CODEWITHSUNDEEP
c++pointersmfcscope
HansElsen
HansElsen

Reputation: 1753

C++ loss of variables

I have a CEdit and I want to extract the data using this.

wchar_t *temp = (wchar_t*)dialog.editbox.GetBuffer(0);
dialog.editbox.ReleaseBuffer();

Now i want to save this text in a object pointer like this:

selectedShape->setText(temp);

This work perfect, but only as long as you are in the scope of the method, because when I do a file save later, the text is not in the object anymore.

Does anybody know how I can save this wchar_t* for later?

Upvotes: 0

Views: 143

Answers (2)

Brady
Brady

Reputation: 10357

The temp pointer is pointing to data that goes out of scope, so you'll need to dynamically allocate memory to store the value. Something like this should work:

// Updated to use wstring, thanks praetorian
std::wstring tempStr((wchar_t*)dialog.editbox.GetBuffer(0));

Or:

int length = /*figure out the length here*/;
wchar_t *temp = new wchar_t[length];
memcpy(temp, dialog.editbox.GetBuffer(0), length*sizeof(wchar_t));
// dont forget to delete it like this: delete [] temp;

Upvotes: 1

HostileFork says dont trust SE
HostileFork says dont trust SE

Reputation: 33607

As @Prætorian says, your code seems to be missing a step of where you work with a CString class whose buffer you are getting.

http://msdn.microsoft.com/en-us/library/aa314880(v=vs.60).aspx

If at all possible, avoid using dynamic memory solutions. Instead, pass around your temp by value as a CString object that will manage its own memory. The stock Window setText functions take string pointers (which CString can implicitly cast to) and will copy the underlying string data. If you write your own objects, hold CString objects as members by value.

(I'll add my usual "The 90s called, they want their framework back" disclaimer here. Try Qt.)

Upvotes: 2

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