Re: Passing any object type to a function - C# Discussion Boards

sameercodes28-Feb-10 20:12

28-Feb-10 20:12

Hi there,
I have a function

List<BaseEntity> ConvertList(List<BaseEntity> listBaseEntity)
{
//My code
}

Now I am calling the function as follows:

List<ChildEntity> listChild = new List<ChildEntity>();

listChild = ConvertList(listChild);

Here ChildEntity has base class as BaseEntity. On compiling I am getting error as :

Cannot convert type List<ChildEntity> to List<BaseEntity> via a reference conversion, boxing conversion, unboxing conversion, wrapping conversion, or null type conversion

Then I tried defining the function as

List<object> ConvertList(List<object> listObject)
{
//My Code
}

Again I am calling the function as follows:

List<ChildEntity> listChild = new List<ChildEntity>();

listChild = ConvertList(listChild);

Then I got the compile time error as

The best overloaded method match for ConvertList(List<object>)' has some invalid arguments

How do I resolve this issue? The list that I am passing to the ConvertList function could be of any type.
Thanks and Regards
-
Sameer

Re: Passing any object type to a function

KarstenK28-Feb-10 21:31

KarstenK

28-Feb-10 21:31

is the object/list type of your function correct?

listChild = ConvertList(ref listChild);

Press F1 for help or google it.
Greetings from Germany

Re: Passing any object type to a function

sameercodes28-Feb-10 22:10

sameercodes

28-Feb-10 22:10

Hi Karsten,
I did the exact way as u'd said but got the following error

The best overloaded method match for ConvertList(List<BaseEntity>) has some invalid arguments.

I'll reconstruct the scenario:

My function definition is as follows:

List<BaseEntity> ConvertList(List<BaseEntity>)
{
 //My code
}

And I am passing a child object which is inherited from base entity:

List<ChildEntity> listChildEntity = new List<ChildEntity>();

listChildEntity = ConvertList(ref listChildEntity);

Thanks
-
Sameer

Re: Passing any object type to a function

TheDudeJuan28-Feb-10 22:46

TheDudeJuan

28-Feb-10 22:46

The parameter in the ConvertList function accepts List<baseentity> but when you call the function you parse a ref of listChildEntity...

Dollartegn 8D

Re: Passing any object type to a function

sameercodes1-Mar-10 18:12

sameercodes

1-Mar-10 18:12

Hi Estys,
Thanks for the reply.

Actually the ChildEntity is just one example. The BaseEntity is a base class for many child entities, say ChildEntity1, ChildEntity2, ChildEntity3, etc.

Thus, the list could be of any of these types and certain convert actions need to be taken on the same.

Your solution seems to be great but if you take a look at the replies before, I have tried this and somehow this dint work.

I'll reconstruct the scenario again, in detail.

My ConvertList function belongs to a static class, say ListClassStatic

Thus I am calling the function as:

listChildList = ListClassStatic.ConvertList(ref listChildList);

Thanks and Regards
-
Sameer

Re: Passing any object type to a function

Estys1-Mar-10 2:27

Estys

1-Mar-10 2:27

listChild = ConvertList(listChild.ConvertAll<BaseEntity>(delegate (ChildEntity a) { return a as BaseEntity}))
                .ConvertAll<ChildEntity>(delegate (BaseEntity a) { return a as ChildEntity});

Each item in List<T> must be cast to the appropriate type and back.
Do you really need to pass a list? It looks horrible Dead | X|

Re: Passing any object type to a function

sameercodes1-Mar-10 18:05

sameercodes

1-Mar-10 18:05

Hi Estys,
Thanks for the reply. Yeah, I need to pass a list. Can't help it! Sigh | :sigh:

Actually the ChildEntity is just one example. The BaseEntity is a base class for May child entities, say, ChildEntity1, ChildEntity2, ChildEntity3, etc.

Thus, the list could be of any of these types and certain convert actions need to be taken on the same.

Your solution seems to be great, but aint it a bit complicated. Is there a simpler one?

Thanks and Regards
-
Sameer

Re: Passing any object type to a function

Estys1-Mar-10 21:07

Estys

1-Mar-10 21:07

This works :

static void Conv (BaseEntity baseEntity)
        {
            baseEntity.id = "b"; //your code here
        }

Invoke like this :

listChild.ForEach(Conv);

It doesn't use a list. Your problem with List<T> is that it won't cast to another type.

How to handle the localization stuff in Crystal reports XI.

idreesbadshah28-Feb-10 19:23

idreesbadshah

28-Feb-10 19:23

Hi,
We are using Crystal reports 11 (developer version) in our product. I would like to know, how can we handle the localization stuff in crystal reports other than using the third party tools (like "Crystal Translator"
Our application is developed in C# . Here for localization stuff in C#is very simple and we can place all strings in .resx, then the translation is required for only the .rc file according to the language.

Is there any similar functionality/feature is there crystal reports 11 to support for the localization stuff ?.

If you guys through some light on this, it will be very helpful to me.

Thanks

C# and XML [modified]

picasso228-Feb-10 18:16

picasso2

28-Feb-10 18:16

I have a XML file (foo.xml)that contains about 100 tags. One of the tags looks like this:

"<"CONNECTION HOST ="XYZ"/>

NOTE-no quotation marks before or after the starting less-than sign

Any body has an example on how to extract the XYZ data using C#?

your help is greatly appreciated

modified on Monday, March 1, 2010 12:22 AM

Re: C# and XML

Mycroft Holmes28-Feb-10 18:48

Mycroft Holmes

28-Feb-10 18:48

That is NOT a well formed XML file, you cannot expect XML to work on crap data, you will need to parse this manually, just like any other text file.

