Hi All,
I'm trying to use the callback function with the list(LstSetDrawFunction) to
create a dynamic list. Everything compiles successfully, but during debugging, I only
saw the name of the first student appearing on the dynamic list like this:
Alex
Alex //should be other name
Alex //should be other name
Alex //should be other name
Alex //should be other name
Alex //should be other name
Alex //should be other name
... until the end of the list. Thus, I use a (for) loop in the call back function and
I obtain the same as the above except this time, it's the last student's name =(
I'm sorry for asking such a "newbie" question but I hope someone could tell me what
actually is wrong or anything I'm missing.
typedef struct {
Int32 studentID;
const char *Name;
const char *Class;
const char *Gender;
} Student;
typedef struct {
Int32 studentID;
char Name[1]; // actually may be longer than 1
} PackedStudent;
static void DrawCharsToFitWidth(const Char *s, RectanglePtr r)
{
Int16 stringLength = StrLen(s);
Int16 pixelWidth = r->extent.x;
Boolean truncate;
// FntCharsInWidth will update stringLength to the
// maximum without exceeding the width
FntCharsInWidth(s, &pixelWidth, &stringLength, &truncate);
WinDrawChars(s, stringLength, r->topLeft.x, r->topLeft.y);
}
//Call back Function
static void DrawStudentInList(Int16 itemNumber, RectanglePtr bounds, Char **txt)
{
#pragma unused(txt)
#pragma unused(itemNumber)
MemHandle h;
PackedStudent *psr;
UInt16 NumRecors;
ListPtr list = (ListPtr) GetObjectFromActiveForm(MainStudentsNameList);
NumRecors = DmNumRecords(gDatabase);
/*THIS IS THE FOR LOOP THAT I'VE ADD*/
for (indx=0; indx <NumRecors; indx++)
{
h = DmQueryRecord(gDatabase, indx);
psr = (PackedStudent *) MemHandleLock(h);
DrawCharsToFitWidth(psr->Name, bounds);
MemHandleUnlock(h);
}
}
// Dynamic Function
static void FillListWithName(ListType *lst)
{
const int kCardNumber = 0;
const char *kTag = "test-DB";
Err err;
LocalID DbID;
ListPtr list;
FormPtr frmP;
UInt16 NumRecor;
DbID = DmFindDatabase(kCardNumber, kTag);
if(!DbID)
err = DmGetLastErr;
else {
gDatabase= DmOpenDatabase(kCardNumber, DbID, dmModeReadOnly);
if(!gDatabase)
err = DmGetLastErr;
}
list = (ListPtr) GetObjectFromForm(frmP, MainStudentsNameList);
NumRecor = DmNumRecords(gDatabase);
LstSetDrawFunction(list, DrawStudentInList);
LstSetListChoices(list, NULL, (Int16) NumRecor);
LstSetSelection(list, 0);
}
Sorry for the long post.
Many Thanks
Regards
Lauren
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