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Hi there,
I am new to the graphics section of C#.
I wanted to change the monochrome bitmap to byte array and send the pixel data to the serial thermal printer.
When i convert the bitmap to byte array, the first two byte i get is 13780 instead of 19778 (representation of BM as per bitmap specs). I used the following code as reference:
ImageData = ConvertImageToByteArray(bmp,System.Drawing.Imaging.ImageFormat.Png);
private static byte[] ConvertImageToByteArray(System.Drawing.Image imageToConvert,ImageFormat formatOfImage)
{
byte[] Ret;
using (MemoryStream ms = new MemoryStream())
{
imageToConvert.Save(ms,formatOfImage);
Ret = ms.ToArray();
}
return Ret;
}
if i call the above function as below
ImageData = ConvertImageToByteArray(bmp,System.Drawing.Imaging.ImageFormat.<b>Bmp</b>);
then all the byteArray is filled with 0;
What am i doing wrong? Or is there any other approach for doing this? Any solution and suggestion will be appreciated.
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MacMohan wrote: the first two byte i get is 13780
How do you calculate that value?
---
b { font-weight: normal; }
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I display the byteArray in the textbox.
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Yes, but how do you turn the two first bytes into that value?
---
b { font-weight: normal; }
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Hi,
Try using this code to copy the bytes form a bitmap to a byte array:
<br />
public byte Copy(Bitmap img)<br />
{<br />
BitmapData imgData = img.LockBits(new Rectangle(0, 0, img.Width, img.Height), ImageLockMode.ReadWrite, img.PixelFormat);<br />
IntPtr scan = imgData.Scan0;<br />
byte[] buffer = null;<br />
if (img.PixelFormat == PixelFormat.Format24bppRgb)<br />
buffer = new byte[img.Width * (img.Height / 3) * 3];<br />
else<br />
buffer = new byte[img.Width * (img.Height / 3) * 4];<br />
Marshal.Copy(scan, buffer, 0, buffer.Length);<br />
img.UnlockBits(imgData);<br />
return buffer;<br />
}<br />
<br />
Hope it helps<br />
Do your best to be the best
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I am looking for a solution for intercepting or redirecting the STDOUT to a stream or in the end to a TextControl. For redirecting STDOUT of another process or Console.Out I found a lot of solutions, but that wasn't working with my problem.
In my scenario the C# application calls some functionality from an unmanaged DLL. The unmanaged function produce normally a lot of console output. My idea was to hide the console and redirect the STDOUT and perhaps the STDERR to a StringWriter and further to a multi line TextControl.
Setting a StringWriter via Console.SetOut only works for Console calls, but not for the unmanaged stuff from the DLLs.
After some more investigation I found the Win32 console functions likes SetStdHandler. Currently it seems to be the solution for my problem. But now I do not know, how to get a "FileHandle" from a StringWriter Stream and I do not want to use a FileStream for it.
Does anybody has an idea or knows another way of redirecting the STDOUT to a StringWriter or a TextControl?
Thanks in advance,
Lars
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Have you looked at the System.Diagnostic.Process class? It has some methods on it to redirect standard output.
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I believe System.Diagnostic.Process only lets you redirect the STDOUT of a child process. His parent process (C#) is running unmanaged code that writes to the console but not via Console.Out.
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You are right on this. With System.Diagnostic.Process you can only read StandardError and StandardOutput and write to StandardInput of the child process, which System.Diagnostic.Process has started.
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If you use C++/CLI, you could write wrapper code. I did not write wrapper code below. However, it is just a demo on how you can integrate manage and unmanage code in C++/CLI
#pragma unmanaged
#include <iostream>
#include <sstream>
#include <string>
class Foo
{
public:
Foo()
{
std::wcout.rdbuf(ostr.rdbuf());
}
void UnmanagedOut()
{
std::wcout << L"George";
}
std::wstring Redirect()
{
return ostr.str().c_str();
}
private:
std::wostringstream ostr;
};
#pragma managed
using namespace System;
int main(array<System::String ^> ^args)
{
Foo foo;
foo.UnmanagedOut();
String ^out = gcnew String(foo.Redirect().c_str());
Console::WriteLine(out);
return 0;
}
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This looks like a nice idea, but this approach will only redirect cout or wcout stream of C++ into a string. But probably anything written via printf to STDOUT and STDERR won't be intercepted.
Another point could be that the unmanged code resides within a DLL, so using this approach won't probably help anyway, because the cout stream is already linked to the underlying API calls. And changing the DLL is a no-go. That makes the problem so difficult.
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Yes, I haven't verified that this will work and I know that it won't capture printf output. However, if you can get this to work then cerr STDERR and printf STDOUT/STDERR would be easy to redirect via a C++ wrapper.
