C / C++ / MFC Discussion Boards

Zac Howland26-Jul-06 5:40

26-Jul-06 5:40

Why not just use the GetBitmapBits/SetBitmapBits (and CGdiObject::GetObject) to get the bits from images 1 and 2, create a byte array that is the size of the sum of both those arrays (which should be double the size of either one if the bitmaps are the same size), copy the bytes from image 1 to the first part of the new array, and image 2 to the last part of the new array and then use SetBitmapBits on a newly created CBitmap object?

If you decide to become a software engineer, you are signing up to have a 1/2" piece of silicon tell you exactly how stupid you really are for 8 hours a day, 5 days a week

Zac

Re: Create a bitmap

valikac26-Jul-06 6:47

valikac

26-Jul-06 6:47

another approach is create a bitmap sized to fit both source bitmaps. arrange the bitmaps via bitblt()

Kuphryn

Two Documents in an Application

narayanagvs26-Jul-06 4:55

narayanagvs

26-Jul-06 4:55

Hi
Can we have two CDocument derived classes in an MDI application??

Re: Two Documents in an Application

led mike26-Jul-06 5:46

led mike

26-Jul-06 5:46

Yes

Re: Two Documents in an Application

BlitzPackage26-Jul-06 7:36

BlitzPackage

26-Jul-06 7:36

Thus the name MDI = Multiple Document

Strange error i cannot fathom

eeyor66626-Jul-06 4:33

eeyor666

26-Jul-06 4:33

hey can anyone help me sort this? the weird thing is my program ran at first but now if i try and run i get this debug error!

*********************************************************************************************
*": warning C4267: 'argument' : conversion from 'size_t' to 'DWORD', possible loss of data"
*********************************************************************************************

Sniff | :^)

If i'm not dead enough for life, am i alive enough for death?

Re: Strange error i cannot fathom

RChin26-Jul-06 4:46

RChin

26-Jul-06 4:46

Smells like an stl issue.
You will get this type of message if you do something like this:

<br />
std::vector<long> vecLong;<br />
int n = vecLong.size();<br />

A lot of the stl classes returns a size_t numeric data type (instead of say, int, long etc).
Its not an error, but you should be aware of any overflow issues. If you are sure that your DWORD variable has enough range to accomodate the stl's size_t number, then just do a simple type cast.

<br />
std::vector<long> vecLong;<br />
int n = static_cast<int>(vecLong.size());<br />

I Dream of Absolute Zero

Re: Strange error i cannot fathom

David Crow26-Jul-06 4:48

David Crow

26-Jul-06 4:48

The compiler is telling you exactly what is wrong. Show the line of code in question.

"Money talks. When my money starts to talk, I get a bill to shut it up." - Frank

"Judge not by the eye but by the heart." - Native American Proverb

Re: Strange error i cannot fathom [modified]

toxcct26-Jul-06 5:02

toxcct

26-Jul-06 5:02

this is not an error. it is just a warning.

the compiler warns you about the fact that you copy some value of a particuliar type into a smaller type, hence the "possible loss of data".

what you can do to avoid this is :
- make the two types identical
- explicitely cast while assigning the value
- disable temporarily/totally the warning using the #pragma warning(disable:4267) statment...

Re: Strange error i cannot fathom

Zac Howland26-Jul-06 5:06

Zac Howland

26-Jul-06 5:06

toxcct wrote:
- disable temporarily/totally the warning using the #pragma comment(disable:4267) statment...

I believe you meant #pragma warning(disable:4267).

If you decide to become a software engineer, you are signing up to have a 1/2" piece of silicon tell you exactly how stupid you really are for 8 hours a day, 5 days a week

Zac

Re: Strange error i cannot fathom

toxcct26-Jul-06 5:09

toxcct

26-Jul-06 5:09

Zac Howland wrote:
believe you meant #pragma warning(disable:4267).

yup, typo

TOXCCT >>> GEII power

[VisualCalc 3.0 updated ][Flags Beginner's Guide new! ]

Re: Strange error i cannot fathom

Zac Howland26-Jul-06 5:03

Zac Howland

26-Jul-06 5:03

Are you compiling as 64-bit by chance? I believe size_t is a 64-bit integer on 64-bit platforms whereas DWORD (which is just an unsigned long) is always 32-bits. Thus, if you try to implicitly cast a size_t to a DWORD, it will give you that warning. To get around it, either ignore it, use bitshift operations to get the lower 32-bits, or use static_cast to explicitly cast it to a DWORD.

If you decide to become a software engineer, you are signing up to have a 1/2" piece of silicon tell you exactly how stupid you really are for 8 hours a day, 5 days a week

Zac

conversion

RockyJames26-Jul-06 4:32

RockyJames

26-Jul-06 4:32

hi
i have funtion named change(long lngNo,unsigned char* pData);

where some times i send intger data,float data ,BOOL data as second parameter.How do i convert integer ,float ,BOOL to unsigned char*.

thanks in before

james

Re: conversion

David Crow26-Jul-06 4:45

David Crow

26-Jul-06 4:45

RockyJames wrote:
How do i convert integer ,float ,BOOL to unsigned char*.

