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try as following:
String ^str="9.99";
System::Single d=Single::Parse(str);
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This won't help, it will still have the accuracy problem.
MVP 2010 - are they mad?
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The following code is from a Visual C++ app to copy a file from one directory to another. It has been simplified, so I can get it working, from the objective where button and textbox controls will populate the String^ variables. I think its pretty clear what the code is trying to do, however I can't get it to work. I would appreciate any help in fixing it, any suggestions of a better approach if this one seems wrong or even some code/advice on how to trap and read any errorcodes that the CopyFile function is trowing instead of the simple messagebox I'm using.
Thanks in advance,
<br />
String^ source = "C:\Temp\Firefox.pcv";<br />
String^ dest = "E:\Test\Firefox.pcv";<br />
char* file1 = (char*)(Marshal::StringToHGlobalAnsi(source + "\0")).ToPointer();<br />
char* file2 = (char*)(Marshal::StringToHGlobalAnsi(dest + "\0")).ToPointer();<br />
<br />
if(CopyFile((LPCTSTR)file1, (LPCTSTR)file2, TRUE) == 0){<br />
MessageBox::Show("ERROR");<br />
}else{<br />
MessageBox::Show("OKAY");<br />
}<br />
<br />
Marshal::FreeHGlobal(IntPtr((void*)file1));<br />
Marshal::FreeHGlobal(IntPtr((void*)file2));<br />
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Because you are using managed code why don't you just use:
File::Copy( path, path2 );
Here is the MSDN article.
Greetings
Covean
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"I can't get it to work" isn't real helpful to us.
Did you check the error code?
Also, for what it's worth, your casts of char* to LPCTSTR in
the CopyFile() call are wrong.
I always recommend, if you're going to use a cast,
ask yourself why you need a cast. Because it won't
compile without it? If so, why?
Then if you do really need the cast, use the right types.
Mark Salsbery
Microsoft MVP - Visual C++
![Java | [Coffee]](https://codeproject.global.ssl.fastly.net/script/Forums/Images/coffee.gif)
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code as following,
String^ source = "C:\\Temp\\Firefox.pcv";
String^ dest = "E:\\Test\\Firefox.pcv";
System::IO::File::Copy(source,dest);
using the clr base as much as better,it's simple and clear.
the system::io::file is a static class .
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I have create application using vc++ 2005 clr form application n trying to deploy my application using package and deploy , n when I install my pc on another computer it show msgbox
"this application has failed to start because the configuration is incorect . reintaling the application may fix the problem"
I already reinstal my application n still this msgbox shown up , n I try many thins like instaling .ne framwork 2.0 and instaling all necesary vc++ 2005 distrubutable file but still o the same result
any one can help me ?? please
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Make sure you're using the right build configuration for the target platform. I've had some apps where the default Win32 coniguration gave me this error message, but compiling with the x86 config worked fine.
Dybs
The shout of progress is not "Eureka!" it's "Strange... that's not what i expected". - peterchen
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Hi
use "depends.exe" to see which .dll could not be found. Maybe you also installed one of the last security updates from Microsoft. This gives the problem that the runtime dll's (MFC, CLR) changes. you can copy depends.exe to the client you have installed your app and load your application. You should see whats going on. A really helpful tool...
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Hi
I have a simple Win32 application with one window. It implements the IAccessible interface to expose some functionality to screen readers.
If I compile it for 32-bit, everything works fine. AccExplorer32, UISpy and Narrator all recognize my interface and the data it provides.
If I compile for 64-bit, AccExplorer32 works fine, but UISpy and Narrator don't. The difference is that AccExplorer32 is native code and UISpy/Narrator are managed. BTW, I believe both UISpy and Narrator are 64-bit applications.
They successfully request my IAccessible object, but after that only QueryInterface, AddRef and Release are getting called. None of the IAccessible or IDispatch methods are being accessed.
So my current theory is that there is some trick to getting 64-bit COM interfaces accessed by managed code. Am I on the right track? What can I do to fix this problem or at least understand what is happening?
Thanks
Ivo
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I'm trying to take existing Bitmaps images in memory and save (or copy)the bits data to an HGLOBAL. Is this possible using .NET classes? The Bitmap images in memory use the System::Drawing::Bitmap classes not the GDI+ version. I can use some of the GDI+ methods if needed but wanted to state the Images originate from the non GDI+ kind.
I've tried the LockBits function but the data that is extracted does not appear proper when viewed in the debugger. I think it's missing the BITMAPINFOHEADER data.
