京东0729购物车

最新推荐文章于 2022-04-27 15:37:38 发布

原创最新推荐文章于 2022-04-27 15:37:38 发布 · 240 阅读

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本文介绍了一种自定义UI组件的方法，包括解决滑动冲突的ScrollView、自定义的加减控件MyNumLayout及自定义的ExpandableListView，并实现了一个用于购物车展示的二级列表适配器。

布局:

需要三个自定义: 1.2为的是解决滑动冲突 3.为自定义的加减框

1. ExpandableListView--自定义二级列表

public class MyExpandableListView extends ExpandableListView {
    public MyExpandableListView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        // TODO Auto-generated method stub
        int expandSpec = MeasureSpec.makeMeasureSpec(Integer.MAX_VALUE >> 2,
                MeasureSpec.AT_MOST);

        super.onMeasure(widthMeasureSpec, expandSpec);
    }
}

2.ScrollView--自定义滑动组件

public class MyScrollView extends ScrollView {
    private int downX, downY;
    private int mTouchSlop;

    public MyScrollView(Context context) {
        this(context, null);
    }

    public MyScrollView(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public MyScrollView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        mTouchSlop = ViewConfiguration.get(context).getScaledTouchSlop();
    }

    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
    public MyScrollView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
        super(context, attrs, defStyleAttr, defStyleRes);
        mTouchSlop = ViewConfiguration.get(context).getScaledTouchSlop();
    }

    @Override
    public boolean onInterceptTouchEvent(MotionEvent ev) {
        int action = ev.getAction();
        switch (action) {
            case MotionEvent.ACTION_DOWN:
                downX = (int) ev.getRawX();
                downY = (int) ev.getRawY();
                break;
            case MotionEvent.ACTION_MOVE:
                int moveY = (int) ev.getRawY();
                // 判断是否滑动，若滑动就拦截事件
                if (Math.abs(moveY - downY) > mTouchSlop) {
                    return true;
                }
                break;
            default:
                break;
        }

        return super.onInterceptTouchEvent(ev);
    }

}

3.MyNumLayout--继承自LinearLayout 一个自定义的加减控件

public class MyNumLayout extends LinearLayout implements View.OnClickListener {

    private TextView numLost;
    private TextView numShow;
    private TextView numAdd;

    public MyNumLayout(Context context) {
        this(context, null);
    }

    public MyNumLayout(Context context, @Nullable AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public MyNumLayout(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        //加载视图
        View view = View.inflate(context, R.layout.number_layout, this);
        numLost = view.findViewById(R.id.num_lost);
        numShow = view.findViewById(R.id.num_show);
        numAdd = view.findViewById(R.id.num_add);
        //加监听
        numLost.setOnClickListener(this);
        numAdd.setOnClickListener(this);

    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.num_lost:
                String s = numShow.getText().toString();
                int i = Integer.parseInt(s);
                i--;
                if(i >= 0){
                    setNumShow(i+"");
                    listener.changeTransaction(s);
                }
                break;
            case R.id.num_add:
                String s2 = numShow.getText().toString();
                int i2 = Integer.parseInt(s2);
                i2++;
                setNumShow(i2+"");
                listener.changeTransaction(s2);
                break;
        }
    }

    //暴露的设置和改变的num值方法
    public void setNumShow(String s) {
        numShow.setText(s);
    }

    public String getNumShow() {
        return numShow.getText().toString();
    }


    //搞一个加减的监听,数量也随之改变的回调接口
    private ChangeNumListener listener;
    public interface ChangeNumListener{
        void changeTransaction(String tnum);
    }
    public void setListener(ChangeNumListener listener) {
        this.listener = listener;
    }
}

适配器:

二级列表的适配器

public class MyExListAdapter extends BaseExpandableListAdapter {

    private Context context;
    private List<CartBean.DataBean> list;

    public MyExListAdapter(Context context, List<CartBean.DataBean> list) {
        this.context = context;
        this.list = list;
    }

    @Override
    public int getGroupCount() {
        return list.size();
    }

    @Override
    public int getChildrenCount(int groupPosition) {
        return list.get(groupPosition).getList().size();
    }

    @Override
    public Object getGroup(int groupPosition) {
        return list.get(groupPosition);
    }