Use the address-of operator (&). For example:

int x;
change(5L, &x);

"Money talks. When my money starts to talk, I get a bill to shut it up." - Frank

"Judge not by the eye but by the heart." - Native American Proverb

Re: conversion

RockyJames26-Jul-06 4:53

RockyJames

26-Jul-06 4:53

error C2664: : cannot convert parameter 2 from 'int *__w64 ' to 'unsigned char *'

Re: conversion

David Crow26-Jul-06 5:03

David Crow

26-Jul-06 5:03

You'll need to cast it, since change() is expecting an unsigned char *.

Why are you trying to make a one-size-fits-all function?

"Money talks. When my money starts to talk, I get a bill to shut it up." - Frank

"Judge not by the eye but by the heart." - Native American Proverb

Re: conversion

toxcct26-Jul-06 5:05

toxcct

26-Jul-06 5:05

can't you write several overloads of the function, which every func receive the right type ?

TOXCCT >>> GEII power

[VisualCalc 3.0 updated ][Flags Beginner's Guide new! ]

Re: conversion

Zac Howland26-Jul-06 5:13

Zac Howland

26-Jul-06 5:13

RockyJames wrote:
i have funtion named change(long lngNo,unsigned char* pData);

where some times i send intger data,float data ,BOOL data as second parameter.How do i convert integer ,float ,BOOL to unsigned char*.

It is very bad practice to write a one-size-fits-all function. If you are trying to do something with the bytes (i.e. send them across a network using sockets), that is one thing, but if you are trying to decrease the number of methods you need to write for a given operation that doesn't involve direct byte transmissions, then this is the wrong approach.

A cleaner way of doing it would be to:

typedef unsigned long ulong;
typedef unsigned char byte;
// hide this method so that it isn't exposed
void change(ulong size, byte* data)
{
	// do something with data
}

// this is the exposed method
template<class T> void change(const T& data)
{
	change(sizeof(T), (byte*)&data);
}

If you decide to become a software engineer, you are signing up to have a 1/2" piece of silicon tell you exactly how stupid you really are for 8 hours a day, 5 days a week

Zac

Re: conversion

RockyJames26-Jul-06 16:00

RockyJames

26-Jul-06 16:00

The function is not written by me,it is one of the function in control.that`s the problem..so how can i send integer ,float ,BOOL in BYTE or unsinged char format.....?

Re: conversion

Zac Howland26-Jul-06 19:14

Zac Howland

26-Jul-06 19:14

If you have the ability to refactor the function, you should.

That said, if you are just looking to get something working with it, you can cast anything in memory to a char* (or anything else for that matter) by taking the address of it (note that it is not necessarily safe to do, but is possible):

struct MyStruct
{
// some stuff here
};

MyStruct data;
change((char*)&data, sizeof(MyStruct));

If you decide to become a software engineer, you are signing up to have a 1/2" piece of silicon tell you exactly how stupid you really are for 8 hours a day, 5 days a week

Zac

In C++, how get the value and key in the IDictionary

chenxiujie26-Jul-06 4:19

chenxiujie

26-Jul-06 4:19

In C++, how get the value and key in the IDictionary

Thanks.

Re: In C++, how get the value and key in the IDictionary

David Crow26-Jul-06 4:33

David Crow

26-Jul-06 4:33

Are you referring to the Keys and Values properties?

"Money talks. When my money starts to talk, I get a bill to shut it up." - Frank

"Judge not by the eye but by the heart." - Native American Proverb

Start a powerpoint slideshow from C++ (.pps file)

Remco Hoogenboezem26-Jul-06 3:54

Remco Hoogenboezem

26-Jul-06 3:54

Hi I would like to start a powerpoint slideshow from C++ the way it is done by the shell. I think this is possible by using OLE automation but I could not find a good example to help me on the way. I prefere to use slideshow viewer only if this is possible. (don't use powerpoint) I am not using MFC.

Thanks: cool:

Re: Start a powerpoint slideshow from C++ (.pps file)

David Crow26-Jul-06 3:59

David Crow

26-Jul-06 3:59

Remco Hoogenboezem wrote:
Hi I would like to start a powerpoint slideshow from C++ the way it is done by the shell.

Then use ShellExecute().

"Money talks. When my money starts to talk, I get a bill to shut it up." - Frank

"Judge not by the eye but by the heart." - Native American Proverb

Re: Start a powerpoint slideshow from C++ (.pps file)

Hamid_RT26-Jul-06 5:24

Hamid_RT

26-Jul-06 5:24

See ShellExecute[^]

WhiteSky

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.