Solved: Collection explicit conversion operator recommendation [modified] - C# Discussion Boards

the transparency goes when the panel is invalidated

27-Aug-10 2:10

NP[^]

Luc Pattyn [Forum Guidelines] [Why QA sucks] [My Articles] Nil Volentibus Arduum

Please use <PRE> tags for code snippets, they preserve indentation, and improve readability.

prasadbuddhika26-Aug-10 21:27

Re: the transparency goes when the panel is invalidated

26-Aug-10 21:27

i tried to create a transparent panel it worked using the

protected override CreateParams CreateParams<br />
        {<br />
            get<br />
            {<br />
                CreateParams cp = base.CreateParams;<br />
                cp.ExStyle |= 0x20;<br />
                return cp;<br />
            }<br />
        }

but now i'm trying move a rectangle in this panel,when doing this the transparency goes and the panel goes to it normal back color. any one having an idea how to solve this

i'm using this panel to because under this panel there is another panel that contains a screen shot,so when i'm moving the rectangle in the transparent panel, use sees it as in the 2nd panel.

thanx in advance.

OriginalGriff26-Aug-10 22:07

OriginalGriff

26-Aug-10 22:07

Instead of that, use a single panel, and draw the background image yourself in the Paint event. Then draw your rectangle on top of that.
Why complicate things with two panels?

Real men don't use instructions. They are only the manufacturers opinion on how to put the thing together.

Re: the transparency goes when the panel is invalidated

prasadbuddhika26-Aug-10 22:22

Re: the transparency goes when the panel is invalidated

26-Aug-10 22:22

thanx for your suggestion, but i can't use that panel because two panels are used by two different panels.

any more suggestions..!
thank you.

OriginalGriff26-Aug-10 22:23

OriginalGriff

26-Aug-10 22:23

prasadbuddhika wrote:
hat panel because two panels are used by two different panels

Any chance of that in English?

Real men don't use instructions. They are only the manufacturers opinion on how to put the thing together.

Re: the transparency goes when the panel is invalidated

prasadbuddhika26-Aug-10 22:39

Re: the transparency goes when the panel is invalidated

26-Aug-10 22:39

oh... sorry ..! i meant two panels are used by two threads..!

prasadbuddhika27-Aug-10 1:47

Solved: Collection explicit conversion operator recommendation [modified]

27-Aug-10 1:47

thanx OriginalGriff for your support

i got what i was expecting at this link http://www.weask.us/entry/clearing-graphics-transparent-panel[^]

DaveyM6926-Aug-10 11:57

Re: Collection explicit conversion operator recommendation

26-Aug-10 11:57

I have a custom collection which wraps a List<T>. I want to provide a conversion operator for the consumers convenience to List<T> but would you recommend:

1. Just returning the innerList

public static explicit operator List<T>(MyList<T> myList)
{
    return myList.innerList
}

2. Cloning by creating a new List<T> from the innerList

public static explicit operator List<T>(MyList<T> myList)
{
    return new List<T>(myList);
}

?
Obviously the first is way faster, but then any changes after an explicit cast would also be reflected in the collection :undecided:

Dave

If this helped, please vote & accept answer!

Binging is like googling, it just feels dirtier.
Please take your VB.NET out of our nice case sensitive forum.(Pete O'Hanlon)

BTW, in software, hope and pray is not a viable strategy. (Luc Pattyn)

modified on Thursday, August 26, 2010 7:03 PM

AspDotNetDev26-Aug-10 12:07

AspDotNetDev

26-Aug-10 12:07

You can just return a readonly version of the list, which is just as fast as returning the list unaltered (with the added benefit that the caller cannot modify the contents of the underlying list):

public static explicit operator System.Collections.ObjectModel.ReadOnlyCollection<int>(MyList<T> myList)
{
    return myList.innerList.AsReadOnly();
}

[Forum Guidelines]

Re: Collection explicit conversion operator recommendation

DaveyM6926-Aug-10 12:22

Re: Collection explicit conversion operator recommendation

26-Aug-10 12:22

Thanks, but I'm already implementing that in a method AsReadOnly() to provide consistant operation with the standard List<T> plus that would be an explicit cast to ReadOnlyCollection<T> and not List<T>.

I'm not concerned about keeping it read only, but more concerned about what a consumer of my collection would expect the behaviour to be. Maybe I just shouldn't provide the operator so there can't be any confusion?

Dave

If this helped, please vote & accept answer!

Binging is like googling, it just feels dirtier.
Please take your VB.NET out of our nice case sensitive forum.(Pete O'Hanlon)

BTW, in software, hope and pray is not a viable strategy. (Luc Pattyn)

AspDotNetDev26-Aug-10 12:46

AspDotNetDev

26-Aug-10 12:46

Yeah, if you're adding the operator just because you can, then I'd say there's probably not much value in doing so. If you want to provide some shorthand method so the user can get a list, you might want to provide a method, "CopyToList" or "GetList". If you are not worried about the list being readonly (i.e., the user can modify the list and it won't cause problems), then you could provide a public readonly property that returns the underlying list (perhaps call that property "InnerList").

