Web Services and Files - C# Discussion Boards

Creating new object in another thread, then BeginInvoke that object?

Matthew Klein6-Mar-09 4:13

6-Mar-09 4:13

Greetings all!

My question:
From the main thread, how can I create two additional threads, each containing an object that will sit around and wait to be invoked? I want to do this because I don’t want the objects to be created and destroyed between invokes.

This is what I would like to do:
Have a main interface and two objects. The main form has 10 things it wants the objects to do, so upon starting it sends an item to each object via BeginInvoke (the objects are controls) to work and as soon as one of the objects is finished with an item, the main thread sends that object the next item to work, until all 10 are done.

Any help you can provide is much appreciated.

Thank you!

Re: Creating new object in another thread, then BeginInvoke that object?

Curtis Schlak.6-Mar-09 4:20

Curtis Schlak.

6-Mar-09 4:20

If by "the objects are controls" you mean "the objects are System.Windows.Forms.Controls" and you have your controls doing something business-y, then I think that you're wrong in your design and should look at something like the the ThreadPool class[^].

Furthermore, if those controls are Controls, then any updating that you want to do will have to be marshaled across thread boundaries back to the GUI thread.

"we must lose precision to make significant statements about complex systems."
-deKorvin on uncertainty

Re: Creating new object in another thread, then BeginInvoke that object?

Matthew Klein6-Mar-09 5:55

Matthew Klein

6-Mar-09 5:55

Thank you for the response!

The objects are System.Windows.Forms.WebBrowser that have been made a child on their own form. What I would like to do is make two of these forms in their own threads, then BeginInvoke the WebBrowser to do the work I need.

Re: Creating new object in another thread, then BeginInvoke that object?

Curtis Schlak.6-Mar-09 6:59

Curtis Schlak.

6-Mar-09 6:59

Well, that sounds great. I think that you should do that.

"we must lose precision to make significant statements about complex systems."
-deKorvin on uncertainty

Re: Creating new object in another thread, then BeginInvoke that object?

Curtis Schlak.6-Mar-09 7:40

Curtis Schlak.

6-Mar-09 7:40

D'oh! Threads, not processes!

That won't work. Windows requires all painting to occur on the UI thread. If it's somewhere else, then you'll get lots of .NET exceptions.

"we must lose precision to make significant statements about complex systems."
-deKorvin on uncertainty

Re: Creating new object in another thread, then BeginInvoke that object?

Dave Kreskowiak6-Mar-09 7:15

Dave Kreskowiak

6-Mar-09 7:15

Anticast wrote:
What I would like to do is make two of these forms in their own threads,

Nope. Won't work. The forms will not paint properly on anything other than the UI thread. The browser components will also have nasty issues work on a background thread, if they work for you at all.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007, 2008

Re: Creating new object in another thread, then BeginInvoke that object?

Dan Neely6-Mar-09 8:35

Dan Neely

6-Mar-09 8:35

As others have said you have to do all UI work in the UI thread. What you can do is to create worker threads for each form and have them do all the data crunching and then give the results back to the UI thread in order to display them. The only way you could get the forms into separate threads is to make each form a separate process entirely and use IPC to communicate between them and your main app.

Today's lesson is brought to you by the word "niggardly". Remember kids, don't attribute to racism what can be explained by Scandinavian language roots.
-- Robert Royall

Web Services and Files

cdpace6-Mar-09 3:49

cdpace

6-Mar-09 3:49

Hello people, I have a project where i need to pass a file approx 2.68Gb or larger from one application to another. Now the problem is that in my project i have to use web services to do this operation.

I currently have the following setup in my code:

BinaryReader binReader = new BinaryReader(File.Open(parser.TemporaryFilesPath + "\\database.zip", FileMode.Open, FileAccess.Read));
                           binReader.BaseStream.Position = 0;
                           byte[] binaryfile = binReader.ReadBytes(Convert.ToInt32(binReader.BaseStream.Length));

                           binReader.Close();


                           sc.Helllo(binaryfile);

The above code is in my first application. Than in my web service appliciton i have the following code that writes the binary file to the temp location where it is stored.

[WebMethod]
        public void Helllo(byte[] fileinbytes)
        {
            XMLParser parser = new XMLParser();
            parser.CreateTemporaryDirectory();

            BinaryWriter binWriter = new BinaryWriter(File.Open(parser.TemporaryFilesPath + "\\database.zip", FileMode.Create,FileAccess.ReadWrite));
            binWriter.Write(fileinbytes);
            binWriter.Close();

            parser.Unzip();
            parser.DecryptFiles();

            parser.MergeXMLDataToDatabae("Centre to Main Database");


        }

Now the problem is here in the first code block when the database.zip file increases in size its giving me the error "Value was either too large or too small for an Int32".Do you think there is a way which i can work around this or another way in which i cna program this. Thank you for your help and time guys apprciate it.

