硅谷商城5--购物车商品选中和商品总价计算

adapter = new GovaffairPagerAdapter(context,datas,checkbox_all,tv_total_price);

/**
* 显示总商品价格
*/
private void showTotalPrice(){
tv_total_price.setText("合计￥"+getTotalPrice());
}

/**
* 计算购物车里面所选商品总架构
* @return
*/
private double getTotalPrice(){
double num = 0;
if(datas != null && datas.size() >0){
for(int i=0;i<datas.size();i++){
ShoppingCart cart = datas.get(i);
//判断是否选中的商品
if(cart.isChecked()){
num = num + cart.getPrice()*cart.getCount();
}
}
}
return num;
}

//在构造方法中调用
public GovaffairPagerAdapter(final Context context, final List<ShopingCart> datas) {
this.context = context;
this.datas = datas;
cartProvider = new CartProvider(context);
showTotalPrice();
}

@Override
public void onBindViewHolder(ViewHolder holder, int position) {
final ShoppingCart cart = datas.get(position);
......

holder.numberAddSubView.setOnButtonClickListenter(new NumberAddSubView.OnButtonClickListenter() {

@Override
public void onButtonAddClick(View view, int value) {
cart.setCount(value);
cartProvider.update(cart);
showTotalPrice();
}
@Override
public void onButtonSubClick(View view, int value) {
cart.setCount(value);
cartProvider.update(cart);
showTotalPrice();
}
});

}

//设置点击某个item的监听
public interface OnItemClickListener{
void onItemClick(View view,int position);
}

private OnItemClickListener onItemClickListener;
/**
* 设置某条的监听
* @param onItemClickListener
*/
public void setOnItemClickListener(OnItemClickListener onItemClickListener) {
this.onItemClickListener = onItemClickListener;
}

class ViewHolder extends RecyclerView.ViewHolder {
private CheckBox checkbox;
.................
public ViewHolder(View itemView) {
super(itemView);
checkbox = (CheckBox) itemView.findViewById(R.id.checkbox);
iv_icon = (ImageView) itemView.findViewById(R.id.iv_icon);
......
itemView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if(onItemClickListener != null){
onItemClickListener.onItemClick(v,getLayoutPosition());
}
}
});
}
}

public GovaffairPagerAdapter(final Context context, final List<ShopingCart> datas) {
this.context = context;
this.datas = datas;
cartProvider = new CartProvider(context);
showTotalPrice();
setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(View view, int position) {

//1.设置点击item的状态
ShoppingCart ShoppingCart = datas.get(position);
shopingCart.setIsChecked(!shopingCart.isChecked());
notifyItemChanged(position);
//2.设置全选和非全选
checkListener();
//3.显示总价格
showTotalPrice();
// Toast.makeText(context,"选中了"+position,Toast.LENGTH_SHORT).show();
}
});
}

/**
* 全选的监听
*/
private void checkListener() {
int num = 0;
if(datas != null && datas.size()>0){
for(int i=0;i<datas.size();i++){
ShoppingCart cart = datas.get(i);
//只要有一个没有被选中就把全选设置为未勾选
if(!cart.isChecked()){
checkbox_all.setChecked(false);
}else{
num += 1;
}
}
if(datas.size()==num){
checkbox_all.setChecked(true);
}
}
}

   //把CheckBox  和 TextView 传入到适配器中
private final CheckBox checkbox_all;
private final TextView tv_total_price;
private CartProvider cartProvider;

public GovaffairPagerAdapter(final Context context, final List<ShopingCart> datas, final CheckBox checkbox_all, TextView tv_total_price) {
this.context = context;
this.datas = datas;
this.checkbox_all = checkbox_all;
this.tv_total_price = tv_total_price;
..........................
checkbox_all.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//全选和反选
checkAll_none(checkbox_all.isChecked());

showTotalPrice();
}
});
}

/**
* 全选和反选
* @param ischeck
*/
private void checkAll_none(boolean ischeck){
if(datas != null && datas.size() >0){
for(int i=0;i<datas.size();i++){
ShoppingCart cart = datas.get(i);
cart.setIsChecked(ischeck);
notifyItemChanged(i);
}
}
}

//在GovaffairPager类中设置

adapter = new GovaffairPagerAdapter(context,datas,checkbox_all,tv_total_price);