Re: Issues with Mutlithreading and STA - C# Discussion Boards

Re: Activation or License

TJoe4-Oct-07 12:11

TJoe

4-Oct-07 12:11

Hi Andrew,

Try taking a look at this article[^].

Take care,
Tom

-----------------------------------------------
Check out my blog at http://tjoe.wordpress.com

DataGridView button problem

udikantz4-Oct-07 9:20

udikantz

4-Oct-07 9:20

hello , im having a problem with the DataGridViewButtonColumn/DataGridViewButtonCell

i am trying to apend a button cloumn to my datagridview so everytime the user is clicking on one of the buttons in the grid an event will fire ,
i have noticed there is no access to events in the DataGridViewButtonColumn but there is an onClick protected method which fires when the user clicks the button, so i made my own class which drives from it and added my own event here is the code:

 <br />
public delegate void buttonClickHandler(DataGridViewCellEventArgs e);<br />
    class DataGridViewButton : DataGridViewButtonCell<br />
    {<br />
        public event buttonClickHandler buttonClick;<br />
<br />
        protected override void OnClick(DataGridViewCellEventArgs e)<br />
        {<br />
            if (buttonClick != null)<br />
            {<br />
                buttonClick(e);<br />
                this.DataGridView.InvalidateCell(this);<br />
            }<br />
            else<br />
            {<br />
                Console.WriteLine("button event was set to null");<br />
            }<br />
            base.OnClick(e);<br />
        }<br />
       <br />
       <br />
    }<br />

i used this DataGridViewButtonCell in my program like that:

<br />
.<br />
.<br />
.<br />
DataGridViewButtonColumn dgvBC = new DataGridViewButtonColumn();<br />
<br />
DataGridViewButton bc = new DataGridViewButton();<br />
bc.buttonClick += new buttonClickHandler(dgv_button_click);<br />
<br />
dgvBC.CellTemplate = bc;<br />
           <br />
dataGridView1.Columns.Add(dgvBC); <br />
.<br />
.<br />
.        <br />

The Problem:
each time the buttonClick Event fires when the user clicks on one the buttons in the datagridview
the event is for some reason is null , what did i do wrong?
is there any better way to do this? , any advice will be more than welcome , thanks!

Net

Issues with Mutlithreading and STA [modified]

Aaron VanWieren4-Oct-07 8:53

Aaron VanWieren

4-Oct-07 8:53

I am currently working on an app that requires large volumes of processing. The long story short, it was determined that threads would be the best way to split it up and increase performance of the application. Heres the catch: I have to use STA as the com objects used are registered as STA objects. Fun!

I ran a quick test with one STA/thread and two STA/threads both running the same code and the results show that the single thread was actually faster than using two threads. I figure this is due to the nature of the message queue and sequential processing. So my question is this, is there any way to have an STA that can process simultaneously without a performance decrease? My code is fairly simple:

 <br />
       ParameterizedThreadStart workerThread = new ParameterizedThreadStart(EditFeatureClass);<br />
       Thread protoThread = new Thread(new ThreadStart(ItterateFeatureClass));         <br />
                    protoThread = new Thread(workerThread);<br />
                    protoThread.SetApartmentState(ApartmentState.STA);                    <br />
                    protoThread.Name = featureName;<br />
                    protoThread.Priority = ThreadPriority.Highest;<br />
                    protoThread.IsBackground = true;<br />
                    protoThread.Start((object)featureName);<br />
<br />
                }

Any suggestions and comments would be appreciated (And no, I am stuck with STA).

I have posted a copy of the unedited document I have been working on in regards to this if it helps. It should be the second link - Thread Performance Testing.[^]
-- modified at 18:25 Thursday 4th October, 2007

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Re: Issues with Mutlithreading and STA

led mike4-Oct-07 9:52

led mike

4-Oct-07 9:52

Aaron VanWieren wrote:
it was determined

what do you mean "determined"? Does that mean "assumed"? I suggest Advanced Windows by Richter, it might be able to shine some light on your subject.

Re: Issues with Mutlithreading and STA

Aaron VanWieren4-Oct-07 10:34

Aaron VanWieren

4-Oct-07 10:34

It was the direction my boss said to go. Read some Richter, will look into that one.

Re: Issues with Mutlithreading and STA

Luc Pattyn4-Oct-07 11:57

Luc Pattyn

4-Oct-07 11:57

Hi,

you did not tell us much about ItterateFeatureClass. If all it does is call your COM
object, I am afraid the only way to get it really multi-threading is by providing multiple
identical COM objects, one per thread, assuming the functionality allows that.

