C# Discussion Boards - CodeProject

Re: Value Type vs. Ref Type

12-Sep-04 23:56

hi,
I don't know in which sence that you are asking 'Value Type or Reference Types are fast'. I recommand you to read some C# syntax and C# basics.
Value type and reference types are two type of Common Type System. We can say all numeric types are value type and which are stored in stack memory. Variables of reference types, referred to as objects, store references to the actual data. Reference type store data in Managed Heap memory.

And the visibility of both types are entirly different.

In some cases we need to convert value type to reference type or reverse. So this is also possible.

Converting value type data into reference type data is called BOXING.

Converting Reference type data into value type data is called UNBOXING.

I recommand you to read MSDN or some book which explain the C# language.

**************************
S r e e j i t h N a i r
**************************;)

Salil Khedkar13-Sep-04 1:33

Salil Khedkar

13-Sep-04 1:33

Objective answer: Value types are faster.

Notes:
If you have a finite (and preferably short) storage requirement, value types (for example a structure) are your best friends. But use them lavishly and you will end up with a Stack overflow.

My application is eating CPU

Stefan Bckman12-Sep-04 23:14

Stefan Bckman

12-Sep-04 23:14

Here is my problem:

I have done a web application; on this web application you can start a "slideshow". This slideshow consists of four pages that display data in tables and graphs. Each page get a lot of data from the database (SQL Server) and some of the pages use a lot of nestled ArrayLists to calculate the data before it's presented. Everything is done in c# and I use the data application block from MS.

The problem: I start the problem and the pages are displayed fine (the user can choose the delay in seconds before the next page are displayed, in this case 10 seconds). After 30 minutes - x hours Internet Explorer just hangs (the whole page turns white and no code is executed). No error turns up in my errorlog either.

I thought it had something to do with IE, so I've started to do a Windows Form application of this instead. The same (?) problem happens again. The program eats CPU and after 30-60 minuts the CPU is at 100% and the application almost stalls. I have run CLR Profiler but I don’t know how to read the results.

Can anyone help me how to get further with this problem? I’m starting to think if I have the same problem both on my web application and on my windows application? And if so, what is eating CPU? The pages are really simple, no multithreads, just get data in a dataset, transform the data and display it?

Thanks for any help, tips how to get further!

Rgds,
Stefan

Re: My application is eating CPU

Steve Maier13-Sep-04 4:41

Steve Maier

13-Sep-04 4:41

Could you either post or send that code so that we can see? It's hard to pinpoint your problem when its like this without seeing it.

Steve Maier, MCSD MCAD

Re: My application is eating CPU

Stefan Bckman13-Sep-04 4:48

Stefan Bckman

13-Sep-04 4:48

I got a tip that it might be that fact that I never dispose my datasets.

I have tried to dispose all datasets both in the windows version and the web version. No luck with the windows application though, still eats CPU.

When I test this I only use one page so the code is quite simple. We have one Main form that handles what page to show etc and one subform that displays the data.

Here is the code that is executed every 10 seconds from the main form:

