Android添加书签(二)(3)

        bottomButton = (ImageButton) findViewById(R.id.bottombutton); 
 
        upButton.setOnClickListener(this); 
        downButton.setOnClickListener(this); 
        deleteButton.setOnClickListener(this); 
        launchButton.setOnClickListener(this); 
        topButton.setOnClickListener(this); 
        bottomButton.setOnClickListener(this); 
 
        // if we have some bookmarks select the first and start everything 
        if (bookmarkAdapter.getCount() > 0) { 
            bookmarkAdapter.initialiseAllRows(); 
            currentPos = 0; 
            bookmarkAdapter.setSelected(currentPos); 
        } 
 
        // Make sure the welcome message only appears on first launch 
        SharedPreferences settings = getSharedPreferences(PREFS_NAME, 0); 
        if (settings != null) { 
            boolean launchedPreviously = settings.getBoolean(LAUNCHED_KEY, 
                    false); 
            if (!launchedPreviously) { 
                showDialog(DIALOG_WELCOME); 
                SharedPreferences.Editor editor = settings.edit(); 
                editor.putBoolean(LAUNCHED_KEY, true); 
                editor.commit(); 
            } 
        } 
    } 
 
    /**
     * Invoked during init to give the Activity a chance to set up its Menu.
     * 
     * @param menu
     *            the Menu to which entries may be added