|
|
Hey guys,
I need to add about 7000-14000 items to a listview.
But listing all the items is far too slow.
Do you have any idea how to make it faster?
thank you very much!
I use the following method:
private void trvLeft_AfterSelect(object sender, System.Windows.Forms.TreeViewEventArgs e)
{
DataRow[] rows = new DataRow [PnlSelect.pMCPTVARIABLEDESC .Rows.Count ];
System.Windows .Forms .ListView .ListViewItemCollection itlist= new System.Windows .Forms .ListView .ListViewItemCollection(lsvLeft);
try
{
lsvLeft.BeginUpdate ();
Cursor.Current =System.Windows .Forms .Cursors .WaitCursor;
//Clear old content:
lsvLeft.Clear ();//lsvLeft is my ListView
pTrvLeftTag=(TrvLeftTag)e.Node.Tag ;
rows=PnlSelect.pMCPTVARIABLEDESC .Select ("VARGROUPID='"+pTrvLeftTag.vargroup +"' AND CONNECTIONID='"+pTrvLeftTag.connection +"'");
foreach(DataRow row in rows)
{
itlist.Add(row["VARIABLENAME"].ToString ());
}
//add images
foreach( ListViewItem it in lsvLeft.Items )
{
it.ImageIndex =6;
}
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message );
}
finally
{
lsvLeft.EndUpdate ();
Cursor.Current =System.Windows .Forms .Cursors .Default;
}
}
|
|
|
|
|
Leia2011 wrote: I need to add about 7000-14000 items to a listview.
Well, that's not really a sensible UI. You probably need to show a filtered view. How is someone going to navigate these 10000 odd items ?
Christian Graus - Microsoft MVP - C++
Metal Musings - Rex and my new metal blog
"I am working on a project that will convert a FORTRAN code to corresponding C++ code.I am not aware of FORTRAN syntax" ( spotted in the C++/CLI forum )
|
|
|
|
|
7000-14000 items?? Why on earth would anyone want to go through that many items? I think you have a bit of a design flaw in your UI.
|
|
|
|
|
hi,
It is important to show all those items, it should not be a design flaw.
My Listview should contain all variables of a industrial plant.
the user should select about 10 variables from that listview and these 10 variables will be shown in an configurable protocol afterwards.
I reading my data out of an SQL-table which is filled by the Siemens visualization software WinCC.
The problem is that there are so many variables.
I have decided to use a listbox now. I doesn't look as good as a listview and has not that much option, but those 100000 items are there in a minute...
i do not have other ideas...
kind regards
|
|
|
|
|
Leia2011 wrote: it should not be a design flaw.
Actually, it IS a desgin flaw, on your part. Noone is going to go through a list of 14,000 items to pick 10 of them.
Redesgin you interface so the items are seperated into logical groups so the user can narrow down the list to just the items in a particular group.
If you put 14,000 items into a list view and expect someone to look through them all, I guarantee you the users will hunt you down and shove the installation CD where the sun don't shine.
|
|
|
|
|
.AddRange() ?
But, yeah, that's a lot of stuff. Some sort of filter would be good.
|
|
|
|
|
Hi,
I will not discuss if it is reasonable to display that much lines - you say you need it's ok for me.
I bump in a similar problem , I needed to add lines (trace lines) on a screen as fast as possible.
I made several experiment : listBox , listView, richTextBox , (even webBrowser ...)
It turns out that richTextbox was the fastest , and that the speed to add new line was constant , whatever was the numer of lines already added.
Of course in this case you shouldn't add lines one by ones , but all in one call.
Just set the rtb not to be editable.
Even handle the line selection by yourself.
And you will get a super fast , super basic ListBox 
Hope it helps
|
|
|
|
|
Hi girm,
thanks for your answer,
yes, sometimes it is necessary to add as many lines as mentioned.
