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Hello,
how it is possible to register and then get the message WM_DWMWINDOWMAXIMIZEDCHANGE?
On http://blogs.msdn.com/greg_schechter/archive/2006/09/14/753605.aspx I have found this information:
WM_DWMWINDOWMAXIMIZEDCHANGE - windows can register to hear about when other windows have been maximized. This is useful for, for instance, the TaskBar or the SideBar which go opaque when other windows get maximized.
The following code will not detect the message WM_DWMWINDOWMAXIMIZEDCHANGE but the other messages like WM_DWMCOLORIZATIONCOLORCHANGED will be detected. (Desktop compositing is enabled and the following code is in a simple windows form created by vs2005)
private const int WM_DWMCOMPOSITIONCHANGED = 0x031E;
private const int WM_DWMNCRENDERINGCHANGED = 0x031F;
private const int WM_DWMCOLORIZATIONCOLORCHANGED = 0x0320;
private const int WM_DWMWINDOWMAXIMIZEDCHANGE = 0x0321;
protected override void WndProc(ref Message msg)
{
if (msg.Msg == WM_DWMWINDOWMAXIMIZEDCHANGE)
{
}
base.WndProc(ref msg);
}
May you have some information how register and detect this message...
Regards michi
-- modified at 6:35 Saturday 17th February, 2007
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Im trying to take every pixel in a Bitmap and save it in bye array.... Buit Im getting a n error
"Attempted to read or write protected memory. This is often an indication that other memory is corrupt"
Can any1 tell me wht wrong with this code
<br />
public static byte[] check(Bitmap b)<br />
{<br />
BitmapData bmData<br />
= b.LockBits(new Rectangle(0, 0, b.Width, b.Height), ImageLockMode.ReadOnly,PixelFormat.Format24bppRgb);<br />
int stride = bmData.Stride;<br />
byte[] bytes = new byte[stride * b.Height];<br />
System.IntPtr Scan0 = bmData.Scan0;<br />
unsafe<br />
{<br />
int a = 0;<br />
byte* p = (byte*)(void*)Scan0;<br />
int nOffset = stride - b.Width * 3;<br />
int nWidth = b.Width * 3;<br />
for (int y = 0; y < b.Height; ++y)<br />
{<br />
for (int x = 0; x < nWidth; ++x)<br />
{<br />
<br />
bytes[a] = p[0];<br />
a++;<br />
Here I got the error-> bytes[a] = p[1];<br />
a++;<br />
bytes[a] = p[2];<br />
a++;<br />
p += 3;<br />
<br />
}<br />
p += nOffset;<br />
}<br />
}<br />
b.UnlockBits(bmData);<br />
return bytes;<br />
}<br />
<br />
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Read my image processing articles. You're stepping over the scanline into the stride area.
Christian Graus - Microsoft MVP - C++
Metal Musings - Rex and my new metal blog
"I am working on a project that will convert a FORTRAN code to corresponding C++ code.I am not aware of FORTRAN syntax" ( spotted in the C++/CLI forum )
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How about using serialisation? You could even use this to store practiaclly any object into a database.
Try this:
1) Create a new windows form app
2) Add to the form 2x picture boxes, one named source, the other dest
3) Add a new button named serialise
4) Set the background image of the picturebox named source to whatever you want (for testing, do this using the designer)
5) Add a handler to the buttons click event (this normally happens automatically if you double click the button in the designer)
6) Add using System.Runtime.Serialization.Formatters.Binary; declaration to your class
7) Paste the following code:
void SerialiseClick(object sender, EventArgs e)
{
byte[] byteArray = Serialise( source.BackgroundImage );
dest.BackgroundImage = (System.Drawing.Image)Deserialise(byteArray);
}
public static byte[] Serialise( object obj )
{
System.IO.MemoryStream ms = new System.IO.MemoryStream();
BinaryFormatter bf = new BinaryFormatter();
bf.Serialize( ms, obj );
return ms.ToArray();
}
public static object Deserialise( byte[] obj )
{
System.IO.MemoryStream ms = new System.IO.MemoryStream( obj );
BinaryFormatter bf = new BinaryFormatter();
return bf.Deserialize(ms) ;
}
There is also Image.FromStream method which could be used instead and probably other ways of achieving a similar result.
