Array conversion question

[Pavils Jurjans]

Hello,

I think this is classical problem, but I can't figure out how to do it in
most right way (I know ineffective way though

So, I have this method that does some database work and has to return an
array of custom type, let's say

public MyType[] MyMethod(params)
{
ArrayList output = new ArrayList();
}

Since the return array can be of different sizes, dependinf on parameters, I
use standard ArrayList within the body of MyMethod to gather the results.
Whenever a new element is added, something like this is executed:

MyType element = new MyType();
// Some element data populating code
output.Add(element);

Now, when I need to return the output, I need to do some kind of chemistry
so that it is returned as correct MyType[]. What is the most appropriate
way?

Thanks,

Pavils Jurjans

 

[Christiaan van Bergen]

Hi Pavils,

A bit crude, I must admit.......(this is probably your ineffective way)

MyType[] Result = new MyType[output.Count];
for(int x=0;x<output.Count;x++)
{
Result[x] = output[x] as MyType;
}

Cheers
Christiaan

 

[Scott Coonce]

Try the following (or something like it, untested code follows):


MyType[] buf = new MyType[somearraylist.Count];
somearraylist.CopyTo(buf);

I think does it.

Scott

Hi Pavils,

A bit crude, I must admit.......(this is probably your ineffective way)

MyType[] Result = new MyType[output.Count];
for(int x=0;x<output.Count;x++)
{
Result[x] = output[x] as MyType;
}

Cheers
Christiaan

Hello,

I think this is classical problem, but I can't figure out how to do it in
most right way (I know ineffective way though

So, I have this method that does some database work and has to return an
array of custom type, let's say

public MyType[] MyMethod(params)
{
ArrayList output = new ArrayList();
}

Since the return array can be of different sizes, dependinf on
parameters, I use standard ArrayList within the body of MyMethod to
gather the results. Whenever a new element is added, something like this
is executed:

MyType element = new MyType();
// Some element data populating code
output.Add(element);

Now, when I need to return the output, I need to do some kind of
chemistry so that it is returned as correct MyType[]. What is the most
appropriate way?

Thanks,

Pavils Jurjans

 

[Christiaan van Bergen]

That's it Scott,

Even better

Christiaan

Try the following (or something like it, untested code follows):


MyType[] buf = new MyType[somearraylist.Count];
somearraylist.CopyTo(buf);

I think does it.

Scott

Hi Pavils,

A bit crude, I must admit.......(this is probably your ineffective way)

MyType[] Result = new MyType[output.Count];
for(int x=0;x<output.Count;x++)
{
Result[x] = output[x] as MyType;
}

Cheers
Christiaan

Hello,

I think this is classical problem, but I can't figure out how to do it
in most right way (I know ineffective way though

So, I have this method that does some database work and has to return an
array of custom type, let's say

public MyType[] MyMethod(params)
{
ArrayList output = new ArrayList();
}

Since the return array can be of different sizes, dependinf on
parameters, I use standard ArrayList within the body of MyMethod to
gather the results. Whenever a new element is added, something like this
is executed:

MyType element = new MyType();
// Some element data populating code
output.Add(element);

Now, when I need to return the output, I need to do some kind of
chemistry so that it is returned as correct MyType[]. What is the most
appropriate way?

Thanks,

Pavils Jurjans

 

[Richard Blewett [DevelopMentor]]

That's it Scott,

Even better

Christiaan

Try the following (or something like it, untested code follows):


MyType[] buf = new MyType[somearraylist.Count];
somearraylist.CopyTo(buf);

I think does it.

Scott

Hi Pavils,

A bit crude, I must admit.......(this is probably your ineffective way)

MyType[] Result = new MyType[output.Count];
for(int x=0;x<output.Count;x++)
{
Result[x] = output[x] as MyType;
}

Cheers
Christiaan

"Pavils Jurjans" <[email protected]> schreef in bericht
Hello,

I think this is classical problem, but I can't figure out how to do it
in most right way (I know ineffective way though

So, I have this method that does some database work and has to return
an array of custom type, let's say

public MyType[] MyMethod(params)
{
ArrayList output = new ArrayList();
}

Since the return array can be of different sizes, dependinf on
parameters, I use standard ArrayList within the body of MyMethod to
gather the results. Whenever a new element is added, something like
this is executed:

MyType element = new MyType();
// Some element data populating code
output.Add(element);

Now, when I need to return the output, I need to do some kind of
chemistry so that it is returned as correct MyType[]. What is the most
appropriate way?

Thanks,

Pavils Jurjans

static int[] Foo()
{
ArrayList arr = new ArrayList();
...
return (int[])arr.ToArray(typeof(int));
}

Regards

Richard Blewett - DevelopMentor
http://www.dotnetconsult.co.uk/weblog
http://www.dotnetconsult.co.uk

 

[Ignacio Machin \( .NET/ C# MVP \)]

Hi,


In addition to the others proposals a possible solution would be (assuming
you are querying a DB with an SP and returning a DataReader):

create a output parameter, will contain the number of rows.
execute the reader
create the correct size array
populate the array

return the array


The only thing pending would be how to get the number of rows in the SP,
that depends of your DB and your query.


cheers,

 

[Pavils Jurjans]

static int[] Foo()
{
ArrayList arr = new ArrayList();
...
return (int[])arr.ToArray(typeof(int));
}

Richard Blewett - DevelopMentor

Thanks, this proved to be the shortest and best!

Rgds, Pavils