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Dear all,
i'm a new guy in c++, i'm making a program using MFC dialogue, i need to pass an array value from one dialogue to another, but the other dialogue doesn't recognise the variable even i've include the previous dlg header file, so, how to do that? thanks very much!!
Will one dialog call the other dialog or will both be open and active simultanously ?
If one dialog openes the other one, like showing details, you can pass your variable(s) in the constructor of the second dialog.
my application is click on the button of the dialogue will show the other dialogue...acutally i dun understand how to use constructor to pass the value in this way, is there any other method? thanks~
Moved to Windows board.
Your first post is a bit vague. Why not post the code so we can see what you're doing wrong?
As long as you call the base constructor CDialog with the params it requires you can then add params to your CDialog derived class constructor as you see fit.
So don't feel as if you cannot add your own parameters to the constructor just because you have to init the base class constructor.
i use these code:
i declare details in both dialogue file, and
Code:
resultDlg result;
result.details=details;to pass the value to the result dialogue from the input dialogue where result is the result dialogue object.
but the result is the dailogue appear said that the debug assertion fail.
what should i do to pass the value between dialgue? thanks!!
That can't be called code and it doesn't help at all.
Post a snippet of your class declaration and the code that creates the variable you want to assign and the code where you DO assign it to the class. That, at the very least, should help.
That snippet does not help since it won't even work.
If you are subclassing a dialog in MFC then you can pass data from the dialog back to the caller in several ways.
1. In the designer set a variable to be associated with the control. In code provide a means to get the value of this variable. When the dialog user presses OK call CDialog::UpdateData(TRUE). This will update the variables associated with controls to the value that is in the controls at the time the user pressed OK. Retrieve these variables from another class or object via pointers to the class or some other method.
2. Set the variables manually by scanning the controls, retrieving their state (text, value, or other), storing that in class members, and retrieving later via pointers to the class or some other method.
In both instances this requires that the CDialog derived object exists even after the user pressed OK and the dialog disappears or becomes hidden. If the CDialog object does not exist then the variables do not exist and you will have a serious problem if you try to access the object since it does not exist.
Novacain also showed me this at one time and it has been a huge help. You can get a pointer to your main window by doing this:
You can use this pointer to access variables in your CFrameWnd derived class. Very handy.Code:CMainFrame *ptrFrame = (CMainFrame *)AfxGetMainWnd();
this is my code:
the result dialogue show nothing, where my input exist in the database, any thing need to be changed in tmy code? thanks a lot!Code:Search.cpp
void ASearch::OnBnClickedButton1() //ok button to search
{
searchNumber();
if (resultCount>0){
Search_result result;
result.DoModal();
}else if (resultCount==0){
edittxt.SetWindowText(L"un ok"); }
UpdateData(TRUE);
// TODO: Add your control notification handler code here
}
void Search::searchNumber(){
busDB bus_db;
resultCount=0;
int dbsize = bus_db.getDbSize();
CString editbxNo;
edittxt.GetWindowText(editbxNo);
Bus AS_resultdb[817];
Search_result as_result;
for(int i=1; i<=100; i++){
if(bus_db.getNumber(i).Find(editbxNo)>=0){
details = bus_db.getRemark(i)+bus_db.getNumber(i)+bus_db.getTitle(i);
as_result.details=details;
UpdateData(TRUE);
++resultCount;
}
}
}
Search_result.cpp:
void ASearch_result::OnLbnSetfocusList5() //listbox to start listing details
{
// TODO: Add your control notification handler code here
this->AS_result_list.AddString(details);
}
1) Your identation is horrible.
2) Don't just use generic names such as button1. NAME your controls.
