SimpleAdapter代码学习bindView

工作任务完成了，，闲来无事看看Android FrameWork层源码，SimpleAdater；

看到bindView（）这个方法有这么一段：

   boolean bound = false;      if (binder != null) {        bound = binder.setViewValue(v, data, text);   }

判断SimpleAdapte有没有指定SimpleAdapter.ViewBinder,如果指定了就调用其setViewValue方法, SimpleAdapter.ViewBinder是一个接口,也只有这一个方法,如果ViewBinder返回true表示我们已经完成了对这个View的数据绑定,就不再调用系统默认的实现；
嘿嘿，貌似以前复写SimpleAdapter,BaseAdapter的时候，都没有关注过这个。

 /**     * This class can be used by external clients of SimpleAdapter to bind     * values to views.     *     * You should use this class to bind values to views that are not     * directly supported by SimpleAdapter or to change the way binding     * occurs for views supported by SimpleAdapter.     *     * @see SimpleAdapter#setViewImage(ImageView, int)     * @see SimpleAdapter#setViewImage(ImageView, String)     * @see SimpleAdapter#setViewText(TextView, String)     */    public static interface ViewBinder {        /**         * Binds the specified data to the specified view.         *         * When binding is handled by this ViewBinder, this method must return true.         * If this method returns false, SimpleAdapter will attempts to handle         * the binding on its own.         *         * @param view the view to bind the data to         * @param data the data to bind to the view         * @param textRepresentation a safe String representation of the supplied data:         *        it is either the result of data.toString() or an empty String but it         *        is never null         *         * @return true if the data was bound to the view, false otherwise         */        boolean setViewValue(View view, Object data, String textRepresentation);    }

在这个 setViewValue中，我们可以做一些事情，可以在系统绑定数据之前做些事情，如：在Item中动态添加事件，或者添加删除view;再手动返回false或都true，控制是否再，由系统来默认实现；

 SimpleAdapter.ViewBinder binder = new SimpleAdapter.ViewBinder() {            @Override            public boolean setViewValue(View view, Object data, String textRepresentation) {                if (view instanceof Button) {                    final View button = view;                    LinearLayout listItem = (LinearLayout) button.getParent();                    TextView textView = new TextView(AdapterDemoActivity.this);                    textView.setText("AA");                    listItem.addView(textView,new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));                    return false;                }                return false;            }        };

adapter.setViewBinder(binder);