購物車實現

時間 2020-12-30

此文章實現的是購物車的demo，一些關於購物車的邏輯包括全選，單選，反選，父類選中子類聯動，子類選中父類聯動，都是一些比較簡單的一些功能，拿來expandlistview做的

首先是主頁的一個佈局文件

在這裏我們將這個二級列表拿出來將寬高又重新測量適配了一下，因爲下面的刷新工作會改變寬高帶來不好的用戶體驗，加上ScrollVieww是爲了能夠讓我們的二級列表滑動

附上expandlistview的自定義類

public class MyExpandListView extends ExpandableListView {

public MyExpandListView(Context context, AttributeSet attrs) {
super(context, attrs);
}

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
int i = MeasureSpec.makeMeasureSpec(Integer.MAX_VALUE >> 2, MeasureSpec.AT_MOST);
super.onMeasure(widthMeasureSpec, i);
}
}

下面是兩個佈局文件買一個是父條目的，另一個是子條目的。

然後給大家帶來主頁面實現的一些邏輯代碼，最關鍵的是一定要有bean類來記錄選中的狀態以及未選中的狀態，能夠及時刷新更新UI

public class MainActivity extends AppCompatActivity implements View.OnClickListener{

private MyExpandListView exlv;
private List<DataBeanlist.DataBean> databean = new ArrayList<>();
private MyAdapter adapter ;
private CheckBox checkbox;
private TextView tv_price;
private TextView tv_num;
private String addnum ;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

initView();
loadData();
}

private void loadData() {
String url = "http://120.27.23.105/product/getCarts?uid=" + 106;
HttpOkUntils.getHttpOkUntils(this).okHttpGet(url, new NetClickListener() {
@Override
public void Suesses(DataBeanlist baseBean) {

List<DataBeanlist.DataBean> data = baseBean.getData();
databean.addAll(data);
adapter = new MyAdapter();
exlv.setAdapter(adapter);
int count = exlv.getCount();
for (int i=0;i<count;i++){
exlv.expandGroup(i);
}
//去掉箭頭
exlv.setGroupIndicator(null);
exlv.setOnGroupClickListener(new ExpandableListView.OnGroupClickListener() {
@Override
public boolean onGroupClick(ExpandableListView expandableListView, View view, int i, long l) {
return true;
}
});

}

@Override
public void Error(DataBeanlist baseBean) {

}
});
}

private void initView() {

exlv = (MyExpandListView) findViewById(R.id.expandlistview);
checkbox = (CheckBox) findViewById(R.id.checkbox2);
checkbox.setOnClickListener(this);
tv_price = (TextView) findViewById(R.id.tv_price);
tv_num = (TextView) findViewById(R.id.tv_num);

}

@Override
public void onClick(View view) {
if(checkbox.isChecked()){
for (int i = 0 ; i < databean.size() ; i ++ ){
List<DataBeanlist.DataBean.ListBean> list = databean.get(i).getList();
databean.get(i).setGroupCheck(true);
for (int y = 0 ;y<list.size();y++){
list.get(y).setChildGroupCheck(true);
}
}
sum();
notifyDataSetChanged();
}else {
for (int i = 0 ; i < databean.size() ; i ++ ){
List<DataBeanlist.DataBean.ListBean> list = databean.get(i).getList();
databean.get(i).setGroupCheck(false);
for (int y = 0 ;y<list.size();y++){
list.get(y).setChildGroupCheck(false);
}
}
//計算
sum();
notifyDataSetChanged();
}
}

class MyAdapter extends BaseExpandableListAdapter{
@Override
public int getGroupCount() {
return databean.size();
}

@Override
public int getChildrenCount(int i) {
return databean.get(i).getList().size();
}

@Override
public Object getGroup(int i) {
return databean.get(i);
}

@Override
public Object getChild(int i, int i1) {
return databean.get(i).getList().get(i1);
}

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

@Override
public long getChildId(int i, int i1) {
return i1;
}

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

@Override
public View getGroupView(int i, boolean b, View view, ViewGroup viewGroup) {
View v = View.inflate(MainActivity.this,R.layout.group_layout,null);
CheckBox cb_group = v.findViewById(R.id.cb_group);
if(databean.get(i).isGroupCheck()){
cb_group.setChecked(true);
}else {
cb_group.setChecked(false);
}