Re: Web Services and Files

Curtis Schlak.6-Mar-09 4:08

Curtis Schlak.

6-Mar-09 4:08

How about if you read the ZIP file into a buffer smaller than

int.MaxValue. Then, you can just loop until you've read it all.<br />
<br />
Just my $0.02, you should probably think of another way to do this than sending a > 2Gb file across the wire every time. <br />
<br />
<div class="ForumSig">"we must lose precision to make significant statements about complex systems."<br />
-deKorvin on uncertainty</div>

UTF-8 Not Displaying Unicode

Tim Beck6-Mar-09 3:21

Tim Beck

6-Mar-09 3:21

I use XmlTextReader to parse a supplied xml file. It is UTF-8 encoded, but a string read from a CDATA section does not display as a Unicode string.

Here is a very stripped down version of the xml file:

<?xml version="1.0" encoding="UTF-8"?>
<QuestionnaireDoc JobNo="New 1341 C" Description="New 1341 C" Week="2009-03-02" Template="DEV">
<QuesGroup Name="Tracks">
<TrackStudy Type="T" AdId="39240" Track="2">
<Title><![CDATA[Great Wall]]></Title>
<Content><![CDATA[It doesnâ?²t taste very good. Try xx Ciderâ?¢.]]></Content>
</TrackStudy>
</QuesGroup>
</QuestionnaireDoc>

The ReadString() method is used as follows:

o.Content = reader.ReadString(); // o.Content is String

o.Content contains "It doesnâ?²t taste very good. Try xx Ciderâ?¢.", not "It doesn′t taste very good. Try xx Cider™"

I've tried:

UTF8Encoding utf8 = new UTF8Encoding();
Byte[] encodedBytes = utf8.GetBytes(o.Content);
o.Content = utf8.GetString(encodedBytes);

but that makes no difference.

How do I decode this string? I have no control over the supplied xml file.

Re: UTF-8 Not Displaying Unicode

Curtis Schlak.6-Mar-09 4:05

Curtis Schlak.

6-Mar-09 4:05

I don't think that it's the reader, I think that it's the renderer.

For example, if you're reading this content and rendering it in a browser that does not have UTF-8 as the default character set and you haven't used the META tag to set the character set or passed it as an HTTP header, then it will display badly.

Look at your renderer. The code looks fine.

"we must lose precision to make significant statements about complex systems."
-deKorvin on uncertainty

Re: UTF-8 Not Displaying Unicode

Guffa6-Mar-09 6:26

Guffa

6-Mar-09 6:26

I tried it, and with your file containing correctly UTF-8 encoded text it works without problems. I think that the text in the file isn't actually encoded as UTF-8, or that you have decoded UTF-8 as ANSI and then encoded the corrupted string as UTF-8.

Tim Beck wrote:
I've tried:

UTF8Encoding utf8 = new UTF8Encoding();
Byte[] encodedBytes = utf8.GetBytes(o.Content);
o.Content = utf8.GetString(encodedBytes);

but that makes no difference.

Of course it doesn't. You are just encoding the string to UTF-8 and then decoding it again. That doesn't change how it's decoded when you read it from the file.

Despite everything, the person most likely to be fooling you next is yourself.

about array and property

clj198705036-Mar-09 2:59

clj19870503

6-Mar-09 2:59

if i use this code, do it have no sense

private int[] testProtery = new int[3];

public int[] TestProtery
{
get
{
return this.testProtery;
}
set
{
this.testProtery = value;
}
}
i want to uee the property to match the private filed of testProtery,
i feel this code don't work. please let me understand. thank you

Re: about array and property

musefan6-Mar-09 3:15

musefan

6-Mar-09 3:15

clj19870503 wrote:
i feel this code don't work

why would it not work?

If only MySelf.Visible was more than just a getter...

A person can produce over 5 times there own body weight in excrement each year... please re-read your questions before posting

Re: about array and property

Xmen Real 6-Mar-09 3:24

Xmen Real

6-Mar-09 3:24

sure, it'll work.

