How to pass variable from Activity to Adapter

Question

I need to pass a variable from an Activity to a GridView Adapter. What I tried was:

Declaring a method inside the activity:

public int getPoints()
{
    return points;
}

The in the adapter I declared:

mainActivity sel= new mainActivity();

And finally I called the method using:

int myPoints = sel.getPoints();

But it always returns 0. What is wrong with the code?

Answer 1

1. Add argument to your adapter constructor
2. Pass your variable when instantiating adapter MyGridAdapter adapter = new MyGridAdapter(myVariable)

To update variable from your activity you can also create method in your adapter and call it adapter.updateMyVariable(newVariable);

Answer 2

在mainActivity中创建公共静态变量点，然后从适配器mainActivity.points中调用。