Has anyone done anything like this? It's sort of a reverse of creating an image starting from HGLOBAL and going through the steps to the resulting image.
modified on Tuesday, January 19, 2010 4:28 PM
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Actually the lockbits and it's methods give you the opportunity to get the raw information of the bitmap stored sequentially from position Scan0, each line length have a certain Stride dimension and the information is stored according to PixelFormat.
http://www.bobpowell.net/lockingbits.htm[^]
Usually this method is used for fast access to the bitmap so you can easyle manipulate the data within it or copy the data to other portion of memory (marshall copy).
If you need also the header you can easily create it by yourself...see http://en.wikipedia.org/wiki/BMP_file_format[^]
modified on Wednesday, January 20, 2010 3:07 AM
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Thanks for replying.
The problem with this is that I don't need any access to the bit's except to make a reference to it for calling a Save method. There seems to me to be more utility in the GDI+ functions than there are in the .NET classes. Since I am starting out with a .NET image, I would like to stay with the appropriate classes. I know the Global functions are deprecated, but the means of which the images are acquired, are with legacy code in ActiveX controls so Global functions are appropriate. If need be, I'll use GDI+, but not sure how to get there.
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maybe i don't get the problem but this is waht i understand from your explanation
you want to have a pointer to a memory segment which contains bmp header + bmp data row right?
if yes you can do so
1) create a pointer of dimension 54+RowSize*Height*3 bytes (a classic 24 bit rgb)
example:
array<byte> ^memoryData=gcnew array<Byte>(54 + RowSize*Height*3);
pin_ptr<unsigned char>tmpP1 = &memoryData[0];
unsigned char *np1 = tmpP1;
2) create you personal 54 byte header (http://en.wikipedia.org/wiki/BMP_file_format[^]) or find googling someone that have already done it
3) copy the header in the first part of the memory...use marshall copy and copy to the location memoryData[0]
4) lockbit the image and copy the raw information using marshall copy and copy to the location memoryData[54]
the trick is done if i have understand your real problem
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I guess I failed to explain better.
I have one HGLOBAL. This is used to create an image of type System::Drawing::Bitmap.
HGLOBAL hdl = GloabalAlloc(BitmapImageSize);
PBITMMAPINFOHEADER bmih = (PBITMAPINFOHEADER)GlobalLock(hdl);
LPDWORD ImgBits = (LPDWORD)(bmih + sizeof(BITMAPINFOHEADER));
....
....
....
StretchDIBits()......
That gives me an image from an HGLOBAL
If I had an image already in memory, from some other means (loaded from file maybe), I want to then point that image to the HGLOBAL.
Hope that was clearer
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OK thanks for that.
How then do you copy that to HGLOBAL?
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alleyes wrote: The Bitmap images in memory use the System::Drawing::Bitmap classes not the GDI+ version.
System.Drawing IS the managed version of GDI+.
It's using GDI+ in its implementation. So your
images ARE GDI+ images.
Why do you need to use an HGLOBAL in a managed application?
If you need old school GDI BITMAPINFOHEADER stuff you
can certainly construct that info yourself from info
in your GDI+ System.Drawing.Bitmap objects.
For example, to extract 24bpp image data from a
System.Drawing.Bitmap:
using namespace System::Drawing;
using namespace System::Drawing::Imaging;
Bitmap ^bmp = ...;
Rectangle rect = Rectangle(0, 0, bmp->Width, bmp->Height);
BitmapData ^bmpData = bmp->LockBits(rect, ImageLockMode::Read, PixelFormat::Format24bppRgb);
BITMAPINFOHEADER bmiHeader;
bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
bmiHeader.biWidth = bmp->Width;
bmiHeader.biHeight = bmp->Height;
bmiHeader.biPlanes = 1;
bmiHeader.biBitCount = 24;
bmiHeader.biCompression = BI_RGB;
bmiHeader.biSizeImage = abs(bmpData->Stride) * bmpData->Height;
bmiHeader.biXPelsPerMeter = 0;
bmiHeader.biYPelsPerMeter = 0;
bmiHeader.biClrUsed = 0;
bmiHeader.biClrImportant = 0;
bmp->UnlockBits(bmpData);
Mark Salsbery
Microsoft MVP - Visual C++
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Let me clarify what I said and thanks for correcting that
Yes you are correct. I was just pointing out that the Images were using the managed version classes. What I hope to accomplish is:
I have one HGLOBAL. This is used to create an image of type System::Drawing::Bitmap.
HGLOBAL hdl = GloabalAlloc(BitmapImageSize);
PBITMMAPINFOHEADER bmih = (PBITMAPINFOHEADER)GlobalLock(hdl);
LPDWORD ImgBits = (LPDWORD)(bmih + sizeof(BITMAPINFOHEADER));
....
....
....
StretchDIBits()......