I think Listbox ist the best option to use in this case.
my code snippet:
this.ListBox1.DisplayMember ="column";
this.ListBox1.DataSource =dt;//dt: DataTable
regards
Leia2011
|
|
|
|
|
Hello
I want to use some VC++ classes in C#... is it possible ???
If it is possible, then how ???
Thanks
Devesh Mishra
|
|
|
|
|
If you rewrite them as C++/CLI classes, it is. Otherwise, you have to convert to C#, or put them in a dll and you can then use methods in the dll, but not classes as such, via p/invoke.
Christian Graus - Microsoft MVP - C++
Metal Musings - Rex and my new metal blog
"I am working on a project that will convert a FORTRAN code to corresponding C++ code.I am not aware of FORTRAN syntax" ( spotted in the C++/CLI forum )
|
|
|
|
|
Hi
Try the following link on how to marshal c++ class
We have a similar concept that works at production environment
http://www.codeproject.com/csharp/marshalCPPclass.asp
|
|
|
|
|
I am not sure what to even call my question so I couldn't make a better subject. Sorry about that.
I have been making a custom web user control for sometime now and I am quite pleased with the results.
Only one more thing I want to get it to do. My control has a table in it with a method to add cells. I can add anything into the cells as I want as you would normally be able to with a table.
How can I get my control to allow this type of mark up as normal controls do?:
<table><asp:Button ID="btnTest" runat="server" /></table>
I want to be able to do this:
<custom:MyControl ID="myControl" runat="server"><asp:Button ID="btnTest" runat="server" /></custom:MyControl>
I want my control to add the button automatically by calling my code of choice. Any leads in the right direction greatly appriciated!
The best way to accelerate a Macintosh is at 9.8m/sec² - Marcus Dolengo
|
|
|
|
|
how to create partial class in c#.net ?
|
|
|
|
|
Do you even know what that means??
A partial class mearly exists acrossed two different source files, but you have to tell the compiler to expect the class to be define in multiple files using the partial modifier.
Read this[^] for everything you need to know about "partial classes".
|
|
|
|
|
Yes i know is different file! but my problem is how to insert a partial class in my project.? Thanks in advance.
|
|
|
|
|
Add a class. Add the partial keyword. Add another file, and edit it to be another partial file for the same class.
Christian Graus - Microsoft MVP - C++
Metal Musings - Rex and my new metal blog
"I am working on a project that will convert a FORTRAN code to corresponding C++ code.I am not aware of FORTRAN syntax" ( spotted in the C++/CLI forum )
|
|
|
|
|
You didn't bother the read the link I posted, did you?
|
|
|
|
|
R u a Student or Developer?
Partial Class is :
Using the partial keyword indicates that other parts of the class, struct, or interface can be defined within the namespace. All the parts must use the partial keyword. All of the parts must be available at compile time to form the final type. All the parts must have the same accessibility, such as public, private, and so on.
Regards,
Satips. ![Rose | [Rose]](https://codeproject.global.ssl.fastly.net/script/Forums/Images/rose.gif)
|
|
|
|
|
|
With a text editor.
|
|
|
|
|
|
Smile: A curve that can set a lot of things straight!
(\ /)
(O.o)
(><)
|
|
|
|
|
ROTFL
Regards,
Satips. ![Rose | [Rose]](https://codeproject.freetls.fastly.net/script/Forums/Images/rose.gif)
|
|
|
|
|
Hi all,
whenever use this little section of code i get a permission error. I have admin rights to all the boxes i want to check but im not sure how to pass admin credentials to the machines to can get use the GetProcesses method
code follows:
foreach (System.Diagnostics.Process proc in System.Diagnostics.Process.GetProcesses(MachineName))
{
try { textBox3.AppendText("Proc Name: " + proc.ProcessName.ToString() + " @ " + proc.StartTime.ToString() + "\n"); }
catch { }
}
|
|
|
|
General 
News 
Suggestion 
Question 
Bug 
Answer 
Joke 
Praise 
Rant 
Admin 
Submit an article or tip
