我正在使用ProductsList的ArrayList从自定义适配器生成ListView以进行购物车活动。一切正常，除了我必须在项目显示之前返回活动三次。我正在调用一个xml，ListView列在RelativeLayout下面。为凌乱的代码道歉，我还在学习android。非常感谢任何帮助！
Cart.java：
/accountProductAdapter.java：
public class Cart extends AppCompatActivity {
private String user;
static final String TAG = "";
static ArrayList<Product> cartItems = new ArrayList<>();
ProductAdapter adaptCart;
ListView listView;
static int cartSize = 0;
Menu menu;
float shipCost = 15;
float tax = (float)0.07;
float taxRate = (float) 0.07;
TextView subTotal;
TextView shipping;
TextView taxes;
TextView cTaxes;
TextView totals;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_cart);
user = MainActivity.currentAccount.getUsername();
if(user == null || user.equals("Guest")) {
shipCost = (float)0.00;
tax = (float)0.00;
}
if(user != null && !(user.equals("Guest"))) {
new getCartIcon().execute();
//cartItems = new ArrayList<>();
if(getCartNumber() != cartItems.size()) {
cartSize = ProductAdapter.getCartSize();
new refreshCartIcon().execute();
}
if(cartItems == null || cartItems.size() != getCartNumber()) {
new returnCartItems().execute();
}
Log.d(TAG, "cartItems size: " + String.valueOf(cartItems.size()));
Log.d(TAG, "cartNumb size: " + getCartNumber());
if(getCartNumber() == cartItems.size()) {
listView = (ListView) findViewById(R.id.list_cart_view);
adaptCart = new ProductAdapter(Cart.this, 0, cartItems);
adaptCart.notifyDataSetChanged();
}
if(listView != null) {
adaptCart.notifyDataSetChanged();
listView.setAdapter(adaptCart);
}
//listView.notifyAll();
}
//}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
super.onCreateOptionsMenu(menu);
getMenuInflater().inflate(R.menu.menu_main, menu);
this.menu = menu;
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_login){
setContentView(R.layout.activity_login);
Button logB = (Button) findViewById(R.id.logB);
logB.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
EditText user_Name, user_Pass;
String password, username;
user_Name = (EditText) findViewById(R.id.editText_username);
user_Pass = (EditText) findViewById(R.id.editText_password);
password = user_Pass.getText().toString();
username = user_Name.getText().toString();
MainActivity.currentAccount.setPassword(password);
MainActivity.currentAccount.setUsername(username);
new userLog().execute();
}
});
}
if (id == R.id.action_register) {
setContentView(R.layout.activity_register);
Button logB = (Button) findViewById(R.id.logR);
logB.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
EditText user_First, user_Last, user_Email, user_Name, user_Pass;
String first, last, email, password, username;
user_First = (EditText) findViewById(R.id.editText_firstName);
user_Last = (EditText) findViewById(R.id.editText_lastName);
user_Email = (EditText) findViewById(R.id.editText_email);
user_Name = (EditText) findViewById(R.id.editText_username);
user_Pass = (EditText) findViewById(R.id.editText_password);
first = user_First.getText().toString();
last = user_Last.getText().toString();
email = user_Email.getText().toString();
password = user_Pass.getText().toString();
username = user_Name.getText().toString();
MainActivity.currentAccount.setFirst_name(first);
MainActivity.currentAccount.setLast_name(last);
MainActivity.currentAccount.setEmail(email);
MainActivity.currentAccount.setPassword(password);
MainActivity.currentAccount.setUsername(username);
new userReg().execute();
}
});
}
if (id == R.id.action_cart) {
new getCartIcon().execute();
startActivity(new Intent(getApplicationContext(), Cart.class));
}
if (id == R.id.action_search) {
new getCartIcon().execute();
startActivity(new Intent(getApplicationContext(), Search.class));
}
if (id == R.id.action_account) {
new getCartIcon().execute();
startActivity(new Intent(getApplicationContext(), AccountActivity.class));
}
if (id == R.id.action_about_us) {
setContentView(R.layout.activity_about_us);
}
if (MainActivity.currentAccount != null && id == R.id.action_logout) {
MainActivity.currentAccount.setFirst_name("Guest");
MainActivity.currentAccount.setLast_name("");
MainActivity.currentAccount.setEmail("");
MainActivity.currentAccount.setPassword("");
MainActivity.currentAccount.setUsername("Guest");
setContentView(R.layout.activity_main);
setUser(MainActivity.currentAccount);
new getCartIcon().execute();
}
return super.onOptionsItemSelected(item);
}
public class getCartIcon extends AsyncTask<Void, Void, Void> {
String tempUser = user;
int cartNum = 0;
float tempTotal;
@Override
protected void onPreExecute() {
subTotal = (TextView) findViewById(R.id.textView_subTotal);
shipping = (TextView) findViewById(R.id.textView_shipping);
totals = (TextView) findViewById(R.id.textView_total);
taxes = (TextView) findViewById(R.id.textView_taxes);
cTaxes = (TextView) findViewById(R.id.current_taxes);
}
@Override
protected Void doInBackground(Void... arg0) {
if(tempUser != null) {
try {
Connection conn = ConnectDB.getConnection();
String queryString = "SELECT * FROM Orders WHERE `User_Name` = '" + tempUser + "'";
PreparedStatement st = conn.prepareStatement(queryString);
//st.setString(1, tempUser);
final ResultSet result = st.executeQuery(queryString);
while (result.next()) {
try {
tempTotal += result.getFloat("Price");
