Hi All,
I'm trying write an application which can copy an existing file (PRC or PDB)
in a Palm device.
Here I'm using Beaming technology used in Palm OS, namely ExgDBRead, and
ExgDBWrite.
Although this technology is used, the app will be run in a single device. I
found that this would be the easiest method to read a file since I do not
know the record structure of the file to be copied.
but there seems to be a problem with the code I written.
what I do is first read the file using ExgDBWrite and write to a database in
device.
code is as follows.
....
....
// write the file to a Temp Database
Err xx1 = ExgDBWrite (WriteDatabase, NULL, dbName, NULL, 0);
LocalID dbID;
UInt16 cardNo = 0;
Boolean needReset = false;
Boolean keepDates;
recCount = 0;
// read from the Temp Database and create a new file
error = ExgDBRead(ReadDatabase, NULL, NULL, &dbID, cardNo, &needReset,
keepDates);
....
....
Err WriteDatabase(const void *buffer, UInt32 *bytes, void *exgSocket)
{
LocalID dbID;
UInt16 cardNo = 0;
Boolean needReset;
Boolean keepDates;
xxCount++;
//change the creator ID and first character of the file type so it becomes
unique
if (xxCount == 1)
{
*( (char*)buffer + 0) = 'Q';
*( (char*)buffer + 60) = 'X';
*( (char*)buffer + 61) = 'X';
*( (char*)buffer + 62) = 'X';
*( (char*)buffer + 63) = 'X';
*( (char*)buffer + 64) = 'X';
}
void* rec;
void* recP;
UInt16 index = dmMaxRecordIndex;
MemHandle mH = DmNewRecord( TempDB , &index , (*bytes));
recP = (void*) MemHandleLock( mH );
rec = (void*)buffer;
DmWrite( recP , 0 , rec, *bytes );
MemHandleUnlock(mH);
DmReleaseRecord(TempDB , index , true );
return errNone;
}
Err ReadDatabase(void* dataP, UInt32* sizeP, void* userDataP)
{
MemHandle recordH =DmQueryRecord(TempDB,recCount);
void *rrr =(void*)MemHandleLock(recordH);
dataP = rrr;
*sizeP = MemHandleSize( recordH );
dataP = MemPtrNew( *sizeP );
for( int i = 0 ; i < *sizeP ; i++ )
*( (UInt8*) dataP + i ) = *( (UInt8*) rrr + i );
recCount++;
MemHandleUnlock(recordH);
return errNone;
}
It seems writing to the database part (ExgDBWrite) is OK. I checked the Temp
Database from another app (Insider) and it showed as 10 records written to
that Temp Database (the original PDB file i used contained 3 data records.
so in addition to this 3 records there were 7 more short records including
the header information).
When i ExgDBRead, the call back function (ReadDatabase) executes a random
number of times (most of the time 4 times). why is that ? i guess the call
back function should be run 10 times. Am i correct ?
someone pls help me to over come this problem.
thanks for reading this long description.
Merry X'mas to u all.
Dil �
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