Get Activity Context in an Adapter from a Fragment

Question

I have a Fragment with a ListView. In the adapter I want to create a dialog.

class ViewHolder {
...
  @Override
  public void onClick(View v) {
    ...
    AlertDialog.Builder builder = new AlertDialog.Builder(mContext);
    ...
   }
...
}

mContext is the Context from my Fragment, which I save global when the adapter is created. I get the error.

unable to add window -- token null is not for an application

The method getActivity() is not available so how to get the Context of my Activity?

Answer 1

If you have a custom adapter, change the constructor to require Context as a parameter.

public CustomAdapter(Context context, List<Item> items) {   
}

Then, create an Instance variable to store the context via the constructor.

private Context mContext; //instance variable

public CustomAdapter(Context context, List<Item> items) {
    //some code
    this.mContext= context;
}

And now you can use the variable mContext from anywhere in your adapter.

To create the adapter, simply pass 'this' if created from an activity, or getActivity() if created from a fragment.

mAdapter = new CustomAdapter(this, mArrayItems);

Hope that helps.

Answer 2

When you are creating your adapter, what are you passing as a context? Try to pass this if you are not doing it. Some more code would be helpful too.