If you do decide to go with an implicit conversion operator, I'd say it would be really unexpected for an operation as massive as a list copy to occur for a simple assignment to another reference type.

[Forum Guidelines]

Re: Collection explicit conversion operator recommendation

DaveyM6926-Aug-10 13:06

Re: Collection explicit conversion operator recommendation

26-Aug-10 13:06

aspdotnetdev wrote:
"CopyToList" or "GetList"

I might go with that - thanks Thumbs Up | :thumbsup:

Dave

If this helped, please vote & accept answer!

Binging is like googling, it just feels dirtier.
Please take your VB.NET out of our nice case sensitive forum.(Pete O'Hanlon)

BTW, in software, hope and pray is not a viable strategy. (Luc Pattyn)

Pete O'Hanlon26-Aug-10 12:43

Pete O'Hanlon

26-Aug-10 12:43

If I got a copy of the collection, I'd expect it to be consistent. I wouldn't expect it to change on me unexpectedly as a result of something manipulating the original list, so I'd clone the original list.

I have CDO, it's OCD with the letters in the right order; just as they ruddy well should be

My blog | My articles | MoXAML PowerToys | Onyx

Re: Collection explicit conversion operator recommendation

DaveyM6926-Aug-10 13:05

Re: Collection explicit conversion operator recommendation

26-Aug-10 13:05

I was leaning that way too - thanks Pete Thumbs Up | :thumbsup:

Dave

If this helped, please vote & accept answer!

Binging is like googling, it just feels dirtier.
Please take your VB.NET out of our nice case sensitive forum.(Pete O'Hanlon)

BTW, in software, hope and pray is not a viable strategy. (Luc Pattyn)

Luc Pattyn26-Aug-10 12:45

Re: Collection explicit conversion operator recommendation

26-Aug-10 12:45

Hi Dave,

I assume you had good reasons when you decided not to derive from List<T>.

I would not offer access to internal data, just like List<T> does not provide direct access to its internal array.

What I would consider, is adding a method ToList() which creates a List, probably by just cloning the internal List, and similar to List<T>.ToArray().

Cloning a List isn't really expensive, it basically is an Array.Copy(); it also offers the advantage of independent enumeration, i.e. no foreach-cannot-modify-this problem.

Smile | :)

Luc Pattyn [Forum Guidelines] [Why QA sucks] [My Articles] Nil Volentibus Arduum

Please use <PRE> tags for code snippets, they preserve indentation, and improve readability.

DaveyM6926-Aug-10 13:05

Re: Collection explicit conversion operator recommendation

26-Aug-10 13:05

Luc Pattyn wrote:
I assume you had good reasons when you decided not to derive from List<t>.

Yeah, not overwhelmingly great but good enough.

Good points - thanks as always Big Grin | :-D

Dave

If this helped, please vote & accept answer!

Binging is like googling, it just feels dirtier.
Please take your VB.NET out of our nice case sensitive forum.(Pete O'Hanlon)

BTW, in software, hope and pray is not a viable strategy. (Luc Pattyn)

Luc Pattyn26-Aug-10 13:10

Solved: Collection explicit conversion operator recommendation

26-Aug-10 13:10

You're welcome, as always.

Poke tongue | ;-P

Luc Pattyn [Forum Guidelines] [Why QA sucks] [My Articles] Nil Volentibus Arduum

Please use <PRE> tags for code snippets, they preserve indentation, and improve readability.

DaveyM6926-Aug-10 13:03

SOLVED: Hide subitem in standard listview [modified]

26-Aug-10 13:03

Thanks guys, just what I was looking for Thumbs Up | :thumbsup:

Dave

If this helped, please vote & accept answer!

Binging is like googling, it just feels dirtier.
Please take your VB.NET out of our nice case sensitive forum.(Pete O'Hanlon)

BTW, in software, hope and pray is not a viable strategy. (Luc Pattyn)

Marcel Vreuls (www.agentbase.nl)26-Aug-10 11:48

Marcel Vreuls (www.agentbase.nl)

26-Aug-10 11:48

Hi All,

I am using the standard Listview of Microsoft. Now i want the first column to be hidden. This column contains my key from which i access details. It is a technical id which the users do not care about and do not want to see. I can hide de column but not the subitem of the listview for it. I googled until my fingers burned, but cannot find a suitable solution. Any ideas??