    @Override
    public Object getChild(int groupPosition, int childPosition) {
        return list.get(groupPosition).getList().get(childPosition);
    }

    @Override
    public long getGroupId(int groupPosition) {
        return groupPosition;
    }

    @Override
    public long getChildId(int groupPosition, int childPosition) {
        return childPosition;
    }

    @Override
    public boolean hasStableIds() {
        return true;
    }


    @Override
    public boolean isChildSelectable(int groupPosition, int childPosition) {
        return true;
    }


    //容器
    static class GroupHolder{
        public TextView textName;
    }
    static class ChildHolder{
        public TextView TextTitle;
        public TextView TextPrice;
        public ImageView imageInfo;
        public CheckBox checkInfo;
        public MyNumLayout numLayout;

    }

    @Override
    public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {
        GroupHolder holder = null;
        if(convertView == null){
            convertView = View.inflate(context,R.layout.group_item,null);
            holder = new GroupHolder();
            holder.textName = convertView.findViewById(R.id.text_name);
            convertView.setTag(holder);
        }else{
            holder = (GroupHolder) convertView.getTag();
        }
        holder.textName.setText(list.get(groupPosition).getSellerName());
        return convertView;
    }

    @Override
    public View getChildView(final int groupPosition, final int childPosition, boolean isLastChild, View convertView, ViewGroup parent) {
        ChildHolder holder = null;
        if(convertView == null){
            convertView = View.inflate(context,R.layout.child_item,null);
            holder = new ChildHolder();
            holder.TextTitle = convertView.findViewById(R.id.text_title);
            holder.TextPrice = convertView.findViewById(R.id.text_price);
            holder.imageInfo = convertView.findViewById(R.id.image_info);
            holder.numLayout = convertView.findViewById(R.id.num_layout);//加减控件
            holder.checkInfo = convertView.findViewById(R.id.check_info);//多选框
            convertView.setTag(holder);
        }else{
            holder = (ChildHolder) convertView.getTag();
        }
        final String num = list.get(groupPosition).getList().get(childPosition).getNum();
        final String price = list.get(groupPosition).getList().get(childPosition).getPrice();
        boolean checkState = list.get(groupPosition).getList().get(childPosition).isCheckState();

        holder.TextPrice.setText("$"+ price);
        holder.numLayout.setNumShow(num);
        holder.TextTitle.setText(list.get(groupPosition).getList().get(childPosition).getTitle());
        Glide.with(context).load(list.get(groupPosition).getList().get(childPosition).getImages().split("\\|")[0]).into(holder.imageInfo);
        holder.checkInfo.setChecked(checkState);


        //判断起始状态
        boolean firstFlag = false;
        if(checkState){
            sumPrice(price,num,checkState);
            firstFlag = true;
        }else if(firstFlag){
            sumPrice(price,num,checkState);
            firstFlag = false;
        }



        //选中条目进算总价
        final ChildHolder finalHolder = holder;
        holder.checkInfo.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                checkedState = finalHolder.checkInfo.isChecked();
                sumPrice(price,num,checkedState);
            }
        });


        //点击加减的监听
        final ChildHolder finalHolder1 = holder;
        holder.numLayout.setListener(new MyNumLayout.ChangeNumListener() {
            @Override
            public void changeTransaction(String tnum) {
                String numShow = finalHolder1.numLayout.getNumShow();
                if(checkedState) {
                    sumPrice(price, tnum, checkedState);
                }
            }
        });



        return convertView;
    }

    private double sum = 0 ;//记录总价
    private int count = 0 ; //记录选中多选框的数量
    private boolean checkedState = false;//记录选中状态

    //计算总价
    public void sumPrice(String num, String price, boolean checked) {
        if (checked){
            sum += Double.parseDouble(num) * Double.parseDouble(price);
        }else{
            sum -= Double.parseDouble(num) * Double.parseDouble(price);
        }
        onSumListener.takeSumPrice(sum);
    }


    //回调总价接口
    private OnSumListener onSumListener;
    public interface OnSumListener{
        void takeSumPrice(double sum);
    }

    public void setOnSumListener(OnSumListener onSumListener) {
        this.onSumListener = onSumListener;
    }

}//end