C# Discussion Boards - CodeProject

Re: Adding a List to a List with AddRange

Andrew Rissing14-Aug-06 6:58

14-Aug-06 6:58

Try using:

lstA.AddRange(lstB.ToArray());

What object type is the __items using? I hope its of object.

I would suggest not using the LoadEntries call at all to ensure what exactly the problem is. Separate your code into parts and try things you know work, until you find out what breaks it.

Good luck.

Re: Adding a List to a List with AddRange

Ista14-Aug-06 7:03

Ista

14-Aug-06 7:03

Andrew Rissing wrote:
Try using:

lstA.AddRange(lstB.ToArray());

What object type is the __items using? I hope its of object.

I would suggest not using the LoadEntries call at all to ensure what exactly the problem is. Separate your code into parts and try things you know work, until you find out what breaks it.

Good luck.

Ok. I'm trying to remain relaxed on this one.

So, I did what you said and I have this:

List<object> bb = new List<object>();

__items.AddRange(bb);

Please pick this apart and say what I'm doing wrong.

Thanks,
Nick

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Re: Adding a List to a List with AddRange

Andrew Rissing14-Aug-06 8:34

Andrew Rissing

14-Aug-06 8:34

Nick,

I would double check that __items is of List<object>. What is the compiling error that you're getting?

I'm trying to help, but it just seems you've got something else going on here that is either really simple (mismatch on type, an overloaded class/method, etc.) or something out of your hands like a compiler issue.

Re: Adding a List to a List with AddRange [modified]

Ista14-Aug-06 9:41

Ista

14-Aug-06 9:41

public class ForumList<T> : IEnumerable {
protected List<T> __items = new List<T>();

... code ...

List<T> bb = new List<T>();
__items.AddRange(bb);

Okay so this worked.

but, if say i do this:

List<T> bb = new List<T>();
List<object> cc = new List<object>();

bb.AddRange(cc);

it wont work. It must be explictly created as type of "T". Is there a way through, maybe reflection, that I can add these dynamically?

The problem I have is that the LoadEntries has no knowledge of the Entry class the template value is. SO I would need to create it on the fly. Otherwise I get a circular reference issue.

-- modified at 15:52 Monday 14th August, 2006

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1 line of code equals many bugs. So don't write any!!

My mad coder blog

Re: Adding a List to a List with AddRange

Andrew Rissing14-Aug-06 10:04

Andrew Rissing

14-Aug-06 10:04

You'll have to convert the list coming out of the function then to the proper type.

Try using ConvertAll on the List instance or perhaps by iterating over the list and type casting by hand. Either will do...

Re: Adding a List to a List with AddRange

Ista14-Aug-06 10:11

Ista

14-Aug-06 10:11

Hey, thanks for all your help. I think I have it working now.

Nick

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1 line of code equals many bugs. So don't write any!!

My mad coder blog

how to make a mp3 playlist and play the songs [modified]

aeliminate14-Aug-06 3:58

aeliminate

14-Aug-06 3:58

hi friends, i am doing a project on windows media player using c#. i know how to play mp3 songs but i'm unable to make a mp3 songs playlist. can any one help me with code.
thank you.

-- modified at 11:04 Monday 14th August, 2006

Re: how to make a mp3 playlist and play the songs

Judah Gabriel Himango14-Aug-06 4:59

Judah Gabriel Himango

14-Aug-06 4:59

Open up an WMP playlist file (.wpl) and see its format. You could easily output a compatible format using the XML writing classes contained in System.Xml namespace.

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Re: how to make a mp3 playlist and play the songs

aeliminate14-Aug-06 5:32

aeliminate

14-Aug-06 5:32

hi Himango

I am doing a project on windows media player using c#. i know how to play mp3 songs but i'm unable to make a mp3 songs playlist. can you help me with code.

Thankyou.

madhav

Re: how to make a mp3 playlist and play the songs

Judah Gabriel Himango14-Aug-06 5:42

Judah Gabriel Himango

14-Aug-06 5:42

Do you want to build an MP3 playlist for Windows Media Player? If so, all you have to do is look at the format of the .wpl file type. OPen up a .wpl file in a text editor, it's pretty straightforward; it's just an XML formatted document containing the path to the MP3s you want in the playlist.