You could read it in and to a replace on "<", then use the xml parser!

Never underestimate the power of human stupidity
RAH

Re: C# and XML

picasso21-Mar-10 16:40

picasso2

1-Mar-10 16:40

It is well-formatted, it just does not display correctly if I type it the correct way and hence the NOTE-no quotation marks before or after the starting less-than sign
basically it is
OPEN bracket-CONNECTION HOST ="XYZ"/ - close bracket

Re: C# and XML

Saksida Bojan28-Feb-10 19:03

Saksida Bojan

28-Feb-10 19:03

We can't see your tag: Try checking this before pasting your XML: Encode "<" (and other HTML) characters when pasting

edit: Damm, my browser cache.

XmlDocument doc = new XmlDocument();
doc.LoadXml("<CONNECTION HOST =\"XYZ\"/>");
XmlElement xml = doc.DocumentElement;
MessageBox.Show("Atribute name: " + xml.Attributes[0].Name + "\r\n Atribute Value: " + xml.Attributes[0].Value);

Save a variable

suprsnipes28-Feb-10 15:15

suprsnipes

28-Feb-10 15:15

Hi,

I'm a newbie and need some help.

How do I go about saving a variable using c# code.

Re: Save a variable

DaveyM6928-Feb-10 15:28

DaveyM69

28-Feb-10 15:28

It depends on the type of the variable and what you mean by 'saving'... to a file, a database, in memory, sharing with another class etc...

Dave

Tip: Passing values between objects using events (C#)

BTW, in software, hope and pray is not a viable strategy. (Luc Pattyn)
Why are you using VB6? Do you hate yourself? (Christian Graus)

Re: Save a variable

suprsnipes28-Feb-10 16:07

suprsnipes

28-Feb-10 16:07

Thanks alot for the reply.

I need to save the variable temporarily for use later.

Thanks in advance for any help you can provide...

Re: Save a variable

PIEBALDconsult28-Feb-10 16:10

PIEBALDconsult

28-Feb-10 16:10

How much later?

Re: Save a variable

suprsnipes28-Feb-10 16:14

suprsnipes

28-Feb-10 16:14

I would say hours at the most

Re: Save a variable

Mycroft Holmes28-Feb-10 16:58

Mycroft Holmes

28-Feb-10 16:58

Look into variable SCOPE, assuming you are not talking about saving the value past the end of the current session (stopping the application) a variable is available until it runs out of SCOPE. Do NOT fall into the VB trap of making all your variables global or static.

Never underestimate the power of human stupidity
RAH

C# Times

Illegal Operation28-Feb-10 12:19

Illegal Operation

28-Feb-10 12:19

Hi!

I have a problem. I have created a time sheet system that enables a person to enter a start time and an end time. It then calculates the total hours worked.

The problem I have is this:

When a person has been on lunch from say 11:00 to 11:30 and then wants to enter a time worked say 11:15 then an exception should be thrown stating that times cannot overlap. How will I go about checking for this?

Thanks in advance!!

Illegal Operation

Re: C# Times

Luc Pattyn28-Feb-10 12:33

Luc Pattyn

28-Feb-10 12:33

two intervals [b1,e1] and [b2,e2] overlap when any of the following is true:

b1<=b2<=e1
b1<=e2<=e1
b2<=b1<=e2
b2<=e1<=e2

So start comparing begin and end DateTimes.

Smile | :)

Luc Pattyn [Forum Guidelines] [Why QA sucks] [My Articles]

I only read code that is properly formatted, adding PRE tags is the easiest way to obtain that.
All Toronto weekends should be extremely wet until we get it automated in regular forums, not just QA.

modified on Sunday, February 28, 2010 8:15 PM

Re: C# Times

David Skelly28-Feb-10 22:27

David Skelly

28-Feb-10 22:27

If you google for c# DateRange you will find a number of classes that people have written to address this sort of problem, i.e. dealing with fixed periods of time and testing for intersection with other periods, and so on. One example is here:

http://noticeablydifferent.com/CodeSamples/DateRange.aspx[^]

This example is OK, except I would make it immutable since in its present form it's not thread-safe.

move a file from one directory to another

Yustme28-Feb-10 12:15

Yustme

28-Feb-10 12:15

Hi,

I'm trying to move a file from 1 directory to another.

But no matter what I try, I keep getting this error at runtime:

Cannot create a file when that file already exists.

string[] filePaths = Directory.GetFiles(dir1, "*.txt");

Directory.Move(filePaths[i], checkedFiles);

All the files in filePaths are in bin\debug\FilesToCheck folder

And checkedFiles folder is in bin\debug\checkedFiles

What am I doing wrong?

Re: move a file from one directory to another

Luc Pattyn28-Feb-10 12:34

Luc Pattyn

28-Feb-10 12:34

Make sure checkedFiles ends on a backslash, making it a folder, not a file.

Smile | :)

Luc Pattyn [Forum Guidelines] [Why QA sucks] [My Articles]

Re: move a file from one directory to another

Yustme28-Feb-10 12:57

Yustme

28-Feb-10 12:57

It has an ending backslash. The file is made with Path.Combine()

And in there i added the ending slash.

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.