Yet Another ExtDev Question

[Jaffob]

Sorry for so many extension development questions, but I hope you will all like my final product.

I am using the OPENFILENAME structure in my extension. Upon compiling, I get a warning saying I used an uninitialized variable. How should I go about initializing the structure?

Thanks for your time,
Jaffob

[James]

OPENFILENAME Filename;

will initialise it, whereas

OPENFILENAME * Filename;

will just create an empty pointer. If you want to use a pointer,

OPENFILENAME * Filename=new OPENFILENAME;

and then when you are done with it

delete Filename;

[Jaffob]

Thanks.
Another problem has arrived. When I enter my structure into the GetOpenFileName function, it compiles fine, but the MMF runtime crashes when the action is run. The Code:

OPENFILENAME sfn;
	sfn.lStructSize = sizeof(sfn);
	sfn.hwndOwner = MainHwnd;
	sfn.lpstrFilter = NULL;
	sfn.lpstrTitle = (char *)Param(TYPE_STRING);
	sfn.lpstrFilter = (char *)Param(TYPE_STRING);
	sfn.lpstrCustomFilter = NULL;
	sfn.nFilterIndex = Param(TYPE_INT);
	sfn.lpstrDefExt = (char *)Param(TYPE_STRING);
	sfn.lpstrFile = (char *)Param(TYPE_STRING);
	sfn.nMaxFile = MAX_PATH;
	sfn.lpstrFileTitle = NULL;

	GetOpenFileName(&sfn);

One more question: Is there a good way to set flags based on variables. Meaning, if the action accepts 5 variables of value 0 or 1, can I set flags some way that does not result in uncountable if statements.

[Dynasoft]

sfn.lpstrFile needs to point to a WRITABLE string of max size sfn.nMaxFile. A Param() isn't writable.

[Jaffob]

I created a variable at the top of main.cpp like this:

char * FilePath = NULL;

Then for lpstrFile I put:

sfn.lpstrFile = FilePath;

It still does not work. Is there something else I need to do?

[James]

Of course it's going to crash if you use a NULL pointer. You need to allocate some memory-

char * FilePath=new char[MAX_PATH];

and if you want to load the parameter into it,

strcpy(FilePath,(char *)Param(TYPE_STRING));

although it's sensible to do a check on the length, which you can figure out yourself

[Dynasoft]

Don't forget to delete the string after:
delete[] FilePath;

[James]

Alternatively, you can use rdPtr->rRd->GetStringSpace(MAX_PATH); instead of new, which borrows the memory from the runtime. MMF2 will free it automatically.

[Jaffob]

New code:

	LPRH rhPtr = rdPtr->rHo.hoAdRunHeader;
	HWND MainHwnd = rhPtr->rhHMainWin;

	char * FilePath = new char[MAX_PATH];

	OPENFILENAME sfn;
	sfn.lStructSize = sizeof(sfn);
	sfn.hwndOwner = MainHwnd;
	sfn.lpstrFilter = NULL;
	sfn.lpstrTitle = (char *)Param(TYPE_STRING);
	sfn.lpstrFilter = (char *)Param(TYPE_STRING);
	sfn.lpstrCustomFilter = NULL;
	sfn.nFilterIndex = Param(TYPE_INT);
	sfn.lpstrDefExt = (char *)Param(TYPE_STRING);
	sfn.lpstrFile = FilePath;
	sfn.nMaxFile = MAX_PATH;
	sfn.lpstrFileTitle = NULL;
	
	int exist = Param(TYPE_INT);
	int showhidden = Param(TYPE_INT);
	int readonly = Param(TYPE_INT);
	int shortcut = Param(TYPE_INT);
	int recent = Param(TYPE_INT);

// This is where I need help with flags

	if(exist==0 && showhidden==0 && readonly==0 && shortcut==0 && recent==0)  sfn.Flags = OFN_HIDEREADONLY;
	if(exist==0 && showhidden==0 && readonly==0 && shortcut==0 && recent==1)  sfn.Flags = OFN_HIDEREADONLY|OFN_DONTADDTORECENT;
	if(exist==0 && showhidden==0 && readonly==0 && shortcut==1 && recent==0)  sfn.Flags = OFN_HIDEREADONLY|OFN_NODEREFERENCELINKS;
	if(exist==0 && showhidden==0 && readonly==1 && shortcut==0 && recent==0)  sfn.Flags = 0;
	if(exist==0 && showhidden==1 && readonly==0 && shortcut==0 && recent==0)  sfn.Flags = OFN_HIDEREADONLY|OFN_FORCESHOWHIDDEN;
	if(exist==1 && showhidden==0 && readonly==0 && shortcut==0 && recent==0)  sfn.Flags = OFN_HIDEREADONLY|OFN_FILEMUSTEXIST;
	if(exist==0 && showhidden==0 && readonly==0 && shortcut==1 && recent==1)  sfn.Flags = OFN_HIDEREADONLY|OFN_NODEREFERENCELINKS|OFN_DONTADDTORECENT;
	if(exist==0 && showhidden==0 && readonly==1 && shortcut==0 && recent==1)  sfn.Flags = OFN_DONTADDTORECENT;
	if(exist==0 && showhidden==1 && readonly==0 && shortcut==0 && recent==1)  sfn.Flags = OFN_HIDEREADONLY|OFN_DONTADDTORECENT|OFN_FORCESHOWHIDDEN;
	if(exist==1 && showhidden==0 && readonly==0 && shortcut==0 && recent==1)  sfn.Flags = OFN_HIDEREADONLY|OFN_DONTADDTORECENT|OFN_FILEMUSTEXIST;
	if(exist==0 && showhidden==0 && readonly==0 && shortcut==1 && recent==1)  sfn.Flags = OFN_HIDEREADONLY|OFN_DONTADDTORECENT|OFN_NODEREFERENCELINKS;


	GetOpenFileName(&sfn);

	delete[] FilePath;

The Good News: It does not crash when the action is run.
The Bad News: Nothing at all happens when the action is run.

Why doesn't it do anything?

Thanks again for all the help.

[James]

What do you expect it to do?

Also, your huge block of if statements can be replaced by:

sfn.Flags=0;

if(!readonly)	sfn.Flags |= OFN_HIDEREADONLY;
if(recent)	sfn.Flags |= OFN_DONTADDTORECENT;
if(shortcut)	sfn.Flags |= OFN_NODEREFERENCELINKS;
if(showhidden)	sfn.Flags |= OFN_FORCESHOWHIDDEN;
if(exist)	sfn.Flags |= OFN_FILEMUSTEXIST;