Feel free to download the sample code I wrote from here: http://www.box.net/public/14kiat6na7
I love serialisation
Regards
Wayne Phipps
____________
Time is the greatest teacher... unfortunately, it kills all of its students
View my Blog
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How to drag a line from one to another point.
Exp. from (10, 40) to (80, 90).
Help.
In VS 2003.
C#
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draw it, or drag it ?
Christian Graus - Microsoft MVP - C++
Metal Musings - Rex and my new metal blog
"I am working on a project that will convert a FORTRAN code to corresponding C++ code.I am not aware of FORTRAN syntax" ( spotted in the C++/CLI forum )
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You may track the mouse movement, but this will cause you a refresh and redraw to the line every small pixels.
------------------------------
"The Soapbox has been so ..."
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Well, a friend requested an application, and I've been working on it. And it requires detecting and accessing a USB flash drive.
I looked in the article:
http://www.codeproject.com/dotnet/devicevolumemonitor.asp
I am not using it with a USB Flash Drive right now, just CDs. Well, I'm having an issue. When I insert a CD (drive D: OR E , I get this:
Volume inserted in
No drive letter. But when I eject the CD, it says:
Volume removed from D:/E:
Whichever drive I put the CD in. Could someone else try it out and try to find what's going wrong. I didn't modify the code. I simple downloaded the source code, and built it.
I'm on Windows 2000 Pro Service Pack 4, and VS .NET 2005 Pro. I also tried it on VS .NET 2003 Pro.
Thanks in Advance,
Matt U.
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Ok i have created my first quality application for windows, a Puzzle game and i am planning on giving out a test version to my friends so that any errors found can be fixed. I have added a Rich text box to the app and i want the text that is input into it saved. i know this involves databases and the book i have on C# is very unclear about anything to do with data bases. So i need to know how to create a database and how save the text to it and have it recalled when it loads i know this is alot of work but any help would be much appreciated.
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Why use DB, you may use files, easier, faster, and helpful, you may use System.IO for it, its very easy,
If you are considering files then take a look at TextWriter and TextReader classes of the IO namespace .
------------------------------
"The Soapbox has been so ..."
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i keeping getting an error message stating "Unrecognized escape sequence" when i tell it what file to read any ideas why or how to fix it?
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Use @ infront of the string like
string path = @"mtapp\mypath\";
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Hi,
I desperatelly need an answer on my probably dumb question  .
I use data bound DataGridView control and I need (on click of the button) to programmatically add row. When I use command DataGridView1.Rows.Add() I get message: "Rows cannot be programmatically added to the DataGridView's rows collection when the control is data-bound.". How can I trigger event that causes to create new row?
Thanks,
Aleks
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Add a row to the datatable that is the source, and remove it later.
------------------------------
"The Soapbox has been so ..."
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So simple and so smart. Thanks a lot.
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I am currently trying to build a serial monitoring program.
I am planning on using several ChildMDI forms to hold data grids with decoded serial data. I built an event driven serial driver, and when a packet is received, an event is fired. From that eventhandler, I am trying to call methods within the ChildMDI forms to update their data. When the event fires, everything is executed, except the calls to the ChildMDI forms. Its as if the calls are never made (I have tried one of the methods I wrote, and just using .Close() to no avail). I have verified the methods work by inserting a test button and have gotten the Child forms to respond to that. Is this something that just won't work, or do I need to configure it in a special way?
Thanks!
-- modified at 15:15 Friday 16th February, 2007
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I have an application that frequently modifies the values of certain strings that are attributes of some classes that I use in the application. These strings get modified once every 1-4 minutes during normal software operation. Would the StringBuilder class provide any performance enhancement over a String in this situation?
