Question

When programming on Android, we use context object everywhere (maybe context keyword or this keyword), but I don’t really understand what its purpose.

For example, when we add UI Component such as TextView:

TextView textView = new TextView(this);  //this simple line make me headache
setContentView(textView);

The first time I think above line is : this keyword mean: this textView will be assign to current screen. But after that, I see that is a wrong thinking because line setContentView(textView) do what I think.

So, who can explain for me, what purpose when we declare context object in above example. (and others case, if you please, tell me more :D)

thanks 🙂

Answer 1

You will need the Context class is when creating a view dynamically in an activity. For example, you may want to dynamically create a TextView from code. To do so, you instantiate the TextView class. The constructor for the TextView class takes a Context object, and because the Activity class is a subclass of Context, you can use the this keyword to represent the Context object.