The alternative of course would be putting the multithreading right inside the COM object
itself, but I guess that is not what you hope for.

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

this months tips:
- use PRE tags to preserve formatting when showing multi-line code snippets
- before you ask a question here, search CodeProject, then Google

Re: Issues with Mutlithreading and STA

Aaron VanWieren4-Oct-07 12:12

Aaron VanWieren

4-Oct-07 12:12

IterateFeatureClass() is just a test class for right now that performs a number of editing operations, which are set up through the COM objects. I would have included that code but it includes allot of third party library stuff that is registered as STA. I ran a test with two threads and my time doubled compared to my single thread test. I made sure to time the performance for just the iterations as well as the setup and tear down.

Basically my test code is creating a workspace(think database connection) and retrieving a featureclass(think table). From this feature class it creates an object and adds a feature(think row) then modifies a field(think column) and finally it stores it in the workspace. I am trying to explain this without getting too much into the library as it is different terminology. But I have ensured that all the COM Components are generated withing the STA thread.

Luc Pattyn wrote:
The alternative of course would be putting the multithreading right inside the COM object
itself, but I guess that is not what you hope for.

As this is a library I cannot modify I cannot do this.

The interesting this is that a colleague of mine attempted this and just through it together with MTA threads. In my testing I discovered this was the worst thing to do performance wise as it took the MTA thread 8 mins to do what an STA thread was doing in 4!

Hope this helped a little bit more.

Re: Issues with Mutlithreading and STA

Luc Pattyn4-Oct-07 12:39

Luc Pattyn

4-Oct-07 12:39

Hi Aaron,

if your CPU load is sufficiently low right now on both client and server (assuming DB on
separate machine here), the only thing I can think of that could improve overall elapsed time
is using multiple processes, each with one STA thread, again assuming the job can be split
in independent parts, that just share data at the database level. This would basically
cost additional CPU cycles to perform the remoting, but it would increase parallelism on
the DB operations.

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

this months tips:
- use PRE tags to preserve formatting when showing multi-line code snippets
- before you ask a question here, search CodeProject, then Google

Problems with opening Child Window in MDI

RichardAlbrecht4-Oct-07 8:23

RichardAlbrecht

4-Oct-07 8:23

I have a main form with menu options to open child forms within this main form window.
Problem I am seeing is that I get scroll bars when I do this. if I move around with the scroll bars they disappear and give me what I wanted.

Now if I make the menu invisible the child form opens correctly. But I need the menu bar so other child forms can be opened.

The goals is the following for every child form opened;
• Without scroll bars
• Without control box
• With the main menu bar still visible
• Child window docked nicely.

Does anyone have ideas as to why I am getting this behavior and how I can get the behavior I want?

Sample of the current code to open the child form from the main form.
private void menuBornEntry_Click(object sender, System.EventArgs e)
{
/// Performing Born Entry activity . . .
frmBornEntry dlgBornEntry = new frmBornEntry () ;
dlgBornEntry.MdiParent = this ;
dlgBornEntry.Activated += new EventHandler(ChildWindow_Opened);
dlgBornEntry.Closed += new EventHandler(ChildWindow_Closed);
dlgBornEntry.Dock = DockStyle.Fill ;
dlgBornEntry.Show () ;
}

Thanks
Rich

Re: Problems with opening Child Window in MDI

KaineDunno4-Oct-07 8:38

KaineDunno

4-Oct-07 8:38

try resizing your forms in design time.

think that could help... i dont see anything wrong in the posted code.

Greetings

Re: Problems with opening Child Window in MDI

RichardAlbrecht4-Oct-07 9:12

RichardAlbrecht

4-Oct-07 9:12

I tried resizing the child form but it ended up being too small in the main form window which is not the desired goal. no matter how I resized it I would have the child form either too small and get the scroll bars.

Thanks

Re: Problems with opening Child Window in MDI

Pete O'Hanlon4-Oct-07 10:40

Pete O'Hanlon

4-Oct-07 10:40

Set the WindowState of the child form to Maximized. This means that the child window will show maximized in the MDI frame - which will put the close/minimize/maximize buttons in the MDI frame window.

Deja View - the feeling that you've seen this post before.

Being more generic

Ryno Burger4-Oct-07 8:18

Ryno Burger

4-Oct-07 8:18

Hi guys

I wanna know how I could make the following function more generic and stop writing tedious code...