TVMU^P[[IGIOQHG^JSH`A#@`RFJ\c^JPL>;"[,*/|+&WLEZGc`AFXc!L
%^]*IRXD#@GKCQ`R\^SF_WcHbORY87֦ʻ6ϣN8ȤBcRAV\Z^&SU~%CSWQ@#2
W_AD`EPABIKRDFVS)EVLQK)JKSQXUFYK[M`UKs*$GwU#(QDXBER@CBN%
Rs0~53%eYrd8mt^7Z6]iTF+(EWfJ9zaK-iTV.C\y<pjxsg-b$f4ia>
--------------------------------------------------------
128 bit encrypted signature, crack if you can

Re: about array and property

clj198705036-Mar-09 3:58

clj19870503

6-Mar-09 3:58

for exampel , do i use this :
this.testProtery[0].TestProtery;

i don't understand, thank you .

Re: about array and property

musefan6-Mar-09 4:11

musefan

6-Mar-09 4:11

well it depends what you want to access?

if you have, for example, an array of string for different data you might do something like the following.

private string[] stringData = new string[2];

public string Name{
    get{return stringData[0];
    set{stringData[0] = value;
}

public string JobTitle{
    get{return stringData[1];
    set{stringData[1] = value;
}

thou in this instance you would prob want to have two different string instances for the data

Life goes very fast. Tomorrow, today is already yesterday.

Re: about array and property

Curtis Schlak.6-Mar-09 4:15

Curtis Schlak.

6-Mar-09 4:15

Ok, stay with me on this. Let's say that you have

public class TestClass
{
  private int[] _field;
}

Now, in a method of TestClass, you would have the following to reference the value of _field.

public class TestClass
{
  public void DoSomethingWithTheField()
  {
    if(null == _field)
    {
      this._field = new int[3]; // or just _field = new int[3];
    }
  }
  private int[] _field;
}

Now, let's add a property that allows getting and setting on _field.

public class TestClass
{
  public int[] Property
  {
    get { return _field; }
    set { _field = value; }
  }

  public void DoSomethingWithTheField()
  {
    if(null == _field)
    {
      this._field = new int[3]; // or just _field = new int[3];
    }
  }
  private int[] _field;
}

Now, you can have a method that will do something like this.

public class TestClass
{
  public void DoSomethingWithTheProperty(int secondValue)
  {
    this.Property[1] = secondValue; // or Property[1] = secondValue;
  }

  public int[] Property
  {
    get { return _field; }
    set { _field = value; }
  }

  public void DoSomethingWithTheField()
  {
    if(null == _field)
    {
      this._field = new int[3]; // or just _field = new int[3];
    }
  }
  private int[] _field;
}

You see? When you expose a property as an array of integers, you can just use it like an array of integers.

"we must lose precision to make significant statements about complex systems."
-deKorvin on uncertainty

Re: about array and property

Cybernate6-Mar-09 8:55

Cybernate

6-Mar-09 8:55

I am not getting your question.
The above post is rather a statement.
Can you be a little more specific?

Regards,
Chandra V

Re: about array and property

Curtis Schlak.6-Mar-09 9:35

Curtis Schlak.

6-Mar-09 9:35

I have no question.

I posted a statement.

I walked through the creation of a class with a field of type "integer array," a property that exposed it, and then methods that consume each. It answers the original poster's "how do I access this" question.

"we must lose precision to make significant statements about complex systems."
-deKorvin on uncertainty

Re: about array and property

Cybernate6-Mar-09 9:38

Cybernate

6-Mar-09 9:38

Thanks...

Regards,
Cybernate

Re: about array and property

Curtis Schlak.6-Mar-09 9:42

Curtis Schlak.

6-Mar-09 9:42

You're welcome.

"we must lose precision to make significant statements about complex systems."
-deKorvin on uncertainty

Disabling Crystal login

twsted f86-Mar-09 2:56

twsted f8

6-Mar-09 2:56

Hi

I was wondering, is it possible to disable the logon screen when using crystal reports. I would like my app to logon the user automatically. Is this possible and if so how would I go about this?

Kind Regards

F8

Re: Disabling Crystal login

ABitSmart6-Mar-09 3:27

ABitSmart

6-Mar-09 3:27

I am not sure which Login you are talking about. But see if this[^] helps.

Re: Disabling Crystal login

monstale6-Mar-09 5:08

monstale

6-Mar-09 5:08

Hi,

if you are using CrystalDecisions.CrystalReports.Engine.ReportDocument you can set user name and password with the property DataSourceConnections[0] with method SetConnection.

For explample:

rpt.DataSourceConnections[0].SetConnection(server, connection.CatalogName, connection.UserId, connection.Password);

kind regards

[edit]you should do this before you send the ReportDocument to CrystalReportViewer. Wink | ;-)

[/edit]

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