#include <e32des8.h>
Link against:
euser.lib
class TDesC8;
Description
Abstract base class for 8-bit non-modifiable descriptors.
The class encapsulates the data member containing the length of data represented by an 8-bit descriptor. It also provides
member functions through which the data can be accessed, but not modified.
Data represented by this class is treated as a contiguous set of 8-bit (i.e. single byte) values or data items.
This class cannot be instantiated as it is intended to form part of a class hierarchy; it provides a well defined part of
descriptor behaviour. It can, however, be passed as an argument type for functions which want access to descriptor data but
do not need to modify that data.
Members
Defined in TDesC8:
Construction and destruction
protected: inline TDesC8(TInt aType, TInt aLength);
Description
Parameters
protected: inline TDesC8();
Description
operator<(const TDesC8 &)const
inline TBool operator<(const TDesC8 &aDes) const;
Description
Determines whether this descriptor's data is less than the specified descriptor's data.
The comparison is implemented using the TDesC8::Compare(const TDesC8 &)const member function.
Parameters
const TDesC8 &aDes |
The 8-bit non-modifable descriptor whose data is to be compared with this descriptor's data.
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Return value
TBool
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True if greater than or equal, false otherwise.
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See also:
operator<=(const TDesC8 &)const
inline TBool operator<=(const TDesC8 &aDes) const;
Description
Determines whether this descriptor's data is less than or equal to the specified descriptor's data.
The comparison is implemented using the TDesC8::Compare(const TDesC8 &)const member function.
Parameters
const TDesC8 &aDes |
The 8-bit non-modifable descriptor whose data is to be compared with this descriptor's data.
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Return value
TBool
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True if less than or equal, false otherwise.
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See also:
operator>(const TDesC8 &)const
inline TBool operator>(const TDesC8 &aDes) const;
Description
Determines whether this descriptor's data is greater than the specified descriptor's data.
The comparison is implemented using the TDesC8::Compare(const TDesC8 &)const member function.
Parameters
const TDesC8 &aDes |
The 8-bit non-modifable descriptor whose data is to be compared with this descriptor's data.
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Return value
TBool
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True if greater than, false otherwise.
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See also:
operator>=(const TDesC8 &)const
inline TBool operator>=(const TDesC8 &aDes) const;
Description
Determines whether this descriptor's data is greater than or equal to the specified descriptor's data.
The comparison is implemented using the TDesC8::Compare(const TDesC8 &)const member function.
Parameters
const TDesC8 &aDes |
The 8-bit non-modifable descriptor whose data is to be compared with this descriptor's data.
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Return value
TBool
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True if greater than, false otherwise.
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See also:
operator==(const TDesC8 &)const
inline TBool operator==(const TDesC8 &aDes) const;
Description
Determines whether this descriptor's data is equal to the specified descriptor's data.
The comparison is implemented using the TDesC8::Compare(const TDesC8 &)const member function.
Parameters
const TDesC8 &aDes |
The 8-bit non-modifable descriptor whose data is to be compared with this descriptor's data.
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Return value
TBool
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True if equal, false otherwise.
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See also:
operator!=(const TDesC8 &)const
inline TBool operator!=(const TDesC8 &aDes) const;
Description
Determines whether this descriptor's data is not equal to the specified descriptor's data.
The comparison is implemented using the TDesC8::Compare(const TDesC8 &)const member function.
Parameters
const TDesC8 &aDes |
The 8-bit non-modifable descriptor whose data is to be compared with this descriptor's data.
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Return value
TBool
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True if not equal, false otherwise.
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See also:
inline const TUint8& operator[](TInt anIndex) const;
Description
Gets a reference to a single data item within this descriptor's data.
Parameters
TInt anIndex |
The position of the individual data item within the descriptor's data. This is an offset value; a zero value refers to the
leftmost data position.
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Return value
const TUint8 & |
A reference to the data item.
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Panic codes
USER |
21, if anIndex is negative or greater than or equal to the current length of the descriptor.
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inline TInt Length() const;
Description
Gets the length of the data.
This is the number of 8-bit values or data items represented by the descriptor.
Return value
TInt
|
The length of the data represented by the descriptor.
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inline TInt Size() const;
Description
Gets the size of the data.
This is the number of bytes occupied by the data represented by the descriptor.
Return value
TInt
|
The size of the data represented by the descriptor.
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IMPORT_C const TUint8* Ptr() const;
Description
Gets a pointer to the data represented by the descriptor.
The data cannot be changed through the returned pointer.
Return value
const TUint8 * |
A pointer to the data
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Compare(const TDesC8 &)const
IMPORT_C TInt Compare(const TDesC8 &aDes) const;
Description
Compares this descriptor's data with the specified descriptor's data.