That gives me an image from an HGLOBAL
If I had an image already in memory, from some other means (loaded from file maybe), I want to then point that image to the HGLOBAL.
The reason for using those deprecated function is the type that is returned from functions in ActiveX controls that handle image acquisition is of HGLOBAL. It is then convenient to use those Global functions and since I am doing a mixed mode app thanks in large part to using C++/CLI I can do this.
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alleyes wrote: I want to then point that image to the HGLOBAL.
What does that mean?
You don't point something to an HGLOBAL.
You can allocate memory as an HGLOBAL and
copy data into that memory, just like you
did using an array in the thread below.
Mark Salsbery
Microsoft MVP - Visual C++
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I have ONE store of heap memory with a handle to it - HGLOBAL. What I am not articulating adequately is that instead of creating a new memory block, I would like to use a common one if that's at all possible with what I described. Is that possible using the LockBits method? Like I said previously, I have one block of heap space and assign that to one image from a picture box. I have actually two picturebox objects on my form and want to the ability to copy the image from the second picturebox to the main heap store that was allocated. This is what I feel is the disconnect.
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The HGLOBAL is just a handle to an allocated block
of memory (a BYTE array). You get a pointer to that
block of memory with GlobalLock().
You can copy whatever you want to it.
It's up to you to make sure that block is large enough to
hold what you write to it.
Mark Salsbery
Microsoft MVP - Visual C++
![Java | [Coffee]](https://www.codeproject.com/script/Forums/Images/coffee.gif)
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Mark Salsbery wrote: You get a pointer to that
block of memory with GlobalLock().
That's what I meant by pointer but mis-construed it a bit.
To summarize then. I can copy the bitmap data to this HGLOBAL using managed Bitmap classes? I do have the advantage of BITMAPINFOHEADER being available from the image that is to be copied from so I have most of that information which happens to be common to both the images in question
If copying to the memory block is the lock still in place or do you call an GlobalUnLock first.
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alleyes wrote: I can copy the bitmap data to this HGLOBAL using managed Bitmap classes?
You can't directly copy from managed to unmanaged memory.
You can use Marshal::Copy though. You can also wrap
the pointer in an UnmanagedMemoryStream object so you
can use any managed functionality that uses a Stream object.
For example, you could write a BMP file from a Bitmap to
memory in one line of code instead of building the headers
manually.
alleyes wrote: If copying to the memory block is the lock still in place or do you call an GlobalUnLock first.
You use the pointer while it's locked.
Mark Salsbery
Microsoft MVP - Visual C++
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Mark Salsbery wrote: You can't directly copy from managed to unmanaged memory.
You can use Marshal::Copy though
I fully intended using the Marshal class for copying.
Mark Salsbery wrote: You can also wrap
the pointer in an UnmanagedMemoryStream object so you
can use any managed functionality that uses a Stream object.
Now you threw me a bit. One of the things I was considering was saving the image to a managed memory stream object. Why consider unmanaged? By calling the Save method and then specifying BMP as the image type, I do get the BITMAPHEADERINFO.
This is what I'm building upon without doing the Save to Stream technique:
System::Drawing::Rectangle imgRect =
System::Drawing::Rectangle(0, 0,
MyImage->Width, MyImage->Height);
System::Drawing::Imaging::BitmapData^ bmpData =
MyImage->LockBits(imgRect,
System::Drawing::Imaging::ImageLockMode::ReadOnly,
System::Drawing::Imaging::PixelFormat::Format32bppRgb);
int byteCount = bmpData->Stride * MyImage->Height;
array<Byte>^ bmpBytes = gcnew array<Byte>(byteCount);
Marshal::Copy(bmpData->Scan0, bmpBytes, 0, byteCount);
MyImage->UnlockBits(bmpData);
Once I have the image in an array shouldn't I be copying it to the HGLOBAL? Or should the destination be the HGLOBAL and forget about the array?
modified on Wednesday, January 20, 2010 2:42 PM
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I think I have the solution:
MemoryStream^ ms = gcnew MemoryStream();
MyImage->Save(ms, System::Drawing::Imaging::ImageFormat::Bmp);
array<Byte>^ bits = gcnew array<Byte>(MyHeader->biSizeImage);
bits = ms->GetBuffer();
ms->Close();
Marshal::Copy(bits, 0, static_cast<IntPtr>(MyHGlobal), bits->Length);
Where:
MyHeader->biSizeImage is the member from the BITMAPINFOHEADER
MyHGlobal is the handle to the locked memory block.
I then throw an AccessViolationException at the copy call. I think that perhaps the array size may be bigger than the memory block.
I appreciate your help so far - I'm close!
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