在首选项行中添加一个按钮

Question

I want a button in my Settings screen. This exact question has been asked here . But unfortunately has no answers. :(

In order to get to this, I created a custom preference like this -

  public class CustomPreference extends Preference {

    private LinearLayout mWidgetContainer;
    private View mRowView;

    public CustomPreference(Context context) {
        super(context);
    }

    public CustomPreference(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public CustomPreference(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
    }

    @Override
    protected View onCreateView(ViewGroup parent) {
        LayoutInflater viewInflater = (LayoutInflater) getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);

        mRowView = viewInflater.inflate(R.layout.preferences_row_view, parent, false);

        mWidgetContainer = (LinearLayout) mRowView.findViewById(android.R.id.widget_frame);

        Button button = new Button(getContext());
        LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);

        button.setLayoutParams(params);
        button.setBackgroundResource(R.drawable.listview_row_bg);
        button.setTextSize(14);
        button.setPadding(5, 5, 5, 5);
        button.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                Intent intent = new Intent(getContext(), BuyScreenActivity.class);
                getContext().startActivity(intent);
            }
        });
        button.setTypeface(null, Typeface.BOLD);
        button.setText("Buy now");
        mWidgetContainer.addView(button);

        return mRowView;
    }
}

This does work. But it behaves strange. As you can see on click of that button I'm taking the user to Activity called BuyScreenActivity . The strange part is when I press back on BuyScreenActivity , I come back to my Settings screen but onDestroy and onStop of BuyScreenActivity is not called at all. Why would it behave that way?

If I scroll down the settings screen, onStop & onDestroy will then be called. Why does this have to behave that way?

Answer 1

I don't know why that is happening exactly, but if it bothers you, just override onBackPressed() in BuyScreenActivity.java:

@Override
public void onBackPressed() {
    startActivity(new Intent(getContext(), SettingsACtivity.class));
}

Note that I'm assuming that you're only getting to BuyScreen through Settings. If you're not, then it's easy enough to put the name of the previous activity into the intent data, and switch that to get to the desired activity.