Re: can i get a 256 colors bitmap from DC directly ? - C# Discussion Boards

A managed DirectDraw / DirectX question

20-Apr-04 4:34

This is a simple problem. You treat each tab page as a separate class and add them to your TabControl. Expose what properties you need to from each tab page so that the TabControl can access them. A better OO design is to pass each tab page an object (such as a DataSet or whatever is appropriate so that each tab page can assign its own properties to its controls), which is best done by deriving from another base class that derives from TabPage. You need to create a good OO design.

Microsoft MVP, Visual C#
My Articles

yoaz19-Apr-04 21:32

Re: A managed DirectDraw / DirectX question

19-Apr-04 21:32

I've been porting code to C# while using Managed DirectX 9.0b. To access memory surfaces directly i used the Surface.Lock() method, which should return an Array, but returns a byte[,]. Annoyingly, the size of this array is the size of the surface in pixels, not in bytes. E.g. working with a 100X100 pixels surface with 16bits per pixel, the method returns a byte[100,100] (half the size). Using the array position as a pointer, and navigating it manualy using SurfaceDescription.Pitch didn't help either. If you had the patience to read this, read the code:

<br />
int stride = back.SurfaceDescription.Pitch;<br />
byte[,] barr = back.Lock  (Microsoft.DirectX.DirectDraw.LockFlags.SurfaceMemoryPointer );<br />
unsafe<br />
{<br />
  fixed (byte* pbdata = barr)<br />
  {<br />
    for (int j=0; j<100; j++)<br />
    {<br />
	for (int i=0; i<100; i++)<br />
	{<br />
	  *(pbdata+j*stride+2*i+1) = 0xF8;<br />
	}<br />
    }<br />
  }<br />
}<br />
back.Unlock(barr);<br />

this should paint my surface red, but it only paints half of it red.
What am I doing wrong?

Jeremy Kimball20-Apr-04 6:42

Jeremy Kimball

20-Apr-04 6:42

There used to be a bug regarding this that didn't actually lock all of the surface memory. Not sure if they've fixed it or not...

ok, that said, the Pitch property is the distance *in bytes* to the next line of the raster. So one "line" in the raster is actually Pitch bytes long. Hence, one pixel is (Pitch/width) bytes long. Methinks you're addressing the wrong chunk of memory as a result.

Jeremy Kimball

magnae clunes mihi placent, nec possum de hac re mentiri.
(Large buttocks are pleasing to me, nor am I able to lie concerning this matter)

Re: A managed DirectDraw / DirectX question

yoaz20-Apr-04 8:15

can i get a 256 colors bitmap from DC directly ?

20-Apr-04 8:15

Thanks, u'r absolutely right about the pitch. sorry that my code is ugly that way (the "j" index came before the "i" somehow). but i think i've tried what you've suggested:

<br />
for (int line_no=0; line_no<100; line_no++)<br />
    for (int column_no=0; column_no<100; column_no++)<br />
       *(pbdata+line_no*Pitch+2*column_no+1) = 0xF8;<br />

Do I understand what you mean, or am i missing something?
You say the bug is not locking the whole surface memory? in desperation i've tried to access bytes seemingly outside my surface (like: line_no = 120); to my surprise nothing crashed (as if i've accessed something legal), but the app seemed to be in a deadlock (so maybe it was not locked)

fu019-Apr-04 21:04

fu0

19-Apr-04 21:04

this is my screen capture code:

Bitmap bmp = new Bitmap(800,600);
public static Bitmap GetDesktopImage()
{
IntPtr hBitmap;
IntPtr hDC = GetDC（GetDesktopWindow());
IntPtr hMemDC = CreateCompatibleDC(hDC);
hBitmap = CreateCompatibleBitmap(hDC, size.cx, size.cy);

IntPtr hOld = (IntPtr) SelectObject(hMemDC, hBitmap);
BitBlt(hMemDC, 0, 0,size.cx,size.cy, hDC, 0,SRCCOPY);
SelectObject(hMemDC, hOld);
DeleteDC(hMemDC);
ReleaseDC(GetDesktopWindow(), hDC);

bmp = System.Drawing.Image.FromHbitmap(hBitmap);//<-here
DeleteObject(hBitmap);
GC.Collect();
return bmp;
}
at the arrow place,get a bitmap instance. i think the bitmap is true color depth.
Here is my question:
1.After BitBlt method, can i get a 256 color bitmap instance directly instead of a true color bitmap ?
2.if i have to get a true color bitmap, How to convert it into a 256/16/2 color bitmap quickly ?

