C / C++ / MFC

31-Aug-07 22:30

I have to load a bitmap in a dialog box.
I have loaded the Image in bitmap resource and then I tried the below code

HBITMAP hBitmap=(HBITMAP)LoadBitmap(AfxGetInstanceHandle,"IDB_IMAGE");

but when i execute this statement the hBitmap is 0x0000000.

Can anyone give me some suggestions.

Is there any way to transparent the background of a button

S.Yamini

chandu00431-Aug-07 22:35

31-Aug-07 22:35

even i had this problem once upon a time.
do you want to load it in the image box at run time or is it sufficient at design time?

yaminisridaran31-Aug-07 22:39

31-Aug-07 22:39

Thanks for ur reply I have to load it in runtime on a dialog box from bitmap resource.Can u tell how to get a DC of dialog box. I tried the code below in OnIntiDialog but it does not work

CDC pDC;
pDC=Get();
pDC->TextOut(0,0,"Sample");

The Text "Sample" did not display but when i implemented the code in OnPaint with dc from CPaint it works. Can u suggest me some ways to solve it

S.Yamini

chandu00431-Aug-07 22:50

31-Aug-07 22:50

it is a bit easy task to load an image, on a dialog
but before i proceed to suggest you the best technique, that suits your application,
please answer these questions.
1.is your image constant throughout the application, or it may change based on the context dynamically.
2.have you already created a resource for that image?
3.if you have only one image and want to see it on the screen, then you can link it statically.
4.if you have to load images, based on the context(condition) then you can take that many number of controls and toggle them as per your requirement.

yaminisridaran31-Aug-07 22:54

31-Aug-07 22:54

I have to change the image dynamically according to the move movement on the dialog box

S.Yamini

chandu00431-Aug-07 22:59

31-Aug-07 22:59

how many images you have to the max.

yaminisridaran31-Aug-07 23:02

31-Aug-07 23:02

I have two images.I has to toggle according to the mouse movement. I nned to know how to get the dc of the dialog control.Please

S.Yamini

chandu00431-Aug-07 23:12

31-Aug-07 23:12

assign a member variable to that control,
then, m_ctrl.GetDC();

chandu00431-Aug-07 23:10

31-Aug-07 23:10

are you using the bitmap control you have in your tool bar,
or is it ok for you if i give my active X control which can take any bitmap image any time. what all you have to do is, you have to specify the file path.
for example, ctrl.SetImage("C:\\image1.bmp");
then after some time, ctrl.SetImage("C:\\image2.bmp");
is it ok for u.

Bhavesh Bagadiya31-Aug-07 22:44

31-Aug-07 22:44

you should use LoadBitmap as

HBITMAP bitmapHandle = LoadBitmap(AfxGetInstanceHandle(), MAKEINTRESOURCE(IDB_IMAGE));

yaminisridaran31-Aug-07 22:47

31-Aug-07 22:47

Thanks it works can u suggest me some ways for getting the DC. I have added the code before.

S.Yamini

Bhavesh Bagadiya31-Aug-07 22:48

31-Aug-07 22:48

You should use

CPaintDC dc(this);

dc.TextOut(...);

if u are intended to use this function in OnPaint() method, otherwise u should use

CClientDC dc(this);
dc.TextOut(...);

yaminisridaran31-Aug-07 22:52

31-Aug-07 22:52

I tried CClientDC but it did not work.Should i have to change any property of the dialog box

S.Yamini

Bhavesh Bagadiya31-Aug-07 22:54

31-Aug-07 22:54

If u want it use it with CDC(though not recommended) u can use it like below,

PAINTSTRUCT pStruct;
CDC* pDC = BeginPaint(&pStruct);
//Use CDC here.

pDC->DoWhatEverYouWantToDo(); // !!

EndPaint(&pStruct); //Don't forget this o'wise sometime result would be disastrous.!!

(For your knowledge, CClientDC and CPaintDC both do BeginPaint in Constructor and EndPaint in Destructor..)

yaminisridaran31-Aug-07 22:57

31-Aug-07 22:57

I tried it in onintidialog it does not work. Can u suggest some more ways to solve this issue

S.Yamini

Bhavesh Bagadiya31-Aug-07 23:02

31-Aug-07 23:02

after onInitdialog completes, whole dialog being repainted so your graphics erased. one solution is to override OnEraseBkgnd and return TRUE from it so System will never erase background. but be careful, system never erase Background !!

yaminisridaran31-Aug-07 23:05

31-Aug-07 23:05

I cannot use erasebk bcoz i have to toggle the images.

S.Yamini

Bhavesh Bagadiya31-Aug-07 23:10

31-Aug-07 23:10

so whats problem will be in toggling images after overriding eraseBk ??? whatever painting done by you will be there, only system won't paint its default bkground ...

yaminisridaran31-Aug-07 23:13