3) You're expecting a local object to keep its data when you construct another, NEWER object of the same type later? Come on. Once your dialog goes out of scope, everything it holds will be destructed as well.
i declare the public variable in both header files, and use this:Quote:
Originally Posted by Elysia
as_result.details=details;
and retrieve the data in result dialogue,
can't it work? then what should i do? thank you
Your indentation is so horrible, I had to fix it for you.Code:// Search.cpp
void ASearch::OnBnClickedButton1() //ok button to search
{
searchNumber();
if (resultCount > 0)
{
Search_result result; // YOU ARE CREATING A NEW OBJECT
result.DoModal();
}
else if (resultCount==0)
{
edittxt.SetWindowText(L"un ok");
}
UpdateData(TRUE);
// TODO: Add your control notification handler code here
}
void Search::searchNumber()
{
busDB bus_db;
resultCount = 0;
int dbsize = bus_db.getDbSize();
CString editbxNo;
edittxt.GetWindowText(editbxNo);
Bus AS_resultdb[817];
Search_result as_result; // AGAIN, YOU ARE CREATING A NEW, LOCAL OBJECT.
for (int i = 1; i <= 100; i++)
{
if (bus_db.getNumber(i).Find(editbxNo) >= 0)
{
details = bus_db.getRemark(i) + bus_db.getNumber(i) + bus_db.getTitle(i);
as_result.details = details;
UpdateData(TRUE);
++resultCount;
}
}
}
//Search_result.cpp:
void ASearch_result::OnLbnSetfocusList5() //listbox to start listing details
{
// TODO: Add your control notification handler code here
this->AS_result_list.AddString(details);
}
Look where it's red - see? You're creating local objects! MFC works on the principle that all dialogs are objects - when they go our of scope, your dialog is destroyed.
So what are you doing wrong? You're creating a dialog class, assigning data to it, it then gets destroyed, along with all its data. Then you're creating a NEW dialog class and expect the data to still be there.
I suggest you read about classes, objects, references and pointers.
http://www.cprogramming.com/tutorial/
There are several options:
1. Create the search object on the heap and retrieve the values from it later.
2. Store the results in class members after the search dialog is done. Then when it goes out of scope you will have saved the important data you may need for later.
Not to mention there's one dialog and (possibly) more than one result, resulting in overwriting the last find.
Quote:
Originally Posted by Elysia
do u mean when i create the new dialogue object the data will be destroyed as well? i had correct the code as u pointed but the result dialogue is still empty, where is the problem? should i use pointer? and how? could u suggest some code to me? thanks you so much!!
thank you for your suggestion, but i dun know how to use heap, is it a must to use heap or is there any other way? thanks!Quote:
Originally Posted by Bubba
Well in C++, it'd be new and delete. Look them up.
Eg, https://msdn2.microsoft.com/en-us/li...ba(VS.71).aspx
I suggest you learn C++ programming before attempting to tackle anything in MFC.
I agre with the suggestions above.....
Easiest soulution....
Store the DB data in the Search cpp (as a public member variable or as a property).
From the code this looks like the 'Details' variable.
In the 'results' dialog set/get the results by using (or similar)
GetParent()->Details
actually i have got the result in the list box now, but i need to click on the list box once to display the result so that i think there's problem in my code before...
however, now a problem arises, how to display the result without click on the list box??
Do it in your dialog's InitDialog procedeure.
Sounds like a drawing issue (data is in LV but not asked to be drawn to the screen until you click).Quote:
Originally Posted by mr_empty
Add a call to redraw the dlg
InvalidateRect
UpdateWindow
my result dialog is not called by initDialog cpp file...Quote:
Originally Posted by Elysia
Do you actually know anything of MFC?
Override the class's InitDialog function. There's where you put init code.
Also, from what I can see, the list is updated once it recieves the focus. I don't know if a child window will recieve focus when a list is created.
thanks for reply, i'm a beginner of MFC and i'm still kearnning when i'm working on this program..Quote:
Originally Posted by Elysia
u said do it in the init code, but actually how's the code? just call the dialogue ? thnaks~
o ic, just add string into the list in the oninitdialog can do this, thanks
Yes, it can, and it's the best place to do it.