Once you have that, you can use classes inside the XML namespace to write an XML document containing the MP3s. If you need help with how to create an XML document from code, I suggest you start a new thread.

Tech, life, family, faith: Give me a visit.
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Judah Himango

C# compiling doubt

cuser_id14-Aug-06 3:40

cuser_id

14-Aug-06 3:40

A.I added the Sln file which is present in the normal test command plugin directory.
File->new project->
Then add existing items ->testcommand.sln
Rt click on the windows explorer->build
1.Entry point not defined error.

Re: C# compiling doubt

Judah Gabriel Himango14-Aug-06 4:57

Judah Gabriel Himango

14-Aug-06 4:57

Is testcommand.sln a solution that builds an .exe? If so, you'll need a static void Main(string[] args) method.

Tech, life, family, faith: Give me a visit.
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Multithreading, Timers and flickering ListView

Tomi8714-Aug-06 3:30

Tomi87

14-Aug-06 3:30

Hi,

I have an application which gets info about system (for example running applications, processes, services, CPU info, OS info, ...). I create ProgressBar which will shows CPU usage (using WMI class to get actual usage). Then I create Timer (System.Windows.Forms.Timer) and set tick interval to one second. To get CPU usage and refresh ProgressBar to current usage value results to flicking in ListViews, when user wants to move with ScrollBar. Because of flicking I decided to create special thread for getting CPU usage and ProgressBar refresh to eliminate flicking. I create a new thread in constructor:

<br />
Thread threadRefresh = new Thread(new ThreadStart(Updating));<br />
threadRefresh.Start();<br />

which calls Updating method:

<br />
private void Updating() {<br />
            refreshTimer.Tick += new EventHandler(RefreshCPUUsage);<br />
            refreshTimer.Interval = 1000;<br />
            refreshTimer.Start();<br />
}<br />

Method RefreshCPUUsage finally refresh ProgressBar:

<br />
private void RefreshCPUUsage(Object myObject, EventArgs myEventArgs) {<br />
     manClass = new ManagementClass("Win32_PerfFormattedData_PerfOS_Processor");<br />
     manObjectCollection = manClass.GetInstances();<br />
               <br />
     foreach (ManagementObject CPU in manObjectCollection) {<br />
         progressBarCPU.Value = (int)Convert.ToUInt64(CPU.GetPropertyValue("PercentProcessorTime"));<br />
         progressBarCPU.PerformStep();<br />
         labelCPUPercent.Text = CPU.GetPropertyValue("PercentProcessorTime").ToString() + " %";<br />
     }<br />
}<br />

This solution doesn't work, so I tried to do other based on System.Threading.Timer and Tread pool. In constructor:

<br />
WaitCallback myThreadMethod = new WaitCallback(Updating);<br />
ThreadPool.QueueUserWorkItem(myThreadMethod);<br />

Updating method:

<br />
private void Updating(Object stateInfo) {<br />
    refreshTimer.Interval = 1000;<br />
    refreshTimer.Elapsed += new ElapsedEventHandler(RefreshCPUUsage);<br />
    refreshTimer.Start();<br />
}<br />

This is working but flickering in ListViews remains. I think that special thread for timer and refreshing can dispose flickering but it fails. Probably I'm doing somewhere mistake, but I don't know where. Please help me.

Re: Multithreading, Timers and flickering ListView

Ista14-Aug-06 3:43

Ista

14-Aug-06 3:43

The problem isn't with the thread, its with the painting of the control.

You can problably set the DoubleBuffer property to true to alleviate this.

If it doesn't, then Look at your paint event.

Inside this event you probably have a method that is called that isnt returned immediately thus, cause the flicker.

Find a way to call it at some other point in time.

If your still stuck, then try exctending the List view and override the OnPaintBackground method. This redraws the control background. Warning tho. If you dont redraw the background you will see whats behind the control you dont paint that pixel.

The reason you see flicker is because of this>
The control calls OnPaintBackground. It then paints the control white or whatever the back color is

Then it calls your paint event. If the time it takes between the PaintBackground and end of the paint event. Then your eye perceives this as flicker.

Good luck

Nick

--------------------------------------------------------

1 line of code equals many bugs. So don't write any!!