Below is a part of the code from which i use.
With initialisation i run the ListViewAddColumns void. Then in code i loop trough my object and add each record to the listview. This all works fine!! but not i want to hide ListLines[0]. How can/should i do that.

if (objAll != null)
                        {
                            this.progressBar1.Maximum = objAll.Count;

                            foreach (statblCompany tblCompany in objAll)
                            {
                               progressBar1.Increment(1);

                                {
                                    string[] ListLines = new string[10];
                                    ListLines[0] = tblCompany.RE_ID.ToString();
                                    ListLines[1] = tblCompany.RE_NUMBER.ToString();
                                    ListLines[2] = tblCompany.RE_NAME;
                                    ListLines[3] = tblCompany.RE_PHONE;
                                    ListLines[4] = tblCompany.RE_VISITCITY;
                                    ListLines[5] = tblCompany.RE_EMAIL;
                                    ListLines[6] = xxGetIDDescription(tblCompany.RE_TYPE1);
                                    ListViewAddItem(ListLines, 200);
                                }
                            }
                            listView1.Columns[0].Width = 0;
                        }

private void ListViewAddColumns(String ColumnHeaders, int ColumnWidth)
       {
           ColumnHeader glColumn = new ColumnHeader();
           glColumn.Width = ColumnWidth;
           glColumn.Text = ColumnHeaders;
           glColumn.Width = ColumnWidth;
           listView1.Columns.Add(glColumn);
           //listView1.Columns[0].Width = 0;

       }

private void ListViewAddItem(string[] ListLines, double ColumnWidth)
        {
            try
            {
                ListViewItem olItem = new ListViewItem();

                ListViewItem.ListViewSubItem olSubItem0 = new ListViewItem.ListViewSubItem(olItem, ListLines[0]);
                ListViewItem.ListViewSubItem olSubItem1 = new ListViewItem.ListViewSubItem(olItem, ListLines[1]);
                ListViewItem.ListViewSubItem olSubItem2 = new ListViewItem.ListViewSubItem(olItem, ListLines[2]);
                ListViewItem.ListViewSubItem olSubItem3 = new ListViewItem.ListViewSubItem(olItem, ListLines[3]);
                ListViewItem.ListViewSubItem olSubItem4 = new ListViewItem.ListViewSubItem(olItem, ListLines[4]);
                ListViewItem.ListViewSubItem olSubItem5 = new ListViewItem.ListViewSubItem(olItem, ListLines[5]);
                ListViewItem.ListViewSubItem olSubItem6 = new ListViewItem.ListViewSubItem(olItem, ListLines[6]);
                ListViewItem.ListViewSubItem olSubItem7 = new ListViewItem.ListViewSubItem(olItem, ListLines[7]);
                ListViewItem.ListViewSubItem olSubItem8 = new ListViewItem.ListViewSubItem(olItem, ListLines[8]);
                ListViewItem.ListViewSubItem olSubItem9 = new ListViewItem.ListViewSubItem(olItem, ListLines[9]);

                
                olItem.SubItems.AddRange(new ListViewItem.ListViewSubItem[] {olSubItem0, olSubItem1, olSubItem2, olSubItem3, olSubItem4, olSubItem5, olSubItem6, olSubItem7, olSubItem8, olSubItem9});


                listView1.Items.Add(olItem);
                olItem = null;
                olSubItem0 = null;
                olSubItem1 = null;
                olSubItem2 = null;
                olSubItem3 = null;
                olSubItem4 = null;
                olSubItem5 = null;
                olSubItem6 = null;
                olSubItem7 = null;
                olSubItem8 = null;
                olSubItem9 = null;

                
            }
            catch (Exception ex)
            {
                ExceptionManager.Publish(ex);
            }
        }

Kind regards,

Marcel Vreuls

MarcelVreuls.com

<<A good idea can change your life>>

modified on Friday, August 27, 2010 6:19 AM

Message Closed

26-Aug-10 20:37

stancrm

26-Aug-10 20:37

Message Closed

modified 23-Nov-14 6:00am.

Re: Hide subitem in standard listview

Marcel Vreuls (www.agentbase.nl)27-Aug-10 0:19

Marcel Vreuls (www.agentbase.nl)

27-Aug-10 0:19

Hi,

That is exactly the solution i tried and worked. Thanks!!

Kind regards,

Marcel Vreuls

MarcelVreuls.com

<<A good idea can change your life>>

How to get url from browser to C# application

Saint_pl26-Aug-10 11:14

Saint_pl

26-Aug-10 11:14

Hi friends Smile | :)

I'm looking for way of getting url from browser like Chrome or Opera etc.
To get this from IE I use [DllImport(user32.dll)] and methods FindWindow, FindWindowEx and SendMessage.
In case of Firefox very helpful is NDde.dll and DdeClient class.

But I don't know how to get this from other browsers.
I thought about checking cache files, but it doesn't work e.g. in portable version. It must by other way...a library or sth...

Any ideas? Smile | :)

Re: How to get url from browser to C# application

Luc Pattyn26-Aug-10 13:41