今天的主题， 自定义组件ListPopWindow ，iOS中，这个效果是自带的。PopWindow可以说在项目里用的比较多的了，可能有n处要用到PopWindow，那么自定义一个PopWindow，到处来用更方便一些。

先看一下效果：

效果就是这样，看一下实现，其实也没多难，就是想开源出来供小伙伴们使用，如有不合理地方，希望大家多多指正。

1.自定义PopWindow

首先我们分析一下，这样的效果肯定是一个PopWindow嵌套着listview，而上面的title、和下面的cancel是两个文本框，实现起来也比较简单。然后我们在PopWindow中声明两个接口，用来回调cancel和item的点击事件

public interface  OnPopItemClickListener{
        void onPopItemClick(View view,int position);
    }

    public interface OnBottomTextviewClickListener{
        void onBottomClick();
    }

然后再设置一些PopWindow的一些属性

parentView = LayoutInflater.from(context).inflate(R.layout.list_popwindow,null);
        setContentView(parentView);
        lv = (ListView) parentView.findViewById(R.id.lv_popwindow);
        //设置弹出窗体的高
        this.setWidth(ViewGroup.LayoutParams.MATCH_PARENT);
        this.setHeight(ViewGroup.LayoutParams.MATCH_PARENT);
        //设置弹出窗体可点击
        this.setFocusable(true);
        //实例化一个ColorDrawable颜色为半透明
        ColorDrawable dw = new ColorDrawable(0xb0000000);
        //设置SelectPicPopupWindow弹出窗体的背景
        this.setBackgroundDrawable(dw);

看一下整体的代码吧：

/**
 * Created by Hankkin on 16/1/25.
 */
public class ListPopWindow extends PopupWindow{

    private Context context;        //上下文
    private View parentView;        //父视图
    private List<PopBean> dataList; //item数据源
    private OnPopItemClickListener listener;    //item点击接口
    private ListView lv;    //item列表视图
    private View viewTop;   //title视图   
    private String topText,bottomText;  //title文字，bottom文字
    private TextView tvTop,tvBottom;    //title文本，bottom文本
    private PopWindowAdapter adapter;   //适配器
    private OnBottomTextviewClickListener bottomListener;//底部点击接口


    public interface  OnPopItemClickListener{
        void onPopItemClick(View view,int position);
    }

    public interface OnBottomTextviewClickListener{
        void onBottomClick();
    }

    public ListPopWindow(Context context,OnPopItemClickListener listener,OnBottomTextviewClickListener bottomListener,
                         View parentView,List<PopBean> dataList,String bottomText,String topText){
        this.context = context;
        this.listener = listener;
        this.parentView = parentView;
        this.dataList = dataList;
        this.bottomListener = bottomListener;
        this.topText = topText;
        this.bottomText = bottomText;

        initViews();
    }


    private void initViews(){
        parentView = LayoutInflater.from(context).inflate(R.layout.list_popwindow,null);
        setContentView(parentView);
        lv = (ListView) parentView.findViewById(R.id.lv_popwindow);
        //设置弹出窗体的高
        this.setWidth(ViewGroup.LayoutParams.MATCH_PARENT);
        this.setHeight(ViewGroup.LayoutParams.MATCH_PARENT);
        //设置弹出窗体可点击
        this.setFocusable(true);
        //实例化一个ColorDrawable颜色为半透明
        ColorDrawable dw = new ColorDrawable(0xb0000000);
        //设置SelectPicPopupWindow弹出窗体的背景
        this.setBackgroundDrawable(dw);

        //view添加OnTouchListener监听判断获取触屏位置如果在布局外面则销毁弹出框
        parentView.setOnTouchListener(new View.OnTouchListener() {
            public boolean onTouch(View v, MotionEvent event) {
                int height = parentView.findViewById(R.id.ll_bottom).getTop();
                int y = (int) event.getY();
                if (event.getAction() == MotionEvent.ACTION_UP) {
                    if (y > height) {
                        dismiss();
                    }
                }
                return true;
            }
        });

        update();
        viewTop = parentView.findViewById(R.id.view_line1);
        tvBottom = (TextView) parentView.findViewById(R.id.tv_popwindow_bottom);
        tvTop = (TextView) parentView.findViewById(R.id.tv_popwindow_first);
        adapter = new PopWindowAdapter(context,dataList,false);
        lv.setAdapter(adapter);

        if (!TextUtils.isEmpty(topText)){
            tvTop.setVisibility(View.VISIBLE);
            tvTop.setText(topText);
            viewTop.setVisibility(View.VISIBLE);
        }
        else {
            tvTop.setVisibility(View.GONE);
            viewTop.setVisibility(View.GONE);
        }

        if (!TextUtils.isEmpty(bottomText)){
            tvBottom.setVisibility(View.VISIBLE);
            tvBottom.setText(bottomText);
        }
        else {
            tvBottom.setVisibility(View.GONE);
        }

        lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
                listener.onPopItemClick(view, i);
            }
        });

        tvBottom.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                bottomListener.onBottomClick();
            }
        });

    }

}

2.看一些item的bean

这里我就声明了title和图片的id

package com.hankkin.library;

/**
 * Created by Hankkin on 16/1/25.
 */
public class PopBean {
    private String title;
    private int icon_res;

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public int getIcon_res() {
        return icon_res;
    }

    public void setIcon_res(int icon_res) {
        this.icon_res = icon_res;
    }

    public PopBean(String title, int icon_res) {
        this.title = title;
        this.icon_res = icon_res;
    }
}

3.自定义adapter适配器

这里面可能要注意的就是item的背景设置，有的是上半部分圆角、有的是下半部分圆角，特殊处理一下

@Override
    public View getView(int i, View view, ViewGroup viewGroup) {
        ViewHolder holder;
        if (view == null) {
            view = inflater.inflate(R.layout.listview_popwindow_item, null);
            holder = new ViewHolder();
            holder.tv_name = (TextView) view.findViewById(R.id.tv_title);
            holder.v_line = (View) view.findViewById(R.id.v_line);
            view.setTag(holder);
        } else {
            holder = (ViewHolder) view.getTag();
        }

        holder.tv_name.setText(dataList.get(i).getTitle());


        if (dataList.size() - 1 == i) {
            holder.v_line.setVisibility(View.INVISIBLE);
            holder.tv_name.setBackground(context.getResources().getDrawable(R.drawable.selector_bottom_half));
        } else {
            holder.v_line.setVisibility(View.VISIBLE);
            holder.tv_name.setBackground(context.getResources().getDrawable(R.drawable.list_gray_item));
        }
        return view;
    }

最后看一下调用

Activity需要实现item接口（OnPopItemClickListener）和底部按钮接口（OnBottomTextviewClickListener）

public void show(View view){
        List<PopBean> pops = new ArrayList<>();
        for (int i=0;i<5;i++){
            PopBean pop = new PopBean("item"+i,0);
            pops.add(pop);
        }
        popWindow = new ListPopWindow(MainActivity.this,this,this,rl,pops,"cancel","title");
        popWindow.showAtLocation(rl, Gravity.CENTER| Gravity.BOTTOM,0,0);
    }