private void timer2_Tick(object sender, System.EventArgs e)<br />
		{<br />
			YO.WindowState = FormWindowState.Maximized;<br />
			TS.WindowState = FormWindowState.Maximized;<br />
			MG.WindowState = FormWindowState.Maximized;<br />
			DG.WindowState = FormWindowState.Maximized;<br />
<br />
			string sTime =  dataContainer.getTime().ToString();<br />
			string sLimit =  dataContainer.getLimit().ToString();<br />
			string sVolume =  dataContainer.getVolume().ToString();<br />
			string sPages = dataContainer.getPages();<br />
			string sProducts = dataContainer.getProducts();<br />
			string sUnits = dataContainer.getUnits();<br />
<br />
			ArrayList arrPages = YieldMonitorEngine.ExtractPages(dataContainer.getPages());<br />
			ArrayList arrProducts = YieldMonitorEngine.ExtractProducts(dataContainer.getProducts());<br />
			<br />
			switch (int.Parse(sPageToView))<br />
			{<br />
				case AppConstants.MONITOR_YIELD_OVERVIEW: <br />
						<br />
					YO.InitializePage (int.Parse(sPageToView), int.Parse(sProductToView), int.Parse(sTime), <br />
						double.Parse(sLimit), int.Parse(sVolume), sPages, sProducts, sUnits);<br />
					MG.Hide();<br />
					DG.Hide();<br />
					TS.Hide();<br />
					YO.Show();<br />
					YO.Refresh();<br />
					YO.Update();<br />
					break;<br />
				case AppConstants.MONITOR_YIELD_DETAILS_MONTHLY_GRAPH:<br />
					MG.InitializePage (int.Parse(sPageToView), int.Parse(sProductToView), int.Parse(sTime), <br />
						double.Parse(sLimit), int.Parse(sVolume), sPages, sProducts, sUnits);<br />
					MG.Show();<br />
					MG.Refresh();<br />
					MG.Update();<br />
					YO.Hide();<br />
					DG.Hide();<br />
					TS.Hide();<br />
					break;<br />
				case AppConstants.MONITOR_YIELD_DETAILS_DAILY_GRAPH:<br />
					DG.InitializePage (int.Parse(sPageToView), int.Parse(sProductToView), int.Parse(sTime), <br />
						double.Parse(sLimit), int.Parse(sVolume), sPages, sProducts, sUnits);<br />
					DG.Show();<br />
					DG.Refresh();<br />
					DG.Update();<br />
					YO.Hide();<br />
					MG.Hide();<br />
					TS.Hide();<br />
					break;<br />
				case AppConstants.MONITOR_TOP_SYMPTOMS:<br />
					TS.InitializePage (int.Parse(sPageToView), int.Parse(sProductToView), int.Parse(sTime), <br />
						double.Parse(sLimit), int.Parse(sVolume), sPages, sProducts, sUnits);<br />
					TS.Show();<br />
					TS.Refresh();<br />
					TS.Update();<br />
					YO.Hide();<br />
					MG.Hide();<br />
					DG.Hide();<br />
					break;<br />
			}<br />
<br />
				<br />
			string sLastViewedProduct = sProductToView;<br />
			string sLastViewedPage = sPageToView;<br />
<br />
			//determine which page and product to view next<br />
			int iIndexOfLastViewedProduct = arrProducts.IndexOf(sLastViewedProduct.ToString());<br />
<br />
			//if there are more products to view for the current page just select the next product<br />
			if (iIndexOfLastViewedProduct + 1 < arrProducts.Count) <br />
			{<br />
				sProductToView = arrProducts[iIndexOfLastViewedProduct + 1].ToString();<br />
				sPageToView = sLastViewedPage;<br />
			}<br />
				//if this is the last product for this page we should select the first product and the next available page<br />
			else <br />
			{<br />
				sProductToView = arrProducts[0].ToString();<br />
<br />
				int iIndexOfLastViewedPage = arrPages.IndexOf(sLastViewedPage.ToString());<br />
<br />
				if (iIndexOfLastViewedPage + 1 < arrPages.Count) <br />
				{<br />
					sPageToView = arrPages[iIndexOfLastViewedPage + 1].ToString();<br />
				}<br />
				else <br />
				{<br />
					sPageToView = arrPages[0].ToString();<br />
				}<br />
			}<br />
<br />
			arrPages.Clear();<br />
			arrProducts.Clear();<br />
		}

When I test the application I only test with the case AppConstants.MONITOR_TOP_SYMPTOMS, so that's the code that is executed. The TS.InitializePage code looks like this:

