set; }
> >> > * *public List<Level> Levels { get; set; }
> >> > * *public string Note { get; set; }
>
> >> > * *public Theme() {
> >> > * * * *this.Levels.Add(new Level { Type = LevelType.Basico,
> >> > Description = "Test" });
> >> > * *}
>
> >> > Level is a class with two properties:
> >> > - Type (of type LevelType which is an Enum)
> >> > - Description which is a string
>
> >> > I am getting an error:
> >> > Object reference not set to an instance of an object.
>
> >> > What am I doing wrong?
>
> >> > Probably this is something simple but I have been around this and I
> >> > can't figure out what I am doing wrong.
>
> >> > Thanks,
> >> > Miguel

Thanks!