Re: can i get a 256 colors bitmap from DC directly ?

Heath Stewart20-Apr-04 4:47

Re: can i get a 256 colors bitmap from DC directly ?

20-Apr-04 4:47

First, don't assume the desktop is 800x600. Use either SystemInformation.VirtualScreen or Screen.WorkingArea to get the Rectangle to use to size the Bitmap.

Second, you can create a 256-color bitmap by using the Bitmap.Bitmap(int, int, PixelFormat) constructor. Then create a new Graphics object for that bitmap and use GetHdc to get the DC which you could paint into. Make sure you call ReleaseHdc and then dispose your Graphics object, but do not call GC.Collect - just call Graphics.Dispose on anything you create. Calling GC.Collect can be very expensive and - if you dispose things correctly (in order to free native resources, which GC.Collect won't do) - is unnecessary.

Microsoft MVP, Visual C#
My Articles

yoaz20-Apr-04 21:24

Re: can i get a 256 colors bitmap from DC directly ?

20-Apr-04 21:24

This is a good idea, but it's not that simple if you're looking for a 256 colors bitmap.
You said:
Heath Stewart wrote:
Second, you can create a 256-color bitmap by using the Bitmap.Bitmap(int, int, PixelFormat) constructor. Then create a new Graphics object for that bitmap
But in such a bmp the colors are indexed, so that a code like:

<br />
dest_bmp = new Bitmap(width, height, PixelFormat.Format8bppIndexed);<br />
g = Graphics.FromImage(dest_bmp);

throws an exception with message:
<A Graphics object cannot be created from an image that has an indexed pixel format.>

Heath Stewart21-Apr-04 3:09

Re: can i get a 256 colors bitmap from DC directly ?

21-Apr-04 3:09

Another idea, then, would be to save the true color bitmap to a MemoryStream using a 256-color format like ImageFormat.Gif, then either return that Bitmap or create a new one by reading that stream back in using the overloaded constructor (I'm not sure if when you save it the Bitmap is actually changed - just really never tried it).

Microsoft MVP, Visual C#
My Articles

yoaz21-Apr-04 5:26

Re: can i get a 256 colors bitmap from DC directly ?

21-Apr-04 5:26

cool. this works, something like:

<br />
public Bitmap ConvertTo256Bmp(Bitmap source_bmp)<br />
{<br />
	if (source_bmp == null)<br />
        return null;<br />
	System.IO.Stream bmpStream = new System.IO.MemoryStream();<br />
	Bitmap dest_bmp = null; <br />
	try<br />
	{<br />
		source_bmp.Save(bmpStream,<br />
			System.Drawing.Imaging.ImageFormat.Gif);<br />
		dest_bmp = new Bitmap(bmpStream);<br />
	}<br />
	catch(Exception e)<br />
	{<br />
		Console.WriteLine(e.Message);<br />
		return null;<br />
	}<br />
	return dest_bmp;<br />
}<br />

this returns a bmp with Format8bppIndexed pixel format.
only thing is, the resulting bmp, when written to disk, is much larger than the original. But that's somebody else problem ? Wink | ;)

fu024-Apr-04 15:38

fu0

24-Apr-04 15:38

thanks for your suggestion. i can learn lot from your discussion.

help convert a line of code

User 96257819-Apr-04 19:41

User 962578

19-Apr-04 19:41

Can some one help me out with this C++ line of code, im trying to convert it to C#, im lost on the ** ? i look on the SDK and nothing

HRESULT CreateSession([out,retval] IMediaStatusSession** MediaStatusSession);

Parameters
MediaStatusSession

[out] Address of a variable that receives the IMediaStatusSession interface pointer.

modified 16-May-21 21:01pm.

Mazdak19-Apr-04 19:54

Mazdak

19-Apr-04 19:54

If I undestand it correctly , for [out] , you should use ref in C#.

Mazy

"I think that only daring speculation can lead us further and not accumulation of facts." - Albert Einstein

Roman Rodov20-Apr-04 2:54

Roman Rodov

20-Apr-04 2:54

Furthermore you also need to define the IMediaStatusSession interface in you code. If this is a standalone method from a static DLL. But something tells me this line of code is from an IDL declaration of a COM object, in that case you just create a Runtime Callable Wrapper (RCW) with tlbimp and it will take care of converting all you interfaces and methods for you.

User 96257820-Apr-04 9:53

User 962578

20-Apr-04 9:53

I tired TlBimp but i "ehmediastatus.idl is not a valid type library" Below is whats in the ehmediastatus.idl from microsoft. So i been trying to convert this idl in C#. IS there something im missing or doing wrong when using TlBimp?

