|
|
|
Essentially, there are four different methods to read resources from a c-tree Plus table. Read all table resources, read all resources starting past a resource type and number, read a specific resource by specifying the Resource Type and Resource Number, or read a resource by specifying a Resource Name. Described below are examples of each method.
Read all c-tree Plus Resources from a Table
Read all resource starting with the first resource by calling method CTResource::First() and then read the remaining resources by calling method CTResource::Next(). To read the first resource in a table, call the following CTResource method:
CTBOOL CTResource::First(CTBOOL lock = NO) const;
CTResource::First() retrieve the first resource stored in a table.
CTResource::First() returns YES if the resource was found or NO if no resource was found. If an error is detected, CTResource::First() throws a CTException exception.
To read all other resources of a table call the following CTResource method:
CTBOOL CTResource::Next(CTBOOL lock = NO) const;
CTResource::Next() retrieves the next resource stored in a table, after a successful call to CTResource::First() is made.
CTResource::Next() returns YES if the resource was found or NO if no resource was found. If an error is detected, CTResource::First() throws a CTException exception.
Example
void DisplayAllResources(const CTTable& hTable)
{
CTResource* hRes = new CTResource(hTable);
try
{
// get the first resource
if (hRes->First())
{
do
{
// display resource type, number and name
printf("Resource type: %u, number: %u",
hRes->GetType(), hRes->GetNumber());
}
while (hRes->Next());
}
}
catch (CTException &err)
{
printf("Error %d - %s\n", err.GetErrorCode(), err.GetErrorMsg());
}
delete hRes;
}
Read all c-tree Plus Resources Given a Starting Point from a Table
Read all resources starting from a given resource type and number by calling method CTResource::Next(). Start by instantiating a resource object setting the resource type and a resource number and then call CTResource::Next(). In this case a resource is found if its type is greater or equal to the specified type and its number is greater than the specified number.
Example
// read resources with type >= type and number > 0
void DisplayResources(const CTTable& hTable, ULONG type)
{
CTResource* hRes = new CTResource(hTable, type, 0);
try
{
while (hRes->Next())
{
printf("Resource type: %u, number: %u",
hRes->GetType(), hRes->GetNumber());
}
}
catch (CTException &err)
{
printf("Error %d - %s\n", err.GetErrorCode(), err.GetErrorMsg());
}
delete hRes;
}
Read a Specific Plus Resources from a Table
Read a specific resource by providing exact resource type and number by calling CTResource::Find():
CTBOOL Find(ULONG type, ULONG number, CTBOOL lock = NO) const;
Locates and retrieves a resource in a table based on type and number.
CTResource::Find() returns YES if the resource was found or NO if this particular resource was not found. If an error occurs, CTResource::Find() throws a CTException exception.
Example
// display a particular resource
void DisplayResource(const CTTable& hTable, ULONG type, ULONG number)
{
CTResource* hRes = new CTResource(hTable);
try
{
if (hRes->Find(type, number))
{
printf("Resource type: %u, number: %u, name: %s\n",
hRes->GetType(), hRes->GetNumber(),
hRes->GetName().c_str());
}
else
printf("Resource %d,%d not found\n", type, number);
}
catch (CTException &err)
{
printf("Error %d - %s\n", err.GetErrorCode(), err.GetErrorMsg());
}
delete hRes;
}
Read a c-tree Plus Resources by Name from a Table
Read a resource by providing its name by calling CTResource::Find():
CTBOOL CTResource::Find(const CTString& name, CTBOOL lock = NO) const;
CTResource::Find() locates and retrieves a resource by name. c-tree Plus cannot guarantee unique resource names.
CTResource::Find() returns YES if the resource is located or NO if no resource is located. If errors are detected a CTException exception object is thrown.
Example
// display a particular resource by name
void DisplayResource(const CTTable& hTable, const CTString& name)
{
CTResource* hRes = new CTResource(hTable);
try
{
if (hRes->Find(type, name))
{
printf("Resource type: %u, number: %u, name: %s\n",
hRes->GetType(), hRes->GetNumber(),
hRes->GetName().c_str());
}
else
printf("Resource %s not found\n", name.c_str());
}
catch (CTException &err)
{
printf("Error %d - %s\n", err.GetErrorCode(), err.GetErrorMsg());
}
delete hRes;
}
