回调函数

回调的使用在android 源码里面不少见：

这里截取了View类源码的一部分关于回调的使用：

    /**
     * Listener used to dispatch click events.
     * This field should be made private, so it is hidden from the SDK.
     * {@hide}
     */
    protected OnClickListener mOnClickListener;

    /**
     * Register a callback to be invoked when this view is clicked. If this view is not
     * clickable, it becomes clickable.
     *
     * @param l The callback that will run
     *
     * @see #setClickable(boolean)
     */
    public void setOnClickListener(OnClickListener l) {
        if (!isClickable()) {
            setClickable( true);
        }
        mOnClickListener = l;
    }

    /**
     * Interface definition for a callback to be invoked when a view is clicked.
     */
    public interface OnClickListener {
        /**
         * Called when a view has been clicked.
         *
         * @param v The view that was clicked.
         */
        void onClick(View v);
    }

		searchFilter_btn.setOnClickListener(new View.OnClickListener() {

			@Override
			public void onClick(View v) {
				
                      //处理部分
				
			}
		});