【发布时间】：2019-03-02 12:10:58
【问题描述】：
我是编程新手，如果您能帮助我，那就太好了。我有一个 Activity，它有一个按钮和一个列表视图。列表视图上的值是名称、价格、类别和数量，并通过适配器定义。我想知道如何将每行的数量值乘以价格值并将所有这些值相加，并在单击按钮时将结果显示在吐司中。 Here's 它的图形以便更好地理解它。
代码如下：
CartListActivity.java
public class CartListActivity extends AppCompatActivity {
ListView userList;
UserCustomAdapter userAdapter;
ArrayList<User> userArray = new ArrayList<User>();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_cart_list);
Button payBtn = (Button)findViewById(R.id.payBtn);
payBtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Toast.makeText(getApplicationContext(), "Total: x€", Toast.LENGTH_SHORT).show();
}
});
/**
* add item in arraylist
*/
userArray.add(new User("Olives verdes", "1,20€", "Aperitius", "0"));
userArray.add(new User("Olives negres", "1,30€", "Aperitius", "0"));
userArray.add(new User("Cogombrets", "1,80€", "Aperitius","0"));
userArray.add(new User("Patates Lay's", "1,19€", "Aperitius","0"));
userArray.add(new User("Potet", "0,95€", "Bebè","0"));
userArray.add(new User("Biberó", "3,85€", "Bebè","0"));
userArray.add(new User("Tovalloletes", "1,10€", "Bebè","0"));
userArray.add(new User("Perxes de nadó", "1,95€", "Bebè","0"));
/**
* set item into adapter
*/
userAdapter = new UserCustomAdapter(CartListActivity.this, R.layout.view_row,
userArray);
userList = (ListView) findViewById(R.id.listView);
userList.setItemsCanFocus(false);
userList.setAdapter(userAdapter);
/**
* get on item click listener
*/
userList.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View v,
final int position, long id) {
Log.i("List View Clicked", "**********");
Toast.makeText(CartListActivity.this,
"List View Clicked:" + position, Toast.LENGTH_LONG)
.show();
}
});
}
}UserCustomAdapter.java
public class UserCustomAdapter extends ArrayAdapter<User> {
Context context;
int layoutResourceId;
ArrayList<User> data = new ArrayList<User>();
public UserCustomAdapter(Context context, int layoutResourceId,
ArrayList<User> data) {
super(context, layoutResourceId, data);
this.layoutResourceId = layoutResourceId;
this.context = context;
this.data = data;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
View row = convertView;
UserHolder holder = null;
if (row == null) {
LayoutInflater inflater = ((Activity) context).getLayoutInflater();
row = inflater.inflate(layoutResourceId, parent, false);
holder = new UserHolder();
holder.textName = (TextView) row.findViewById(R.id.textView1);
holder.textPrice = (TextView) row.findViewById(R.id.textView2);
holder.textCategory = (TextView) row.findViewById(R.id.textView3);
holder.textQuantity = (TextView) row.findViewById(R.id.quantityTxt);
holder.btnEdit = (Button) row.findViewById(R.id.button1);
holder.btnDelete = (Button) row.findViewById(R.id.button2);
row.setTag(holder);
} else {
holder = (UserHolder) row.getTag();
}
final User user = data.get(position);
holder.textName.setText(user.getName());
holder.textPrice.setText(user.getPrice());
holder.textCategory.setText(user.getCategory());
holder.textQuantity.setText(user.getQuantity());
final UserHolder finalHolder = holder;
holder.btnEdit.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
String value1 = finalHolder.textQuantity.getText().toString();
int a = Integer.parseInt(value1);
if(a <= 99) {
int sum = a + 1;
Log.i("Edit Button Clicked", "**********");
user.setQuantity(Integer.toString(sum));
finalHolder.textQuantity.setText(Integer.toString(sum));
}
}
});
holder.btnDelete.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
String value2 = finalHolder.textQuantity.getText().toString();
int a = Integer.parseInt(value2);
if(a > 0) {
int substract = a - 1;
Log.i("Delete Button Clicked", "**********");
user.setQuantity(Integer.toString(substract));
finalHolder.textQuantity.setText(Integer.toString(substract));
}
}
});
return row;
}
static class UserHolder {
TextView textName;
TextView textPrice;
TextView textCategory;
TextView textQuantity;
Button btnEdit;
Button btnDelete;
}
}用户.java
public class User {
String name;
String price;
String category;
String quantity;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPrice() {
return price;
}
public void setPrice(String price) {
this.price = price;
}
public String getCategory() {
return category;
}
public void setCategory(String category) {
this.category = category;
}
public String getQuantity() {
return quantity;
}
public void setQuantity(String quantity) {
this.quantity = quantity;
}
public User(String name, String price, String category, String quantity) {
super();
this.name = name;
this.price = price;
this.category = category;
this.quantity = quantity;
}
}【问题讨论】：
标签： java android arrays listview