The comparison proceeds on a byte for byte basis. The result of the comparison is based on the difference of the first bytes
to disagree.
Two descriptors are equal if they have the same length and content. Where two descriptors have different lengths and the shorter
descriptor's data matches the first part of the longer descriptor's data, the shorter is considered to be less than the longer.
Parameters
const TDesC8 &aDes |
The 8-bit non-modifable descriptor whose data is to be compared with this descriptor's data.
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Return value
TInt
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Positive, if this descriptor is greater than the specified descriptor. Negative, if this descriptor is less than the specified
descriptor. Zero, if both descriptors have the same length and the their contents are the same.
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Match(const TDesC8 &)const
IMPORT_C TInt Match(const TDesC8 &aDes) const;
Description
Searches this descriptor's data for a match with the match pattern supplied in the specified descriptor.
The match pattern can contain the wildcard characters "*" and "?", where "*" matches zero or more consecutive occurrences
of any character and "?" matches a single occurrence of any character.
Note that there is no 'escape character', which means that it is not possible to match either the "*" character itself or
the "?" character itself using this function.
Parameters
const TDesC8 &aDes |
An 8-bit non-modifable descriptor containing the match pattern.
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Return value
TInt
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If a match is found, the offset within this descriptor's data where the match first occurs. KErrNotFound, if there is no match.
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MatchF(const TDesC8 &)const
IMPORT_C TInt MatchF(const TDesC8 &aDes) const;
Description
Searches this descriptor's folded data for a match with the folded match pattern supplied in the specified descriptor.
The match pattern can contain the wildcard characters "*" and "?", where "*" matches zero or more consecutive occurrences
of any character and "?" matches a single occurrence of any character.
Note that folding is locale-independent behaviour. It is also important to note that there can be no guarantee that folding
is in any way culturally appropriate, and should not be used for matching strings in natural language; use TDesC8::MatchC(const TDesC8 &)const for this.
Note that there is no 'escape character', which means that it is not possible to match either the "*" character itself or
the "?" character itself using this function.
Parameters
const TDesC8 &aDes |
An 8-bit non-modifable descriptor containing the match pattern.
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Return value
TInt
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If a match is found, the offset within this descriptor's data where the match first occurs. KErrNotFound, if there is no match.
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See also:
MatchC(const TDesC8 &)const
| Interface status: |
deprecated |
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IMPORT_C TInt MatchC(const TDesC8 &aDes) const;
Description
Searches this descriptor's collated data for a match with the collated match pattern supplied in the specified descriptor.
The function uses the standard collation method for narrow text appropriate to the current locale.
The match pattern can contain the wildcard characters "*" and "?", where "*" matches zero or more consecutive occurrences
of any character and "?" matches a single occurrence of any character.
Note that there is no 'escape character', which means that it is not possible to match either the "*" character itself or
the "?" character itself using this function.
Parameters
const TDesC8 &aDes |
An 8-bit non-modifable descriptor containing the match pattern.
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Return value
TInt
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If a match is found, the offset within this descriptor's data where the match first occurs. KErrNotFound, if there is no match.
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IMPORT_C TInt Locate(TChar aChar) const;
Description
Searches for the first occurrence of a character within this descriptor's data.
The search starts at the beginning of the data, i.e. at the leftmost position.
Parameters
TChar aChar |
The character to be found.
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Return value
TInt
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The offset of the character position from the beginning of the data. KErrNotFound, if no matching character can be found.
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LocateReverse(TChar)const
IMPORT_C TInt LocateReverse(TChar aChar) const;
Description
Searches for the first occurrence of a character within this descriptor's data, searching from the end of the data.
The search starts at the rightmost position.
Parameters
TChar aChar |
The character to be found.
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Return value
TInt
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The offset of the character position from the beginning of the data. KErrNotFound, if no matching character can be found.
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Find(const TDesC8 &)const
IMPORT_C TInt Find(const TDesC8 &aDes) const;
Description
Searches for the first occurrence of the specified data sequence within this descriptor.
Searching always starts at the beginning of this descriptor's data.
Parameters
const TDesC8 &aDes |
The 8-bit non modifable descriptor containing the data sequence to be searched for.
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Return value
TInt
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The offset of the data sequence from the beginning of this descriptor's data. KErrNotFound, if the data sequence cannot be
found.
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Find(const TUint8 *,TInt)const
IMPORT_C TInt Find(const TUint8 *pS, TInt aLenS) const;
Description
Searches for the first occurrence of the specified data sequence within this descriptor.
Searching always starts at the beginning of this descriptor's data.
Parameters
const TUint8 *pS |
A pointer to a location containing the data sequence to be searched for.
