- Qt 6.4
- Qt Bluetooth
- C++ Classes
- QLowEnergyCharacteristicData
- Qt 6.4.3 Reference Documentation

# QLowEnergyCharacteristicData Class

The QLowEnergyCharacteristicData class is used to set up GATT service data. More...

Header: | #include <QLowEnergyCharacteristicData>
qmake: | QT += bluetooth
Since: | Qt 5.7

- List of all members, including inherited members

## Public Functions

| QLowEnergyCharacteristicData(const QLowEnergyCharacteristicData &other)
| QLowEnergyCharacteristicData()
QLowEnergyCharacteristicData & | operator=(const QLowEnergyCharacteristicData &other)
| ~QLowEnergyCharacteristicData()
void | addDescriptor(const QLowEnergyDescriptorData &descriptor)
QList<QLowEnergyDescriptorData> | descriptors() const
bool | isValid() const
int | maximumValueLength() const
int | minimumValueLength() const
QLowEnergyCharacteristic::PropertyTypes | properties() const
QBluetooth::AttAccessConstraints | readConstraints() const
void | setDescriptors(const QList<QLowEnergyDescriptorData> &descriptors)
void | setProperties(QLowEnergyCharacteristic::PropertyTypes properties)
void | setReadConstraints(QBluetooth::AttAccessConstraints constraints)
void | setUuid(const QBluetoothUuid &uuid)
void | setValue(const QByteArray &value)
void | setValueLength(int minimum, int maximum)
void | setWriteConstraints(QBluetooth::AttAccessConstraints constraints)
void | swap(QLowEnergyCharacteristicData &other)
QBluetoothUuid | uuid() const
QByteArray | value() const
QBluetooth::AttAccessConstraints | writeConstraints() const

## Related Non-Members

bool | operator!=(const QLowEnergyCharacteristicData &a, const QLowEnergyCharacteristicData &b)
bool | operator==(const QLowEnergyCharacteristicData &a, const QLowEnergyCharacteristicData &b)

## Detailed Description

An Object of this class provides a characteristic to be added to a QLowEnergyServiceData object via QLowEnergyServiceData::addCharacteristic().

See also QLowEnergyServiceData and QLowEnergyController::addService.

## Member Function Documentation

### QLowEnergyCharacteristicData::QLowEnergyCharacteristicData(const QLowEnergyCharacteristicData &other)

Constructs a new object of this class that is a copy of other.

### QLowEnergyCharacteristicData::QLowEnergyCharacteristicData()

Creates a new invalid object of this class.

### QLowEnergyCharacteristicData &QLowEnergyCharacteristicData::operator=(const QLowEnergyCharacteristicData &other)

Makes this object a copy of other and returns the new value of this object.

### QLowEnergyCharacteristicData::~QLowEnergyCharacteristicData()

Destroys this object.

### void QLowEnergyCharacteristicData::addDescriptor(const QLowEnergyDescriptorData &descriptor)

Adds descriptor to the list of descriptors of this characteristic, if it is valid.

See also setDescriptors().

### QList<QLowEnergyDescriptorData> QLowEnergyCharacteristicData::descriptors() const

Returns the descriptors of this characteristic.

See also setDescriptors().

### bool QLowEnergyCharacteristicData::isValid() const

Returns true if and only if this characteristic is valid, that is, it has a non-null UUID.

### int QLowEnergyCharacteristicData::maximumValueLength() const

Returns the maximum length in bytes that the value of this characteristic can have. By default, there is no limit beyond the constraints of the data type.

### int QLowEnergyCharacteristicData::minimumValueLength() const

Returns the minimum length in bytes that the value of this characteristic can have. The default is zero.

### QLowEnergyCharacteristic::PropertyTypes QLowEnergyCharacteristicData::properties() const

Returns the properties of this characteristic.

See also setProperties().

### QBluetooth::AttAccessConstraints QLowEnergyCharacteristicData::readConstraints() const

Returns the constraints needed for a client to read the value of this characteristic. If properties() does not include QLowEnergyCharacteristic::Read, this value is irrelevant. By default, there are no read constraints.

See also setReadConstraints().

### void QLowEnergyCharacteristicData::setDescriptors(const QList<QLowEnergyDescriptorData> &descriptors)

Sets the descriptors of this characteristic to descriptors. Only valid descriptors are considered.

See also descriptors() and addDescriptor().

### void QLowEnergyCharacteristicData::setProperties(QLowEnergyCharacteristic::PropertyTypes properties)

Sets the properties of this characteristic to properties.

See also properties().

### void QLowEnergyCharacteristicData::setReadConstraints(QBluetooth::AttAccessConstraints constraints)

Specifies that clients need to fulfill constraints to read the value of this characteristic.

See also readConstraints().

### void QLowEnergyCharacteristicData::setUuid(const QBluetoothUuid &uuid)

Sets the UUID of this characteristic to uuid.

See also uuid().

### void QLowEnergyCharacteristicData::setValue(const QByteArray &value)

Sets the value of this characteristic to value.

See also value().

### void QLowEnergyCharacteristicData::setValueLength(int minimum, int maximum)

Specifies minimum and maximum to be the smallest and largest length, respectively, that the value of this characteristic can have. The unit is bytes. If minimum and maximum are equal, the characteristic has a fixed-length value.

### void QLowEnergyCharacteristicData::setWriteConstraints(QBluetooth::AttAccessConstraints constraints)

Specifies that clients need to fulfill constraints to write the value of this characteristic.

See also writeConstraints().

### void QLowEnergyCharacteristicData::swap(QLowEnergyCharacteristicData &other)

Swaps this object with other.

### QBluetoothUuid QLowEnergyCharacteristicData::uuid() const

Returns the UUID of this characteristic.

See also setUuid().

### QByteArray QLowEnergyCharacteristicData::value() const

Returns the value of this characteristic.

See also setValue().

### QBluetooth::AttAccessConstraints QLowEnergyCharacteristicData::writeConstraints() const

Returns the constraints needed for a client to write the value of this characteristic. If properties() does not include either of QLowEnergyCharacteristic::Write, QLowEnergyCharacteristic::WriteNoResponse and QLowEnergyCharacteristic::WriteSigned, this value is irrelevant. By default, there are no write constraints.

See also setWriteConstraints().

## Related Non-Members

### bool operator!=(const QLowEnergyCharacteristicData &a, const QLowEnergyCharacteristicData &b)

Returns `true` if a and b are not equal with respect to their public state, otherwise returns `false`.

### bool operator==(const QLowEnergyCharacteristicData &a, const QLowEnergyCharacteristicData &b)

Returns `true` if a and b are equal with respect to their public state, otherwise returns `false`.