The C++/CLI wrapper assembly will be compiled and linked using your 3rd party unmanage library. Thus, it should have direct access to unmanaged STDOUT/STDERR for redirection. So, instead of get the managed code to redirect, you let the unmnanaged code in the wrapper do the redirecting. Nevertheless, I don't have experience of this working. Also, I heard mention of redirecting STDOUT/STDERR to a pipe in my Google Searches.
Also, I found this code (I don't know how useful it is) doing a Google search:
http://www.123aspx.com/rotor/RotorSrc.aspx?rot=40353[^]
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I just want to confirm that I did get the cout STDOUT to redirect to a string buffer. I created a DLL that outputs to the console via wcout. Then, I created a C++/CLI wrapper of that code in a managed assembly. I referenced the C++/CLI managed assembly in a C# application which received the redirected output into a System.String object.
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I am populating a gridview table with an asp:SqlDataSource and get the data in my codebehind this way:
int ID = (int)ListEmps.SelectedDataKey.Values["EmpID"];
int UnitNum = (int)ListEmps.SelectedDataKey.Values["UnitNum"];
string Unit = ListEmps.SelectedDataKey.Values["UnitType"].ToString();
string FName = ListEmps.SelectedRow.Cells[3].Text;
string LName = ListEmps.SelectedRow.Cells[4].Text;
And I know it retrieves the data properly. I need that data to be used in another .aspx/.aspx.cs file to define some asp:labels. I understand how to do this with SQL using Request.QueryString[], but I'm not sure how to do it with the GridView.
Thanks!!
K. Garl
Intranet Web Coordinator
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kgarl wrote: I understand how to do this with SQL using Request.QueryString[]
and how do you use a QueryString in SQL?
You need to use the same data on two or more forms? Get it from the same source, such as a business or data layer object.
only two letters away from being an asset
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Nevermind. I figured out how to do it last night. Thanks.
K. Garl
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I am wondering about MS Power Point. How does power point keep track of all its slides on the left side, where does it stores all the slides. Does it rewrite everything again on the left side slide when we open a power point file. Can some body tell me in details. Thanks
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netJP12L wrote: where does it stores all the slides
RAM
netJP12L wrote: Does it rewrite everything again on the left side slide when we open a power point file.
Well, when you open a file, it has new files in memory, yes.
netJP12L wrote: Can some body tell me in details. Thanks
I doubt that any of the powerpoint team are in right now. What are you asking for ? do you want to write something similar in C# ?
Christian Graus - C++ MVP
'Why don't we jump on a fad that hasn't already been widely discredited ?' - Dilbert
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Christian Graus wrote: I doubt that any of the powerpoint team are in right now.
Did they call in sick? 
Some people have a memory and an attention span, you should try them out one day. - Jeremy Falcon
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Christian Graus wrote: I doubt that any of the powerpoint team are in right now
That should be on their answering machine
Arthur Dent - "That would explain it. All my life I've had this strange feeling that there's something big and sinister going on in the world."
Slartibartfast - "No. That's perfectly normal paranoia. Everybody in the universe gets that."
Deja View - the feeling that you've seen this post before.
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hi
i want to write Client/Server Programming database with vc#2005 & sql2005 or 2000, but how to connect to sqlserver from network and how to insert,Update,Delete transaction in my database on the network??
Please get me an article or full description on this topic.
thanks..
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hdv212 wrote: i want to write Client/Server Programming database with vc#2005 & sql2005 or 2000, but how to connect to sqlserver from network and how to insert,Update,Delete transaction in my database on the network??
Please get me an article or full description on this topic.
Again, your question is pretty vague.
You can use the SqlConnnection class and related objects to connect to an SQLServer via the network. The connection string determines which server to connect to. This[^] covers the standard ways of connecting to the various server configurations.
As for the Insert/Update/Delete, I use stored-procedures that are executed from SqlCommand objects.
The Microsoft Enterprise Library Data Application block[^] is my preferred method of writing DB code.
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Add the server to Visual Studio's server list, and drag and drop.
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hi
does anyone say to me How to acess Sql Server 2005 Reporting Services's Fields and how to get/set it's Values ?
i went many ways for this work but i don't get true results.
Please write a code that i can access to reporting srvice and get/set its values.
thanks
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hdv212 wrote: does anyone say to me How to acess Sql Server 2005 Reporting Services's Fields and how to get/set it's Values ?
i went many ways for this work but i don't get true results.
Please write a code that i can access to reporting srvice and get/set its values.
Your question is a little vague.
Reporting services is usually programmed via it's web-service.
See here[^] for more details, including examples.
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