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TInt aLenS |
The length of the data sequence to be searched for. This value must not be negative, otherwise the function raises a panic.
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Return value
TInt
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The offset of the data sequence from the beginning of this descriptor's data. KErrNotFound, if the data sequence cannot be
found.
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Panic codes
USER |
29 if aLenS is negative.
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IMPORT_C TPtrC8 Left(TInt aLength) const;
Description
Extracts the leftmost part of the data.
The function does not cut or remove any data but constructs a non-modifiable pointer descriptor to represent the leftmost
part of the data.
Parameters
TInt aLength |
The length of the data to be extracted. If this value is greater than the length of the descriptor, the function extracts
the whole of the descriptor.
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Return value
TPtrC8
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The 8-bit non-modifiable pointer descriptor representing the leftmost part of the data.
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Panic codes
USER |
22 if aLength is negative.
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IMPORT_C TPtrC8 Right(TInt aLength) const;
Description
Extracts the rightmost part of the data.
The function does not cut or remove any data but constructs a non-modifiable pointer descriptor to represent the rightmost
part of the data.
Parameters
TInt aLength |
The length of data to be extracted. If this value is greater than the length of the descriptor, the function extracts the
whole of the descriptor.
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Return value
TPtrC8
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The 8 bit non-modifiable pointer descriptor representing the rightmost part of the data.
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Panic codes
USER |
22 if aLength is negative.
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IMPORT_C TPtrC8 Mid(TInt aPos) const;
Description
Extracts a portion of the data.
The function does not cut or remove any data but constructs a non-modifiable pointer descriptor to represent the defined portion.
The portion is identified by its starting position and by the length of the remainder of the data starting from the specified
position.
Parameters
TInt aPos |
The starting position of the data to be extracted. This is an offset value; a zero value refers to the leftmost data position.
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Return value
TPtrC8
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The 8-bit non-modifiable pointer descriptor representing the specified portion of the data.
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Panic codes
USER |
22 if aPos is negative or aPos is greater than the length of the descriptor.
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IMPORT_C TPtrC8 Mid(TInt aPos, TInt aLength) const;
Description
Extracts a portion of the data.
The function does not cut or remove any data but constructs a non-modifiable pointer descriptor to represent the defined portion.
The portion is identified by its starting position and by its length.
Parameters
TInt aPos |
The starting position of the data to be extracted. This is an offset value; a zero value refers to the leftmost data position.
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TInt aLength |
The length of data to be extracted.
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Return value
TPtrC8
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The 8 bit non-modifiable pointer descriptor representing the specified portion of the data.
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Panic codes
USER |
22 if aPos is negative or aPos plus aLength is greater than the length of the descriptor.
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CompareF(const TDesC8 &)const
IMPORT_C TInt CompareF(const TDesC8 &aDes) const;
Description
Compares this descriptor's folded data with the specified descriptor's folded data.
Note that folding is locale-independent behaviour. It is also important to note that there can be no guarantee that folding
is in any way culturally appropriate, and should not be used for comparing strings in natural language; use TDesC8::CompareC(const TDesC8 &)const for this.
Parameters
const TDesC8 &aDes |
The 8-bit non modifable descriptor whose data is to be compared with this descriptor's data.
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Return value
TInt
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Positive, if this descriptor is greater than the specified descriptor. Negative, if this descriptor is less than the specified
descriptor. Zero, if both descriptors have the same length and the their contents are the same.
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See also:
CompareC(const TDesC8 &)const
| Interface status: |
deprecated |
|
IMPORT_C TInt CompareC(const TDesC8 &aDes) const;
Description
Compares this descriptor's data with the specified descriptor's data using the standard collation method for narrow text appropriate
to the current locale.
Parameters
const TDesC8 &aDes |
The 8-bit non modifable descriptor whose data is to be compared with this descriptor's data.
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Return value
TInt
|
Positive, if this descriptor is greater than the specified descriptor. Negative, if this descriptor is less than the specified
descriptor. Zero, if both descriptors have the same length and the their contents are the same.
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See also:
IMPORT_C TInt LocateF(TChar aChar) const;
Description
Searches for the first occurrence of a folded character within this descriptor's folded data.
The search starts at the beginning of the data,i.e. at the leftmost position.
Note that folding is locale-independent behaviour. It is also important to note that there can be no guarantee that folding
is in any way culturally appropriate, and should not be used for searching strings in natural language.
Parameters
TChar aChar |
The character to be found.
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Return value
TInt
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The offset of the character position from the beginning of the data. KErrNotFound, if no matching character can be found.
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LocateReverseF(TChar)const
IMPORT_C TInt LocateReverseF(TChar aChar) const;
Description
Searches for the first occurrence of a folded character within this descriptor's folded data, searching from the end of the
data.