		public void InitializePage (int iPageToView, int iProductToView, int iTime, double dLimit, int iVolume,<br />
			string sPages, string sProducts, string sUnits) <br />
		{<br />
			dgUnit1.DataSource = null;<br />
			dgUnit2.DataSource = null;<br />
			dgUnit3.DataSource = null;<br />
			dgUnit4.DataSource = null;<br />
		<br />
			DateTime dtTestDate = DateTime.Parse(DateTime.Now.AddDays(iNoDaysFromTodayToView).ToShortDateString());<br />
			//DateTime dtTestDate = DateTime.Parse("07/20/2004");<br />
			ArrayList arrProducts = YieldMonitorEngine.ExtractProducts(sProducts);<br />
			ArrayList arrUnitGroups = YieldMonitorEngine.ExtractUnitGroups(sUnits);<br />
			<br />
			//get the units to view for the current product<br />
			ArrayList arrUnitsForProduct = YieldMonitorEngine.ExtractUnitsForProduct(iProductToView, arrProducts, arrUnitGroups);<br />
<br />
			//get product data for the current product<br />
			DataSet dsProduct = YieldMonitorEngine.GetProductInfo(iProductToView);<br />
<br />
			if (dsProduct != null && dsProduct.Tables[0].Rows.Count > 0) <br />
			{<br />
				string sModelName = dsProduct.Tables[0].Rows[0][DBConstants.PRODUCT_MODEL].ToString();<br />
<br />
				//set page title<br />
				lblTitle.Text = "Top Symptoms for " + sModelName  + " - " + dtTestDate.ToString("MMMM d, yyyy");<br />
			}<br />
<br />
			if (arrUnitsForProduct.Count > 0) <br />
			{<br />
				//initalize datagrid 1<br />
				dgUnit1.Visible = true;<br />
				InitializeDataGrid(int.Parse(arrUnitsForProduct[0].ToString()), iProductToView, dtTestDate, dgUnit1, lblUnit1, dLimit, iVolume);<br />
			}<br />
			else <br />
			{<br />
				dgUnit1.Visible = false;<br />
			}<br />
<br />
			if (arrUnitsForProduct.Count > 1) <br />
			{<br />
				//initalize datagrid 2<br />
				dgUnit2.Visible = true;<br />
				InitializeDataGrid(int.Parse(arrUnitsForProduct[1].ToString()), iProductToView, dtTestDate, dgUnit2, lblUnit2, dLimit, iVolume);<br />
			}<br />
			else <br />
			{<br />
				dgUnit2.Visible = false;<br />
			}<br />
<br />
			if (arrUnitsForProduct.Count > 2) <br />
			{<br />
				//initalize datagrid 3<br />
				dgUnit3.Visible = true;<br />
				InitializeDataGrid(int.Parse(arrUnitsForProduct[2].ToString()), iProductToView, dtTestDate, dgUnit3, lblUnit3, dLimit, iVolume);<br />
			}<br />
			else <br />
			{<br />
				dgUnit3.Visible = false;<br />
			}<br />
<br />
			if (arrUnitsForProduct.Count > 3) <br />
			{<br />
				//initalize datagrid 4<br />
				dgUnit4.Visible = true;<br />
				InitializeDataGrid(int.Parse(arrUnitsForProduct[3].ToString()), iProductToView, dtTestDate, dgUnit4, lblUnit4, dLimit, iVolume);<br />
			}<br />
			else <br />
			{<br />
				dgUnit4.Visible = false;<br />
			}<br />
<br />
			dsProduct.Dispose();<br />
			arrProducts.Clear();<br />
			arrUnitGroups.Clear();<br />
			arrUnitsForProduct.Clear();<br />
		}<br />
<br />
<br />
		/// <summary><br />
		/// This method initializes and binds the unit datagrids<br />
		/// </summary><br />
		private void InitializeDataGrid(int iSupplyUnitID, int iProductID, DateTime dtTestDate, DataGrid dgUnit, Label lblUnit, double dSymptomLimit, int iMinStationVolume)<br />
		{<br />
			try <br />
			{<br />
				//set unit title<br />
				DataSet dsSupplyUnit = YieldMonitorEngine.GetSupplyUnitInfo(iSupplyUnitID);<br />
				if (dsSupplyUnit != null && dsSupplyUnit.Tables[0].Rows.Count > 0) <br />
				{<br />
					lblUnit.Text = dsSupplyUnit.Tables[0].Rows[0][DBConstants.SUPPLY_UNIT_SHORT_NAME].ToString();<br />
				}<br />
<br />
				DataSet dsTopSymptoms = YieldMonitorEngine.GetSymptomYieldDailySUMTopSymptoms(iSupplyUnitID, iProductID, dtTestDate, dSymptomLimit, iMinStationVolume);<br />
				dsTopSymptoms.Tables[0].TableName = "TopSymptoms"; <br />
				dgUnit.DataSource = dsTopSymptoms.Tables["TopSymptoms"];<br />
<br />
				if (dsTopSymptoms.Tables["TopSymptoms"].Rows.Count == 0)<br />
				{<br />
					dgUnit.Visible = false;<br />
				}<br />
				else<br />
				{<br />
					dgUnit.Visible = true;<br />
				}<br />
<br />
				dsTopSymptoms.Dispose();<br />
				dsSupplyUnit.Dispose();<br />
<br />
				dgUnit.Enabled = false;<br />
			<br />
				DataGridTableStyle dgts = new DataGridTableStyle();<br />
			<br />
				dgts = new DataGridTableStyle();<br />
				dgts.MappingName = "TopSymptoms";<br />
<br />
				dgts.AlternatingBackColor = Color.LightGray;<br />
<br />
				DataGridTextBoxColumn TextCol = new DataGridTextBoxColumn();<br />
				TextCol.MappingName = "SymptomName";<br />
				TextCol.HeaderText = "Symptom";<br />
				TextCol.ReadOnly = true;<br />
				TextCol.Width = 250;<br />
				dgts.GridColumnStyles.Add(TextCol);<br />
<br />
				TextCol = new DataGridTextBoxColumn();<br />
				TextCol.MappingName = "StationName";<br />
				TextCol.HeaderText = "Station";<br />
				TextCol.ReadOnly = true;<br />
				TextCol.Width = 250;<br />
				dgts.GridColumnStyles.Add(TextCol);<br />
<br />
				TextCol = new DataGridTextBoxColumn();<br />
				TextCol.MappingName = "YieldLossTest1";<br />
				TextCol.HeaderText = "Yield Loss";<br />
				TextCol.Format = "P";<br />
				TextCol.ReadOnly = true;<br />
				TextCol.Width = 250;<br />
				dgts.GridColumnStyles.Add(TextCol);<br />
<br />
				//change width of the row headers <br />
				dgts.RowHeadersVisible = false;<br />
 <br />
				// make the dataGrid use our new tablestyle and bind it to our table <br />
 				dgUnit.TableStyles.Clear();  <br />
<br />
				<br />
				dgUnit.TableStyles.Add(dgts);<br />
			}<br />
			catch (Exception ex) <br />
			{<br />
				string ssfsfs = "";<br />
//				lblError.Text = "Error on page: " + ex.Message;<br />
//				ExceptionManager.Publish(ex);<br />
			}<br />
		}