// Properties in mediastatusproperty tuples represent new state information. The driver will receive a
// vector (MEDIASTATUSPROPARRAY) of MEDIASTATUSPROPERTY tuples. The driver needs to examine the property
// vector as a whole and decide what display changes are needed in order to present the new state on the
// annunciator display. The driver needs to decide what old information should be invalidated (for
// instance, turning off the FF indicator when REW is turned on. The driver has a lot of freedom to
// determine decay-time for OSDs and when to hide, flash, brighten, or otherwise highlight information.
// No display will have all these fields. They're laid out in this detail so that drivers can make intelligent
// decisions about what to display and how. Some status (like power, hd activity, IR activity, etc)
// are purposely omitted here. These really need to be driven directly via hardware interconnect.
typedef enum MEDIASTATUSPROPERTYTAG {
MSPROPTAG_Unknown = 0,

// These are of type VT_I4, but the value is that of another property. These properties
// can be used to modify the display of an annunciator element

// States and actions
MSPROPTAG_Mute = 0x1000,
MSPROPTAG_Play,
MSPROPTAG_Pause,
MSPROPTAG_Stop,
MSPROPTAG_Shuffle,
MSPROPTAG_RepeatSet,

MSPROPTAG_Recording,
MSPROPTAG_Rewind1,
MSPROPTAG_Rewind2,
MSPROPTAG_Rewind3,
MSPROPTAG_FF1,
MSPROPTAG_FF2,
MSPROPTAG_FF3,

MSPROPTAG_Next,
MSPROPTAG_Prev,

MSPROPTAG_Error,
MSPROPTAG_Ejecting,

// Media types
MSPROPTAG_MediaTypes = 0x2000,
MSPROPTAG_DVD,
MSPROPTAG_CD,
MSPROPTAG_PVR,
MSPROPTAG_StreamingContentAudio,
MSPROPTAG_StreamingContentVideo,
MSPROPTAG_TVTuner,

// Titles, numbers, strings, progress values and times
MSPROPTAG_MediaTime, // for the full CD or DVD

// These apply to tracks and chapters
MSPROPTAG_TrackNumber, // cd track, dvd chapter, tv channel
MSPROPTAG_TotalTracks,
MSPROPTAG_TrackDuration,
MSPROPTAG_TrackTime,
MSPROPTAG_TitleNumber,

MSPROPTAG_Volume, // in dB

MSPROPTAG_FS_Home,
MSPROPTAG_FS_TV,
MSPROPTAG_FS_DVD,
MSPROPTAG_FS_Guide,
MSPROPTAG_FS_Music,
MSPROPTAG_FS_Photos,
MSPROPTAG_FS_Videos,
MSPROPTAG_FS_RecordedShows,
MSPROPTAG_FS_Unknown,

MSPROPTAG_MediaName,
MSPROPTAG_ArtistName,
MSPROPTAG_TrackName,

MSPROPTAG_Photos,
MSPROPTAG_CurrentPicture,
MSPROPTAG_TransitionTime,

MSPROPTAG_GuideLoaded,

MSPROPTAG_SlowMotion1,
MSPROPTAG_SlowMotion2,
MSPROPTAG_SlowMotion3,
MSPROPTAG_NextFrame,
MSPROPTAG_PrevFrame,

MSPROPTAG_Radio,
MSPROPTAG_RadioFrequency,
MSPROPTAG_FS_Radio,

MSPROPTAG_Visualization, // an audio visualization is showing

MSPROPTAG_PhoneCall, // set when the phone is ringing
MSPROPTAG_CallingPartyNumber, // phone number of calling party
MSPROPTAG_CallingPartyName, // name of calling party

MSPROPTAG_ParentalAdvisoryRating, // a string such as "TV-G"
MSPROPTAG_RequestForTuner, // to broadcast that we need the tuner

// properties injected by the MSAS only - applications may not use these
MSPROPTAG_MSASPrivateTags = 0xf000,
MSPROPTAG_Application, // The name of the sourcing application
} MEDIASTATUSPROPERTYTAG;

typedef SAFEARRAY(MEDIASTATUSPROPERTYTAG) MEDIASTATUSTAGARRAY;
typedef SAFEARRAY(VARIANT) MEDIASTATUSPROPARRAY;

