Call Activity method from adapter

user1602687 picture user1602687 · Aug 27, 2012 · Viewed 165.4k times · Source

Is it possible to call method that is defined in Activity from ListAdapter?

(I want to make a Button in list's row and when this button is clicked, it should perform the method, that is defined in corresponding Activity. I tried to set onClickListener in my ListAdapter but I don't know how to call this method, what's its path...)

when I used Activity.this.method() I get the following error:

No enclosing instance of the type Activity is accessible in scope

Any Idea ?

Answer

Eldhose M Babu picture Eldhose M Babu · Aug 27, 2012

Yes you can.

In the adapter Add a new Field :

private Context mContext;

In the adapter Constructor add the following code :

public AdapterName(......, Context context) {
  //your code.
  this.mContext = context;
}

In the getView(...) of Adapter:

Button btn = (Button) convertView.findViewById(yourButtonId);
btn.setOnClickListener(new Button.OnClickListener() {
  @Override
  public void onClick(View v) {
    if (mContext instanceof YourActivityName) {
      ((YourActivityName)mContext).yourDesiredMethod();
    }
  }
});

replace with your own class names where you see your code, your activity etc.

If you need to use this same adapter for more than one activity then :

Create an Interface

public interface IMethodCaller {
    void yourDesiredMethod();
}

Implement this interface in activities you require to have this method calling functionality.

Then in Adapter getView(), call like:

Button btn = (Button) convertView.findViewById(yourButtonId);
btn.setOnClickListener(new Button.OnClickListener() {
    @Override
    public void onClick(View v) {
        if (mContext instanceof IMethodCaller) {
            ((IMethodCaller) mContext).yourDesiredMethod();
        }
    }
});

You are done. If you need to use this adapter for activities which does not require this calling mechanism, the code will not execute (If check fails).