Thanks.
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Have you tried testing this yourself using the stopwatch class of the System.Diagnostics namespace (should be the correct namespace)?
Regards,
Thomas Stockwell
Programming today is a race between software engineers striving to build bigger and better idiot-proof programs, and the Universe trying to produce bigger and better idiots. So far, the Universe is winning.
Visit my homepage Oracle Studios[ ^]
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Probably not. You incur a hit at three times with a StringBuilder: initialization, ensuring capacity (internal), and calling ToString. I'm guessing you'd be calling ToString too frequently to be a real benefit.
That being said, you definitely need to test it to be sure. Start with the easiest, reasonable implementation and then if the performance is an issue then examine other alternatives.
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I personally have noticed a large difference in performance but then I wasnt building and displaying constantly. I was doing more batch text processing.
Cleako
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Hi,
StringBuilder will show much better performance than string when you need to calculate complex string expressions as in:
string s="the alphabet consists of ";
foreach (char c in "abc...z") s=s+c;
Inside the loop each s=s+c; will create a new string, copy the existing characters and append
one (that is a quadratic operation: when the number of iterations doubles, the cost
will quadruple).
With StringBuilder nothing gets copied as long as the StringBuilder's capacity is
sufficient. So I would say if there are fewer than 3 to 5 operations, string will be faster;
in my example StringBuilder will win hands down; and yes it helps to give it adequate
initial capacity.
Luc Pattyn
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Just to echo the others in the forum, you really need to do testing to be sure. Hook up a performance counter to figure out if it's bottlenecking your application.
That being said, it sounds like your code isn't doing enough work to warrant using StringBuilder objects. Are you modifying only a handful of strings every 1 - 4 minutes? If so, is it worth it to you to optimize away a few milliseconds out of every few minutes?
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I am trying to compress a jpg file in the same manner that you would set the quality factor in an image processing package e.g.
Open image1.jpg
Set quality factor to 50
Save as image2.jpg
This is to reduce the size of the jpg files in my application.
Does anyone know if there are .NET libraries for this or any good commercial toolkits.
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<br />
System.Drawing.Imaging.EncoderParameters encParams = new System.Drawing.Imaging.EncoderParameters();<br />
encParams.Param[0] = new System.Drawing.Imaging.EncoderParameter(System.Drawing.Imaging.Encoder.Quality, Quality);<br />
MemoryStream ms = new MemoryStream();<br />
_reformattedImage.Save(ms, System.Drawing.Imaging.ImageCodecInfo.GetImageEncoders()[1], encParams);<br />
_reformattedImage = Image.FromStream(ms);
That's raw code straight out of an app i've got infront of me it's got the quality methods you'll need though. Quality is the parameter from 1 to 100 that sets the quality level
Things like Bitmap should have load and save methods on them (you can load jpegs into bitmap objects).
HTH
Russ
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Thanks Russell. For completeness my final solution was:
private ImageCodecInfo GetEncoderInfo(String mimeType)<br />
{<br />
int j;<br />
ImageCodecInfo[] encoders;<br />
encoders = ImageCodecInfo.GetImageEncoders();<br />
for(j = 0; j < encoders.Length; ++j)<br />
{<br />
if(encoders[j].MimeType == mimeType)<br />
return encoders[j];<br />
} <br />
return null;<br />
}<br />
<br />
Image image = Image.FromFile(sourceFile);<br />
<br />
string mimeType = "image/jpeg";<br />
ImageCodecInfo codecInfo = GetEncoderInfo(mimeType);<br />
if (codecInfo == null)<br />
raise error;<br />
<br />
Encoder qualityEncoder = Encoder.Quality;<br />
EncoderParameter ratio = new EncoderParameter(qualityEncoder, 40L);<br />
EncoderParameters encoderParams = new EncoderParameters(1);<br />
encoderParams.Param[0] = ratio;<br />
<br />
image.Save(destFile, codecInfo, encoderParams);<br />
image.Dispose();<br />
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