I am new to flutter and i want to use this code from a youtube tutorial

class _DeviceWithAvailability extends BluetoothDevice {
  BluetoothDevice device;
  _DeviceAvailability availability;
  int? rssi;

  _DeviceWithAvailability(this.device, this.availability, [this.rssi]);
}

but it giving an error

The superclass 'BluetoothDevice ' doesn't have a zero argument constructor.

and suggestion

Try declaring a zero argument constructor in 'BluetoothDevice ', or explicitly invoking a different constructor in 'BluetoothDevice '.

I read the documentation but it isn't clear to me.

Please help mo to solve this.

CodePudding user response：

The problem is in your BluetoothDevice device initialization, because the constructor need many parameters that are mandatory, you have two solutions.

1.Initializate this variable with empty parameters like this:

BluetoothDevice device = BluetoothDevice(...);

2.Add late property and before use this var do you need to initialize with correct information, like this:

late BluetoothDevice device;

and then, before use this var you need to pass the correct information like this:

device = BluetoothDevice(...);

CodePudding user response：

Your suggestion means,

A zero-argument constructor is literally a constructor that can be invoked with zero arguments. This includes constructors that take only optional arguments.

Some examples:

SomeClass();//this is zero argument constructor
SomeClass2(String argument1);//this is one argument constructor
SomeClass3(String argument1,String argument2);//this is 2 argument constructor