[
object,
uuid(A70D81F2-C9D2-4053-AF0E-CDEA39BDD1AD),
dual,
helpstring("IMediaStatusSession Interface"),
pointer_default(unique)
]
interface IMediaStatusSession : IDispatch
{
[id(1), helpstring("method MediaStatusChange")] HRESULT MediaStatusChange([in] MEDIASTATUSTAGARRAY Tags, [in] MEDIASTATUSPROPARRAY Properties);
[id(2), helpstring("method Close")] HRESULT Close();
};

[
object,
uuid(075FC453-F236-41DA-B90D-9FBB8BBDC1C5),
dual,
helpstring("IMediaStatusAggregator Interface"),
pointer_default(unique)
]
interface IMediaStatusAggregator : IDispatch
{
[id(1), helpstring("method CreateMediaStatusSession")] HRESULT CreateMediaStatusSession([in] BSTR ApplicationName, [in] BSTR WindowsSession, [out,retval] IMediaStatusSession** MediaStatusSession);
};

/*
* Media status sinks (the dll's that drive displays) must implement this interface. This interface is to be implemented on
* a co-class that is a member of the CATID_MediaStatusSink {fcb0c2a3-9747-4c95-9d02-820afedef13f} category.
* At startup, the media status aggregator will co-create all sink classes exposing this category id and will send updates to those
* sinks based on their windows session affinity.
*/
[
object,
uuid(075FC453-F236-41DA-B90D-9FBB8BBDC101),
dual,
helpstring("IMediaStatusSink Interface"),
pointer_default(unique)
]
interface IMediaStatusSink : IDispatch
{
[id(1)] HRESULT Initialize();
[id(2)] HRESULT CreateSession([out,retval] IMediaStatusSession** MediaStatusSession);
};

modified 16-May-21 21:01pm.

Roman Rodov20-Apr-04 14:52

Roman Rodov

20-Apr-04 14:52

Grrrr... If you read the documentation on TlbImp, you will note that it works on Type Libraries (DLLs, TLBs) and NOT the Interface Definition Language (plain text files). Did a search MSDN and Goodle for these intrerface names and there is basically NO mention of these on the internet, because neither MSDN nor GOOGLE have come up with anything.... What IS this stuff?

User 96257820-Apr-04 15:38

User 962578

20-Apr-04 15:38

My fault, i forgot about that and it was the first thing to come to my mind tLbimp the IDL. I look at the sdk and im creating a wrapper manually since the IDL didnt come with a Dll or tlb.

The code is for Microsoft Media Center. Its the Media State Aggregation Service, it lets user set up an PC case LCD display to show info about a current playing media, or an software to display info whatever i code it for.

I dont know much about C++, in class we never got this far, but can i just compile the IDL with a c++ compiler ( i need to find one)? if not i just continue creating a wrapper manually im almost done.

modified 16-May-21 21:01pm.

Webconfig question

dabuskol19-Apr-04 19:17

dabuskol

19-Apr-04 19:17

Hi Guys,

I just want to ask for suggestion regarding webcofig file. I declare my connection string in webconfig file so that all aspx can use the same connection under one project. (dynamic) rather than using the SqlConnection control from toolbox.
WEBCONFIG:
<add key="UserConnection" value="Data Source=localhost;server=os01;Initial Catalog=personnel ;User Id=person;password='per123'">

Question:
I'm using two server one for development and one for production. When I develop or maintain system I used of course the development which is named "os01".Is there anyway possible under webconfig file that when I transfer my project on our production machine which is named "os02" my webconfig file connection string will will detect that he is already using the production machine, from "os01"
it will become "os02" I don't have to change my webcofig file "CONNECTION STRING" everytime I change a server name.

I appreciate whatever ideas you will give, you will not only enlighten me but also others who will read this thread.

Mazdak19-Apr-04 19:57

Mazdak

19-Apr-04 19:57

Is that so hard before you compile your setup project just click some keys and change 1 to 2?

Mazy

"I think that only daring speculation can lead us further and not accumulation of facts." - Albert Einstein

dabuskol19-Apr-04 21:40

dabuskol

19-Apr-04 21:40

Hi,

Actually it's only a blink of an eye. I'm just asking for suggestion to be more dynamic. I'm maintaining and dveloping multiple systems at the same time specially if there are urgent matters.
If you're not multi tasking then your answer is acceptable.

cheers
/dabsukol

Mazdak19-Apr-04 21:55

Mazdak

19-Apr-04 21:55

Ok , one way which come to my mind is set two tag for it , when you are at debug time read it and when you use relaese setting for your project(which means its user machine) for your project read other tag. If its not clear just let me know and I explain more with details.

Mazy

"I think that only daring speculation can lead us further and not accumulation of facts." - Albert Einstein

Heath Stewart20-Apr-04 5:09