Descriptors example code

Found in: epoc32ex\Base\BufsAndStrings\Desc\BinaryData

The example shows how descriptors can handle general binary data by explicitly using the 8 bit descriptor class variants TBufC8<TInt>, TBuf8<TInt>, TPtr8 etc.

Contrast this with examples where descriptors contain text. These examples almost always use the non-explicit forms TBufC<TInt>, TBuf<TInt>, TPtr etc; these are typedef'd to the 16 bit variant.

Run the example either under WINS or on the ARMI platform.

• TBuf8<TInt>: 8 bit variant modifiable buffer descriptor, derived from TDes8.

Found in: epoc32ex\Base\BufsAndStrings\Desc\Buffer

This example shows the basic idea of buffer descriptors and how they are used.

Run the example either under WINS or on the ARMI platform

• TBuf<TInt>: modifiable buffer descriptor, derived from TDes

• TBufC<TInt>: constant buffer descriptor, derived from TDesC

• TPtr: modifiable pointer descriptor, derived from TDes

Found in: epoc32ex\Base\BufsAndStrings\Desc\InFunct

This example shows how descriptors can be used in function interfaces. Specifically, it shows the use of:

• const TDesC& aString

• TDes&

• const TDesC8& aBuffer

• TDes8& aBuffer

as function arguments.

Run the example either under WINS or on the ARMI platform

• TBuf<TInt>: modifiable buffer descriptor, derived from TDes

• TBufC<TInt>: constant buffer descriptor, derived from TDesC

• TPtr: modifiable pointer descriptor, derived from TDes

• TPtrC: constant pointer descriptor, derived from TDesC

• HBufC: heap buffer descriptor

Found in: epoc32ex\Base\BufsAndStrings\Desc\HeapBuffer

The example shows use of the HBufC heap buffer descriptor and:

• how it can be created using the HBufC::NewL() static function

• how it can be reallocated using the ReAllocL() function

• how its data can be changed through a TPtr constructed by calling the Des() function

Run the example either under WINS or on the ARMI platform

• HBufC: heap buffer descriptor

• TPtr: modifiable pointer descriptor, derived from TDes

• CleanupStack: a cleanup stack

Found in: epoc32ex\Base\BufsAndStrings\Desc\Modifier

The example shows the use of descriptor functions which can modify the descriptor. These are the functions defined and implemented by the TDes class: for example SetLength(), Copy() and Insert().

Run the example either under WINS or on the ARMI platform

• TDes: modifiable descriptor

• TBuf<TInt>: modifiable buffer descriptor, derived from TDes

• TPtr: modifiable pointer descriptor, derived from TDes

Found in: epoc32ex\Base\BufsAndStrings\Desc\NonModifier

The example shows the use of descriptor functions which do not modify the descriptor. These are the functions defined and implemented by the TDesC class; for example Length(), Size() and Compare().

Run the example either under WINS or on the ARMI platform

• TDesC: constant descriptor

• TBufC<TInt>: constant buffer descriptor, derived from TDesC

• TPtrC: constant pointer descriptor, derived from TDesC

Found in: epoc32ex\Base\BufsAndStrings\Desc\Pointer

The example shows the basic idea of pointer descriptors and how they are used.

Run the example either under WINS or on the ARMI platform

• TPtr: modifiable pointer descriptor, derived from TDes

• TPtrC: constant pointer descriptor, derived from TDesC

• TPtrC8: 8 bit constant pointer descriptor, derived from TDesC8

• TPtrC16: 16 bit constant pointer descriptor, derived from TDesC16