TextView tv_group_title = v.findViewById(R.id.tv_group_title);
tv_group_title.setText(databean.get(i).getSellerName());
cb_group.setOnClickListener(new GroupClickLister(i,cb_group));

return v;
}

@Override
public View getChildView(final int i, final int i1, boolean b, View view, ViewGroup viewGroup) {
View v = View.inflate(MainActivity.this,R.layout.child_layout,null);
CheckBox cb_child = v.findViewById(R.id.cb_child);
if(databean.get(i).getList().get(i1).isChildGroupCheck()){
cb_child.setChecked(true);
}else {
cb_child.setChecked(false);
}
TextView tv_child_title = v.findViewById(R.id.tv_child_title);
tv_child_title.setText(databean.get(i).getList().get(i1).getTitle());
String[] split = databean.get(i).getList().get(i1).getImages().split("\\|");
ImageView image_child = v.findViewById(R.id.image_child);
TextView tv_price = v.findViewById(R.id.tv_child_price);
tv_price.setText("￥" + databean.get(i).getList().get(i1).getPrice());
ImageLoader.getInstance().displayImage(split[0],image_child);

cb_child.setOnClickListener(new ChildClickLister(i,i1,cb_child));
return v;
}

@Override
public boolean isChildSelectable(int i, int i1) {
return false;
}

}
class ChildClickLister implements View.OnClickListener{

private int i ;
private int i1;
private CheckBox cb_child ;

public ChildClickLister(int i, int i1, CheckBox cb_child) {
this.i1 = i1;
this.i = i;
this.cb_child = cb_child;
}

@Override
public void onClick(View view) {
if(cb_child.isChecked()){
databean.get(i).getList().get(i1).setChildGroupCheck(true);
}else {
databean.get(i).getList().get(i1).setChildGroupCheck(false);
}
//二級聯動一級狀態
setParentCheckFlag();
//判斷全選狀態
int num = 0 ;
for (int i = 0 ; i<databean.size();i++){
if(!databean.get(i).isGroupCheck()){
num++;
}
}
if(num==0){
checkbox.setChecked(true);
}else {
checkbox.setChecked(false);
}
//計算價格
sum();
}

private void setParentCheckFlag() {
DataBeanlist.DataBean dataBean = databean.get(i);
List<DataBeanlist.DataBean.ListBean> list = dataBean.getList();
for (int i = 0 ; i < list.size();i++){
if(!list.get(i).isChildGroupCheck()){
dataBean.setGroupCheck(false);
notifyDataSetChanged();
return;
}
if(i == list.size()-1){
dataBean.setGroupCheck(true);
notifyDataSetChanged();
return;
}
}
}
}
private void sum() {

int num = 0 ;
int price = 0 ;
for (DataBeanlist.DataBean dd : databean){
List<DataBeanlist.DataBean.ListBean> list = dd.getList();
for (DataBeanlist.DataBean.ListBean ddl : list){
if(ddl.isChildGroupCheck()){
//log測試輸出
Log.d("qq","ddl.getNum() = " + ddl.getNum());
num++;
price+=ddl.getPrice();
}
}
}
tv_num.setText("結算(" + num+")");
tv_price.setText(price+"");
}

class GroupClickLister implements View.OnClickListener{

private int i ;
CheckBox cb_group ;

public GroupClickLister(int i, CheckBox cb_group) {
this.i = i;
this.cb_group = cb_group;
}

@Override
public void onClick(View view) {
if(cb_group.isChecked()){
setCheck(true);
}else {
setCheck(false);
checkbox.setChecked(false);
}
notifyDataSetChanged();
}
public void setCheck(boolean check) {
DataBeanlist.DataBean dataBean = databean.get(i);
List<DataBeanlist.DataBean.ListBean> list = dataBean.getList();
//一級狀態
dataBean.setGroupCheck(check);
//二級狀態
for (DataBeanlist.DataBean.ListBean list1 : list){
list1.setChildGroupCheck(check);
}
int num = 0 ;
for (int i = 0 ; i<databean.size();i++){
if(!databean.get(i).isGroupCheck()){
num++;
}
}
if(num==0){
checkbox.setChecked(true);
}else {
checkbox.setChecked(false);
}
sum();
}
}
//刷新
public void notifyDataSetChanged(){
exlv.setAdapter(adapter);
int count = exlv.getCount();
for (int i=0;i<count;i++){
exlv.expandGroup(i);
}
exlv.setOnGroupClickListener(new ExpandableListView.OnGroupClickListener() {
@Override
public boolean onGroupClick(ExpandableListView expandableListView, View view, int i, long l) {
return true;
}
});
}
}

然後就是選中圖片的一個背景選擇器

圖片素材

希望大家多多指導！！！