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Heath Stewart17-May-04 7:21

17-May-04 7:21

A much more efficient way is to call LockBits and use an unsafe context to manipulate and read pixels, then call UnlockBits. See Christian Graus's article, Image Processing for Dummies with C# and GDI+ Part 1 - Per Pixel Filters[^], for more information.

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Potential Field Algorithms

sodium17-May-04 6:45

sodium

17-May-04 6:45

Hi all

I have currently learning to program in C#. I am inspired by the A* path-finding C# algorithms written by Eric Marchesin.

I like to seek help on the implementation of Potential Field Method for robot navigation.

Can anyone show how the complex objects( such as goal, robot, multi-shaped obstacles) can be created systematically ? I am really at a lost.

Other challenges include solving local minima problem and intelligent navigation.

Anyone who has the expertise.Please your help is very much appreciated.

Re: Potential Field Algorithms

Dave Kreskowiak17-May-04 7:14

Dave Kreskowiak

17-May-04 7:14

sodium wrote:
Can anyone show how the complex objects( such as goal, robot, multi-shaped obstacles) can be created systematically ?

What do you mean by "systematically"?

RageInTheMachine9532
"...a pungent, gastly, stinky piece of cheese!" -- The Roaming Nome

Re: Potential Field Algorithms

sodium17-May-04 20:11

sodium

17-May-04 20:11

methodically would be a better description. Dave, are you capable ?

Re: Potential Field Algorithms

Dave Kreskowiak18-May-04 0:08

Dave Kreskowiak

18-May-04 0:08

Nope. Never touched Navigation algorithms...

RageInTheMachine9532
"...a pungent, gastly, stinky piece of cheese!" -- The Roaming Nome

Converting xsd to csv using xslt

tunde17-May-04 6:44

tunde

17-May-04 6:44

I am having a problem with xsd convertion to csv file. The code below describes how I attempted to approach the problem. The code works but the output is not properly format.

ObjBISReports As DsReports (a type dataset)
.. after the dataset has been filled using sqldatadapter
ObjBISReports.WriteXml("C:\Tunde.xml", XmlWriteMode.IgnoreSchema)

Dim xslt As New XslTransform()
xslt.Load("F:\Alliance International\Projects\AIA Database Application\Application2\Components\GetOutStanding.xslt")

Dim doc As New XmlDocument()
doc.Load("C:\Tunde.xml")

'Create an XmlTextWriter which outputs to a file.
Dim fileName As String = "C:\tunde.csv"

Dim writer As XmlWriter = New XmlTextWriter(fileName, Nothing)

'Transform the data and send the output to the console.
xslt.Transform(doc, Nothing, writer)
writer.Close()

This is the stylesheet format:

"<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output method="text"/>

<xsl:template match="DsReports">
<xsl:apply-templates select="GetOutStandingBills"/>
</xsl:template>

<xsl:template match="GetOutStandingBills">
<xsl:for-each select="*">
<xsl:value-of select="."/>
<xsl:if test="position() != last()">
<xsl:value-of select="','"/>
</xsl:if>
</xsl:for-each>
<xsl:text>
</xsl:text>
</xsl:template>

</xsl:stylesheet>"

Please if anyone knows a much effective means of converting xsd to csv or excel could you let me know.
Thank You

Tunde Olawuwo

Re: Converting xsd to csv using xslt

Heath Stewart17-May-04 7:17

Heath Stewart

17-May-04 7:17

Notice you're using VB.NET - this belongs in the VB.NET forum. But since it really has more to do with the XSLT, the answer is simple: you must set the xsl:output method (assuming xsl is your namespace prefix for the XSL Transform namespace) so that the method attribute is just text. Then you must make sure that a new line is output after the last element in the CSV. A simple way is to output a CR-LF pair like so:

<xsl:text disable-text-escaping="yes">&#13;&#10;</xsl:text>

Microsoft MVP, Visual C#
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Re: Converting xsd to csv using xslt

tunde17-May-04 13:02

tunde

17-May-04 13:02

oops sorry for posting vb question in a C# region. Thanks I appreciate it!

Bitmaps

Saleh Alshadheli17-May-04 6:30

Saleh Alshadheli

17-May-04 6:30

How can I recognize the characters in a bitmap using c#?
(Im doning OCR prgram)

Re: Bitmaps

Dave Kreskowiak17-May-04 6:40

Dave Kreskowiak

17-May-04 6:40

You could Google for 'OCR' algorithms. There is one here[^] on CodeProject.

RageInTheMachine9532
"...a pungent, gastly, stinky piece of cheese!" -- The Roaming Nome

Why this default Directory?

Adam °Wimsatt17-May-04 5:38

Adam °Wimsatt

17-May-04 5:38

XmlTextReader reader = new XmlTextReader ("faq.xml");

Why is the default directory for this code = c:\winnt\system32? Maybe I'm missing something, but since this code is located inside of a ASP.Net Default.aspx file... shouldn't it default to the web root?

Re: Why this default Directory?

Heath Stewart17-May-04 5:57

Heath Stewart

17-May-04 5:57

No it shouldn't. It has to do with the executable path or the current working directory set by the executable.

