array list

  • Thread starter Thread starter Hrcko
  • Start date Start date
Hi Hrcko,

You need to add each item in turn to an array or an ArrayList

object[] o = new object[listBox1.Items.Count];
for(int i = 0; i < o.Length; i++)
o = listBox1.Items;

Or ...

ArrayList list = new ArrayList();
foreach(object o in listBox1.Items)
list.Add(o);
 
You need to add each item in turn to an array or an ArrayList

object[] o = new object[listBox1.Items.Count];
for(int i = 0; i < o.Length; i++)
o = listBox1.Items;

Or ...

ArrayList list = new ArrayList();
foreach(object o in listBox1.Items)
list.Add(o);
Click to expand...



If you don't want to write that much code, just create the ArrayList...

ArrayList a = new ArrayList( this.listBox1.Items );

Or if you wanted it as an array instead of an ArrayList...

Object[] a = new ArrayList( this.listBox1.Items ).ToArray();


// Bjorn A
 
I have a problem with this code because I have a Guid in my listBox.

I can't convert System.Guid to Guid[].

Hrcko
 
Ah, you are right. Had the impression that the overloaded constructor needed an object[], but all it needs is an ICollection.

Also, Hrcko, if you have a previously created ArrayList, you can use ArrayList.AddRange(ListBox.Items).

You need to add each item in turn to an array or an ArrayList

object[] o = new object[listBox1.Items.Count];
for(int i = 0; i < o.Length; i++)
o = listBox1.Items;

Or ...

ArrayList list = new ArrayList();
foreach(object o in listBox1.Items)
list.Add(o);
Click to expand...



If you don't want to write that much code, just create the ArrayList...

ArrayList a = new ArrayList( this.listBox1.Items );

Or if you wanted it as an array instead of an ArrayList...

Object[] a = new ArrayList( this.listBox1.Items ).ToArray();


// Bjorn A
Click to expand...
 
I have a problem with this code because I have a Guid in my listBox.

I can't convert System.Guid to Guid[].

Hrcko
 
...
I have a problem with this code because I
have a Guid in my listBox.

I can't convert System.Guid to Guid[].
Click to expand...

I think you possibly need to explain a little more what your problem is...

If you mean that you want a single Guid to appear in an array, well...

Lets say you have a System.Guid variable g...

System.Guid[] guidArray = {g};

...or were you referring to how to extract the elements of the listbox *as*
an array of Guid's?

Guid[] guidArray = (Guid[])
new ArrayList( this.listBox1.Items ).ToArray(typeof(Guid));


// Bjorn A
 
I need to put a list of Guids from listBox into Guid Array.

Hrcko

Bjorn Abelli said:
...
I have a problem with this code because I
have a Guid in my listBox.

I can't convert System.Guid to Guid[].
Click to expand...

I think you possibly need to explain a little more what your problem is...

If you mean that you want a single Guid to appear in an array, well...

Lets say you have a System.Guid variable g...

System.Guid[] guidArray = {g};

..or were you referring to how to extract the elements of the listbox *as*
an array of Guid's?

Guid[] guidArray = (Guid[])
new ArrayList( this.listBox1.Items ).ToArray(typeof(Guid));


// Bjorn A
Click to expand...
 
...
I need to put a list of Guids from listBox into Guid Array.
Click to expand...

So did you try the example I wrote?

Guid[] guidArray = (Guid[])
new ArrayList( this.listBox1.Items ).ToArray(typeof(Guid));


// Bjorn A
 
This all works fine.

Now, I would like to chek if that array list is empty.

Hrcko


Bjorn Abelli said:
...
I need to put a list of Guids from listBox into Guid Array.
Click to expand...

So did you try the example I wrote?

Guid[] guidArray = (Guid[])
new ArrayList( this.listBox1.Items ).ToArray(typeof(Guid));


// Bjorn A
Click to expand...
 
...
Now, I would like to chek if that array list is empty.
Click to expand...

You could either check the number of items *before* you get them from the
listbox...

if (this.listBox1.Items.Count == 0) ...

....or check the length of the array after you've created it

if (guidArray.Length == 0) ...

// Bjorn A
 
listBox1.Items.AddRange(guidArray);

Or, if your goal is to take the items from one ListBox (or other list control) and put them in another you can do

listBox2.Items.AddRange(listBox1.Items);
 
Correction :

I want to display items that ARE NOT in my array list...

I wrote some code but I don't know how to exclude those items
nUserID is an array list.
if (nUserID.Length != 0)

{


listUsers.DisplayMember = "UserName";

sSelectString = "UserID<>'" + nUserID.ToString() + "'";


DataRow[] Urows = db.dataSetAccounts.Users.Select(

sSelectString,"UserName",System.Data.DataViewRowState.CurrentRows);

foreach ( DataSetAccounts.UsersRow row in Urows )

{

DataSetAccounts.UsersRow users =

db.dataSetAccounts.Users.FindByUserID ( row.UserID );

if ( users != null )

{

listUsers.Items.Add( users );

}

}


}

Hrcko
 
...
I want to display items that ARE NOT in my array list...

I wrote some code but I don't know how to exclude those items
nUserID is an array list.
Click to expand...

....and your code isn't that much helpful to understand your problem...

(BTW, your use of the words "array list" when actually talking about just an
"array" is a bit confusing...)

What I can see is that

- you have an array "nUserID".
- you have a ListBox "listUsers"

But my guess is that you're not storing items of the same type in both?

....and now you want to poulate "listUsers" with something you read from a
database, except for those that exist in "nUserID"?

Well...

Your code doesn't show what is what or of what types, or what the types look
like, but if I guess that a DataSetAccounts.UsersRow has an attribute
"UserID", which can or cannot be found in the array...


if ( users != null && Array.IndexOf(nUserID, users.UserID) < 0 )
{
listUsers.Items.Add( users );
}


// Bjorn A
 
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