Can it be that I for some reason have some objects that I havn't disposed that I should? I thought .NET handled this automatically but seems like it wasn't that easy?

Bitmap object question...

theJazzyBrain12-Sep-04 22:54

theJazzyBrain

12-Sep-04 22:54

Dear CPians,

I have a problem within my ASP.NET application. The reason I am posting it on this Forum is that the problem is not Web related, its 100% C#.

I upload an image and I create an Image object from it. I do some Image manipulation like rescaling, rotating etc. and I create a Bitmap object from it.
Then I create another Bitmap object which is the Thumbnail of the first one.

I end up with two Bitmap objects. The original one and the thumnail. Now I need to save the two into the DataBase, (SQL Server 2000).

How can I convert the two Bitmap objects into byte arrays (byte[])? Any ideas?

Thanking you in advance! Big Grin | :-D

theJazzyBrain

Excellence is not an act, but a habit!

Aristotle

Re: Bitmap object question...

David Salter13-Sep-04 0:23

David Salter

13-Sep-04 0:23

This article shows how to store and retrieve bitmaps in a database via a byte[].

http://www.codeproject.com/cs/database/albumviewer.asp?df=100&forumid=3653&exp=0&select=775463[^]

store your internet favourites online - www.my-faves.co.uk

system information

ozgul12-Sep-04 21:29

ozgul

12-Sep-04 21:29

How can i get system information, such as ip adresses,hdd properties, directories...etc of a local computer? D'Oh! | :doh:

Can u give some examples?
Please help me
Tahnks everybody

Re: system information

pbpb12-Sep-04 22:12

pbpb

12-Sep-04 22:12

For example:System.Windows.Forms.MessageBox.Show(Environment.CurrentDirectory);

Re: system information

Dave Kreskowiak13-Sep-04 6:04

Dave Kreskowiak

13-Sep-04 6:04

You would have to get most, if not all, of this information using the System.Management namespace and WMI (Windows Manangement Instrumentation).

You can find examples of this on CP if you just search the Articles for 'WMI'. One example is right here[^].

RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome

Install of an add-in

Anonymous12-Sep-04 20:22

Anonymous

12-Sep-04 20:22

I made an addin by using the Addin-Wizard of Visual .NET.
I should like to install this addin on the next configuration:
- A PC with Windows XP
- there can be several users, but they haven't administrator rights.
- The installation of the addin must work in the administrator mode, but users should use it in restricted mode (not admin mode in Windows XP).
So, I have problems, because the addin fail when it is launched in restricted mode.
Visual .Net print the addin failed during the loading.
Do you know a solution for this problem ?

problem with gacutil

amalatsliit12-Sep-04 20:20

12-Sep-04 20:20

i have problem with these topics:
why we r put signing key for the assebly.
ok i have created a class library called empobject.it's locating F:\KeyTest\EmpObject

then i have assign a key:
D:\WINDOWS\System32>sn -k F:\KeyTest\EmpObject\mykey.snk and the key is generated.then i have create a folder called SpecialLib in
D:\Program Files\Microsoft Visual Studio .NET\FrameworkSDK\SpecialLib cas
i want to copy all the non standard component here.

then i promt D:\Program Files\Microsoft Visual Studio .NET\FrameworkSDK\SpecialLib>gacutil -i empobject.dll.

but thr was a error called
Microsoft (R) .NET Global Assembly Cache Utility. Version 1.0.3705.0
Copyright (C) Microsoft Corporation 1998-2001. All rights reserved.

Failure adding assembly to the cache: Attempt to install an assembly without a strong name

sreejith ss nair12-Sep-04 20:31

12-Sep-04 20:31

hi,

Did you mention the strongkey name and location in AssemblyInfo.cs file of your .dll project.

Eg. please mention the vales for the below mentioned assembly attributes.

[assembly: AssemblyKeyFile("")]
[assembly: AssemblyKeyName("")]

After mentioning this. Try to compile your .dll file once again and then use Gacutil to install this .dll into GAC.
Wink | ;)

**************************
S r e e j i t h N a i r
**************************

amalatsliit12-Sep-04 20:38

12-Sep-04 20:38

ya i don't have idea about the
[assembly: AssemblyKeyFile("")]
[assembly: AssemblyKeyName("")]

sreejith ss nair12-Sep-04 20:56

12-Sep-04 20:56

hi,

You will get this attibute on your AssemblyInfo.cs file which is located in your .dll project directory.

Before compiling your .dll you need to mention your strongkey file name and location. Just mention these information here and compile your assembly.

After your successful compilation you can go for Gacutil.

Eg.

[assembly: AssemblyDelaySign(false)]
[assembly: AssemblyKeyFile("C:\\Sreejit.snk")]
[assembly: AssemblyKeyName("Sreejit.snk")]

Here

AssemblyKeyFile - > the location where my Strongkey file is locating.

AssemblyKeyName - > is the name of strong file.

Try to compile your .dll after mentioning these two attribute. After this you can gacutil to install your .dll into GAC.

**************************
S r e e j i t h N a i r
************************** Big Grin | :-D

amalatsliit13-Sep-04 0:09

13-Sep-04 0:09

hello mr.sreejithnair,
Sorry about the mail.anyway i have install it sucessfully
but still i can't put it to the my own dir.cas i have create a dir
in my c:\.wht i want is copy all the non standard asemblies here.

thanx

amal

sreejith ss nair13-Sep-04 0:13

13-Sep-04 0:13

hi,

You wrote :
Sorry about the mail.

Nevar a problem. I won't encourage personal mails.

You can submit your doubt here in discussion. Sometimes this may help others.

I can't properly figurout what you mean by "non standard asemblies".

Tell me what is your real requirement.
Wink | ;)

**************************
S r e e j i t h N a i r
**************************

amalatsliit13-Sep-04 0:22

13-Sep-04 0:22

i just want to keep my own dll's in another seperate folder other than c:\windows\assembly.
and i have open a new project and i have to add reference above dll.

but my empobject.dll is not display in the component list under the .net tab.
but other standard dll's(Crystalreportplugindil) list thr.so wht was the problem.

amal

sreejith ss nair13-Sep-04 0:40

13-Sep-04 0:40

hi,

According me ,after completing your this requirement you need to study something about C# assemblies. Especially private and public assemblies.

The assemlies which are installed in GAC will show in the component list. But here you kept your assembly in your own location ( NOT IN GAC ). So it is upto you to locate the location of the .dll file.

Here what you can do is , Right click the reference folder and try to select add reference. Here you need to browse the location of your .dll file ( C:\yourDir\aaa.dll) and open.

So click on browse button and try to locate, open the .dll file.

After this you will came to know that your .dll is there in reference folder of your application.

Wink | ;)

Finally don't forget to study about Private and Shared Assemblies.

**************************
S r e e j i t h N a i r
**************************

ThreadStart

sreejith ss nair12-Sep-04 20:14