To open a file in a virtual directory, you should use the MapPath method, which is available both on the intrinsic Server property of several objects (an instance of HttpServerUtility) or on the Page class itself:

// Inside a method of the path, for example
string path = MapPath("faq.xml");
XmlTextReader reader = null;
try
{
  reader = new XmlTextReader(path);
  // ...
}
finally
{
  if (reader != null) reader.Close();
}

Microsoft MVP, Visual C#
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Re: Why this default Directory?

Adam °Wimsatt17-May-04 6:04

Adam °Wimsatt

17-May-04 6:04

Thanks for the tip. Do you have any suggetions (websites) for a beginners guide to updating XML files in C#?

Re: Why this default Directory?

Heath Stewart17-May-04 6:19

Heath Stewart

17-May-04 6:19

As I always say - read the .NET Framework SDK. Specifically, read the topic, Exploying XML in the .NET Framework[^]. Don't forget to read the class documentation as well, specifically the members in the System.Xml[^] namespace and child namespaces.

Microsoft MVP, Visual C#
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using excel in c# problem

Russell Jones17-May-04 5:37

Russell Jones

17-May-04 5:37

I'm trying to find the top of a cell in excel.

i tried this code in vba:

something = OutputWorksheet.Range("A1","A1").Top

this works fine

the only way i've found of getting c# to do the same is:

float something = (float)Convert.ToDouble( OutputWorksheet.get_Range("A1","A1").Top.ToString())

is this really the way i have to do this cast?

Thanks

Russell

Re: using excel in c# problem

Heath Stewart17-May-04 5:54

Heath Stewart

17-May-04 5:54

Um, why convert to a Double and then cast to a Single (float)? Also, get_Range returns a Range object, from which you can get the Top and just cast that to a float like so:

Range rng = OutputWorksheet.get_Range("A1", "A1");
float top = (foat)rng.Top;

Microsoft MVP, Visual C#
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C# design question

pankajdaga17-May-04 5:01

pankajdaga

17-May-04 5:01

Hi everyone,

I have an application that should support two types of databases (SQL Server and Oracle). What I want to do is create a datalayer that will use SqlConnection or OracleConnection object depending on the database.

In C++ I would have done the following:

template<class ConnectionType>
class DataLayer
{
...
...

ConnectionType * type
}

DataLayer<SqlConnection> m_layer; // for example

How can I achieve the same result in C#?

Thanks,

Sincerely,

Pankaj

Without struggle, there is no progress

Re: C# design question

Heath Stewart17-May-04 5:10

Heath Stewart

17-May-04 5:10

You would use the provider pattern, an abstract class or interface that contains the methods you would invoke. You then use the appropriate implementation (SQL, Oracle, whatever) that you could configure in the application's .config file. We've been using this since .NET 1.0 for our smart client application.

.NET 2.0 will use the provider pattern heavily: for database access, authentication, personalization, and much, much more.

For more information, you should read a couple of recent MSDN articles:

Microsoft MVP, Visual C#
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Re: C# design question

pankajdaga17-May-04 7:32

pankajdaga

17-May-04 7:32

Thanks Heath!

Pankaj

Without struggle, there is no progress

Managing 3 applications at the same time

Diego F.17-May-04 4:55

Diego F.

17-May-04 4:55

Hi. I need 3 applications working at the same time. The first one is a
Pocket PC application, the second is a web service and the third one isn't
done yet. This third app is only to receive messages (maybe a Windows Forms
application or even an ASP.NET one...)

The question is how to send messages to the third application. It should be
the web service when the Pocket PC calls a web method. How could I do that?
Remoting? I only need to send a string, so the easier method Wink | ;-)

Regards,

Diego F.

Re: Managing 3 applications at the same time

Heath Stewart17-May-04 5:06

Heath Stewart

17-May-04 5:06

.NET Remoting is probably the easiest way. The PPC (presumably a .NET CF application) would call the web service method, which calls a remoting method on the third application. It should be tollerant that the third application might not be running, especially if this is an application that must be started by the user (like a desktop application monitor or something).

Microsoft MVP, Visual C#
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Re: Managing 3 applications at the same time

Diego F.17-May-04 5:33

Diego F.

17-May-04 5:33

OK, then I'll try with Remoting. Is there any consideration I should know using Remoting with web services or is just the same way as using Remoting between two console applications?

Regards,

Diego F.

Re: Managing 3 applications at the same time

Heath Stewart17-May-04 5:38

Heath Stewart

17-May-04 5:38

You should be mindful of the service registration type. If you use a singleton - depending how the remoting object is hosted, yours calls may be synchronous while web service methods are not. This will result in synchronous-like method calls to your web service. The lifetime of the remoting object is also a factor. Basically, there's a lot of factors that go into this. If you're not familiar with .NET Remoting, I suggestion a couple of books. I just posted these earlier today, so I'll just refer you to that post[^].

Microsoft MVP, Visual C#
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Combobox

bertcox17-May-04 4:54

bertcox

17-May-04 4:54

Hi,

I have a combobox and now i want that you can see the first item when it's filled. Now it's empty and you can type in the combobox.

Thx!

Re: Combobox

Heath Stewart17-May-04 5:04

Heath Stewart

17-May-04 5:04

You should change the DropDownStyle property to ComboBoxStyle.DropDownList. The default is DropDown and allows you type, where DropDownList doesn't. If you want the user to be able to type in new items, then you should set the SelectedIndex to 0.

Microsoft MVP, Visual C#
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