My mad coder blog

Re: Multithreading, Timers and flickering ListView

Tomi8714-Aug-06 8:31

Tomi87

14-Aug-06 8:31

I have tried to use DoubleBuffer, but flickering remains. The area of ListView is not flickering but when Timer tick event occur and user is moving with scrollbar at that time, then scrollbar stops for a while and then continue in scrolling (lonely ListView is not redrawing or doing anything else). It seems that getting actual CPU usage info is demanding and because of that I tried to create special thread for timer and CPU usage info.

"Documentation is like sex: when it is good, it is very, very good; and when it is bad, it is better than nothing."

Re: Multithreading, Timers and flickering ListView

Ista14-Aug-06 9:51

Ista

14-Aug-06 9:51

Have you tried calling Invalidate() and/or Application.DoEvents();

--------------------------------------------------------

1 line of code equals many bugs. So don't write any!!

My mad coder blog

Re: Multithreading, Timers and flickering ListView

Tomi8714-Aug-06 23:59

Tomi87

14-Aug-06 23:59

Yes I tried both, but problem remains. I don't need to redraw or repaint whole area of ListView but only to stop scraping of ScrollBar when refreshing occur.

=================================================
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Dick Brandon

T namespace is not found

Ista14-Aug-06 3:26

Ista

14-Aug-06 3:26

I have created a method

public MyMethod( T myType ){}

But, it says T is not recognized.

Which namespace and Dll must I include to get T into my project ( Generics )

--------------------------------------------------------

1 line of code equals many bugs. So don't write any!!

My mad coder blog

Re: T namespace is not found

JoeSharp14-Aug-06 3:40

JoeSharp

14-Aug-06 3:40

hi
try this:

using System.Collections.Generic;

Re: T namespace is not found

Ista14-Aug-06 3:42

Ista

14-Aug-06 3:42

I have this

using System;
using System.Collections.Generic;
using System.Text;
using System.Reflection;
using System.Data;
using System.Data.SqlClient;
using System.Data.SqlTypes;
using System.Configuration;
using System.Collections;
using System.Runtime.Serialization;

--------------------------------------------------------

1 line of code equals many bugs. So don't write any!!

My mad coder blog

Re: T namespace is not found

Josh Smith14-Aug-06 3:46

Josh Smith

14-Aug-06 3:46

Is that method in a generic class? If not, T won't be recognized, no matter what namespaces you include (unless you actually were to create a type named T).

:josh:
My WPF Blog[^]

Re: T namespace is not found

Ista14-Aug-06 3:56

Ista

14-Aug-06 3:56

k, thanks.

thats the problem

--------------------------------------------------------

1 line of code equals many bugs. So don't write any!!

My mad coder blog

Re: T namespace is not found

Colin Angus Mackay14-Aug-06 4:00

Colin Angus Mackay

14-Aug-06 4:00

T is the name of the generic template. However, it doesn't know that because you've not told it that T is a generic template, so it treats it as a real type. Since you don't have a type called T it causes an error

Ista wrote:
public MyMethod( T myType ){}

Also, this is not the code you have - This code won't compile for reasons other than those you've specified.

public void MyMethod<T>(T myType){}

public class MyClass<T>
{
    public void MyMethod(T myType) {}
}

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dataset computation

Saamir14-Aug-06 2:57

Saamir

14-Aug-06 2:57

Hi guys,
I need some help please, I am a newbie with C# and I am stuck on something.

I am using dataset to get data from the database, here is some bits of my code

SqlDataAdapter adp= new SqlDataAdapter();
DataSet ds=new DataSet();
adp.Fill(ds,"tbACJE");

if(ds.Tables["tbACJE"].Rows.Count>1)
{
System.Data.DataRow rd= ds.Tables["tbACJE"].Rows[0];
Double fTemp= 0.0;
fTemp=double.Parse(ds.Tables["tbACJE"].Compute("SUM(rd[0] + rd[1])", "").ToString());

What I am trying to do is
1) if there are more than 1 rows get the sum of the first 2 columns and if it's zero than Message and if not zero than get the difference amount.

Please help???

sasa

LoaderLock was detected

Johan Russouw14-Aug-06 2:53

Johan Russouw

14-Aug-06 2:53

Hi I'm using function in a dll written in C++ / MFC Visual Studio 6.
This use to work fine in the .NET framework 1.1, but I upgraded to Visual Studio 2005 and when I use any function from the dll I get a message 'LoaderLock was detected'. Are there any work around without changing the API?

Cheers Johan

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