My current example function:

<br />
 public SqlCommand SetupCommand()<br />
        {<br />
            SqlCommand cmd = new SqlCommand();<br />
            cmd.CommandText = "SELECT * FROM Test";<br />
            cmd.CommandTimeout = 180;<br />
<br />
            return cmd;<br />
        }<br />

The above snippet of code will return a SqlCommand object. However there is cases where I would like this very same method but this time around returning a OleDbCommand object.

Is there a way to make this method more generic to be able to return any Command types e.g SqlCommand, OleDbCommand without having to re-write code all the time.

I guess I'm searching for something similar to IDataReader that can return either SqlDataReader or OleDbDataReader.

Thanks in advance.

R.

Re: Being more generic

MartyExodus4-Oct-07 8:42

MartyExodus

4-Oct-07 8:42

Wouldn't the easiest way be:

<br />
public DbCommand SetupCommand(bool isSql)<br />
{<br />
    if(isSql)<br />
    {<br />
        //Do SQL setup<br />
    }<br />
    else<br />
    {<br />
        //Do OleDb setup<br />
    }<br />
    return cmd;<br />
}<br />

There is no knowledge that is not power. - Mortal Kombat

Re: Being more generic

PIEBALDconsult4-Oct-07 9:09

PIEBALDconsult

4-Oct-07 9:09

Take a look at how I do that.

http://www.codeproject.com/cs/database/DatabaseAccessor.asp[^]

Re: Being more generic

PIEBALDconsult4-Oct-07 9:14

PIEBALDconsult

4-Oct-07 9:14

And also

http://www.codeproject.com/script/comments/forums.asp?msg=2202925&forumid=1649&XtraIDs=1649&searchkw=using+and+database&sd=1+apr+2007&ed=4+Oct+2007&author=PIEBALDconsult&stype=3#xx2202925xx[^]

Re: Being more generic

Pete O'Hanlon4-Oct-07 10:37

Pete O'Hanlon

4-Oct-07 10:37

If you are using .NET 2, take a look at the DB Provider classes that were introduced. These classes, such as DbCommand[^] are intended to provide you with a relatively database agnostic way of working with your data. You can get more detailed information here[^].

Deja View - the feeling that you've seen this post before.

Re: Being more generic [modified]

Nissim Salomon4-Oct-07 11:05

Nissim Salomon

4-Oct-07 11:05

Hi
Try using the following code
that use generics in order to construct the desired type sqlcommand

class Program
    {
        public static T SetupCommand<T>() where T : IDbCommand, new() 
        {
            T cmd = new T();
            cmd.CommandText = "SELECT * FROM Test";            
            cmd.CommandTimeout = 180;            
            return cmd;
        }
        
        static void Main(string[] args)
        {
            
            SqlCommand sqlClientCmd = SetupCommand<SqlCommand>();
            OleDbCommand oleDBCmd = SetupCommand<OleDbCommand>();
        }
    }

-- modified at 6:21 Friday 5th October, 2007

Post blog using C#

Phoen254-Oct-07 8:02

Phoen25

4-Oct-07 8:02

Hello. I want to post to a blog using C#, any have an idea of how to do that?

Thanks a lot !!!

Re: Post blog using C#

Judah Gabriel Himango4-Oct-07 9:13

Judah Gabriel Himango

4-Oct-07 9:13

That's insufficient information to give you a meaningful answer. What blog hosting service are you trying to post a blog to? Services like Blogger, for example, give a public API you can call via web services.

I recommend you figure out which blog hosting service to publish a blog post to, then go to that service's developer API site and figure out how to call their web service APIs via .NET.

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

Re: Post blog using C#

Pete O'Hanlon4-Oct-07 10:44

Pete O'Hanlon

4-Oct-07 10:44

Do you mean that you want to write a blogging engine in C#? If so, have a search on this site for Marc Clifton's articles on creating a simple blogging engine.

Deja View - the feeling that you've seen this post before.

Slide-down/up Menubar...

hostopolis4-Oct-07 7:25

hostopolis

4-Oct-07 7:25

I want to create a menubar or content box that sides up out of the way at the click of a button. It doesn't have to be a menu, per se, I can just place images and/or buttons in a sliding area. I just want to be able to click and have it slide up, or down, giving me access to the buttons when I need them.

reading byte[] instead of binary reader

Xmen Real 4-Oct-07 6:38