The search starts at the rightmost position.
Note that folding is locale-independent behaviour. It is also important to note that there can be no guarantee that folding
is in any way culturally appropriate, and should not be used for searching strings in natural language.
Parameters
TChar aChar |
The character to be found
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Return value
TInt
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The offset of the character position from the beginning of the data. KErrNotFound, if no matching character can be found
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FindF(const TDesC8 &)const
IMPORT_C TInt FindF(const TDesC8 &aDes) const;
Description
Searches for the first occurrence of the specified folded data sequence within this descriptor's folded data.
Searching always starts at the beginning of this descriptor's data.
Note that folding is locale-independent behaviour. It is also important to note that there can be no guarantee that folding
is in any way culturally appropriate, and should not be used for finding strings in natural language; use TDesC8::FindC(const TDesC8 &)const for this.
Parameters
const TDesC8 &aDes |
The 8-bit non-modifable descriptor containing the data sequence to be searched for.
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Return value
TInt
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The offset of the data sequence from the beginning of this descriptor's data. KErrNotFound, if the data sequence cannot be
found. Zero, if the length of the search data sequence is zero.
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See also:
FindF(const TUint8 *,TInt)const
IMPORT_C TInt FindF(const TUint8 *pS, TInt aLenS) const;
Description
Searches for the first occurrence of the specified folded data sequence within this descriptor's folded data.
Searching always starts at the beginning of this descriptor's data.
Note that folding is locale-independent behaviour. It is also important to note that there can be no guarantee that folding
is in any way culturally appropriate, and should not be used for finding strings in natural language; use TDesC8::FindC(const TDesC8 &)const for this.
Parameters
const TUint8 *pS |
A pointer to a location containing the data sequence to be searched for.
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TInt aLenS |
The length of the data sequence to be searched for. This value must not be negative, otherwise the function raises a panic.
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Return value
TInt
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The offset of the data sequence from the beginning of this descriptor's data. KErrNotFound, if the data sequence cannot be
found. Zero, if the length of the search data sequence is zero.
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Panic codes
USER |
29 if aLenS is negative
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See also:
FindC(const TDesC8 &)const
| Interface status: |
deprecated |
|
IMPORT_C TInt FindC(const TDesC8 &aDes) const;
Description
Searches for the first occurrence of the specified collated data sequence within this descriptor's collated data.
Searching always starts at the beginning of this descriptor's data. The function uses the standard collation method for narrow
text appropriate to the current locale.
Parameters
const TDesC8 &aDes |
The 8-bit non-modifable descriptor containing the data sequence to be searched for.
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Return value
TInt
|
The offset of the data sequence from the beginning of this descriptor's data. KErrNotFound, if the data sequence cannot be
found.
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FindC(const TUint8 *,TInt)const
| Interface status: |
deprecated |
|
IMPORT_C TInt FindC(const TUint8 *pS, TInt aLenS) const;
Description
Searches for the first occurrence of the specified collated data sequence within this descriptor's collated data.
Searching always starts at the beginning of this descriptor's data. The function uses the standard collation method for narrow
text appropriate to the current locale.
Parameters
const TUint8 *pS |
A pointer to a location containing the data sequence to be searched for.
|
TInt aLenS |
The length of the data sequence to be searched for.
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Return value
TInt
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The offset of the data sequence from the beginning of this descriptor's data. KErrNotFound, if the data sequence cannot be
found.
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Panic codes
USER |
29 if aLength is negative.
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IMPORT_C HBufC8* Alloc() const;
Description
Creates a new 8-bit heap descriptor and initialises it with a copy of this descriptor's data.
Return value
HBufC8 * |
A pointer to the new 8 bit heap descriptor, if creation is successful. NULL, if creation of the descriptor fails.
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IMPORT_C HBufC8* AllocL() const;
Description
Creates a new 8-bit heap descriptor and initialises it with a copy of this descriptor's data.
The function leaves, if creation of the descriptor fails.
Return value
HBufC8 * |
A pointer to the 8-bit heap descriptor, if creation is successful.
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IMPORT_C HBufC8* AllocLC() const;
Description
Creates a new 8-bit heap descriptor, initialises it with a copy of this descriptor's data, and puts a pointer to the descriptor
onto the cleanup stack.
The function leaves, if creation of the descriptor fails.
Return value
HBufC8 * |
A pointer to the 8 bit heap descriptor, if creation is successful. The pointer is also put onto the cleanup stack.
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protected: inline TInt Type() const;
Description
Return value
protected: inline void DoSetLength(TInt aLength);
Description
Parameters
protected: IMPORT_C const TUint8& AtC(TInt anIndex) const;
Description
Parameters
Return value
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