//skus.add(result.getInt("SKU"));
} catch(SQLException e) {
e.printStackTrace();
}
cartNum++;
//setTotal(result.getFloat(String.valueOf("Price")));
}
} catch (Exception e) {
e.printStackTrace();
}
}
return null;
}
protected void onPostExecute(Void result) {
String taxation = "Taxes @ %" + String.valueOf(taxRate);
getCartItems(cartNum);
subTotal.setText(String.format("%.2f", Float.parseFloat(String.valueOf(tempTotal))));
if(tempTotal == 0) {
shipCost = 0;
}
shipping.setText(String.format("%.2f", Float.parseFloat(String.valueOf(shipCost))));
tax = tempTotal * tax;
cTaxes.setText(taxation);
taxes.setText(String.format("%.2f", Float.parseFloat(String.valueOf(tax))));
totals.setText(String.format("%.2f", Float.parseFloat(String.valueOf(tempTotal + shipCost + tax))));
//new returnCartItems().execute();
//setTotal(tempTotal);
setCartNumber(cartNum);
super.onPostExecute(result);
}
}
public class refreshCartIcon extends AsyncTask<Void, Void, Void> {
String tempUser = user;
int cartNum = 0;
@Override
protected void onPreExecute() {
}
@Override
protected Void doInBackground(Void... arg0) {
if(tempUser != null) {
try {
Connection conn = ConnectDB.getConnection();
String queryString = "SELECT * FROM Orders WHERE `User_Name` = '" + tempUser + "'";
PreparedStatement st = conn.prepareStatement(queryString);
//st.setString(1, tempUser);
final ResultSet result = st.executeQuery(queryString);
while (result.next()) {
cartNum++;
}
} catch (Exception e) {
e.printStackTrace();
}
}
return null;
}
protected void onPostExecute(Void result) {
getCartItems(cartNum);
setCartNumber(cartNum);
super.onPostExecute(result);
}
}
public class returnCartItems extends AsyncTask<Void, Void, Void> {
String tempUser = user;
Product product = null;
ArrayList<Product> tempItems = new ArrayList<>();
List<Integer> skus = new ArrayList<>();
@Override
protected void onPreExecute() {
}
@Override
protected Void doInBackground(Void... arg0) {
if(tempUser != null) {
if ((getCartNumber() > 0 && cartItems == null) ||
(cartItems.size() != getCartNumber())) {
try {
Connection conn = ConnectDB.getConnection();
String queryString = "SELECT * FROM Orders WHERE `User_Name` = '" + tempUser + "'";
PreparedStatement st = conn.prepareStatement(queryString);
final ResultSet result = st.executeQuery(queryString);
while (result.next()) {
try {
skus.add(result.getInt("SKU"));
} catch (SQLException e) {
e.printStackTrace();
}
}
conn.close();
} catch (Exception e) {
e.printStackTrace();
}
try {
Connection conn = ConnectDB.getConnection();
String queryString = "SELECT * FROM Inventory";
PreparedStatement st = conn.prepareStatement(queryString);
final ResultSet result = st.executeQuery(queryString);
while (result.next()) {
for (int i = 0; i < skus.size(); i++) {
if (skus.get(i) == result.getInt("SKU")) {
product = new Product();
product.setProduct_name(result.getString("Name"));
product.setSKU(result.getInt("SKU"));
product.setProduct_dept(result.getString("Department"));
product.setProduct_desc(result.getString("Description"));
product.setPrice(result.getFloat("Price"));
product.setProduct_qty(result.getInt("Quantity")-(result.getInt("Quantity")-1));
product.setProduct_img(result.getString("Image"));
tempItems.add(product);
}
}
}
conn.close();
} catch (Exception e) {
e.printStackTrace();
}
}
}
return null;
}
protected void onPostExecute(Void result) {
setCartItems(tempItems);
super.onPostExecute(result);
}
}
public void setCartItems(ArrayList<Product> cartItems) {
this.cartItems = cartItems;
}
public class userLog extends AsyncTask<Void, Void, Void> {
String queryResult = "";
@Override
protected Void doInBackground(Void... arg0) {
try {
Connection conn = ConnectDB.getConnection();
if(conn != null) {
queryResult = "Successfully connected!";
Login.login(MainActivity.currentAccount, conn);
}
else {
queryResult = "Error in connection";
}
}
catch(Exception e) {
e.printStackTrace();
}
return null;
}
protected void onPostExecute(Void result) {
setUser(MainActivity.currentAccount);
//getData.setText(queryResult);
new getCartIcon().execute();
super.onPostExecute(result);
}
}
public class userReg extends AsyncTask<Void, Void, Void> {
String queryResult = "";
@Override
protected Void doInBackground(Void... arg0) {
try {
Connection conn = ConnectDB.getConnection();
if(conn != null) {
queryResult = "Successfully connected!";
Register.register(MainActivity.currentAccount, conn);
conn.close();
}
else {
queryResult = "Error in connection";
}
}
catch(Exception e) {
e.printStackTrace();
}
return null;
}
protected void onPostExecute(Void result) {
setUser(MainActivity.currentAccount);
//getData.setText(queryResult);
super.onPostExecute(result);
}
}
public void getCartItems(int cart) {
MenuItem cartMenuItem = (MenuItem) menu.findItem(R.id.action_cart);
if (cart == 0) {
cartMenuItem.setIcon(R.drawable.cart0);
}
if (cart == 1) {
cartMenuItem.setIcon(R.drawable.cart1);
}
if (cart == 2) {
cartMenuItem.setIcon(R.drawable.cart2);
}
if (cart == 3) {
cartMenuItem.setIcon(R.drawable.cart3);
}
if (cart == 4) {
cartMenuItem.setIcon(R.drawable.cart4);
}
if (cart == 5) {
cartMenuItem.setIcon(R.drawable.cart5);
}
if (cart > 5) {
cartMenuItem.setIcon(R.drawable.cart5plus);
}
if (cart > 10) {
cartMenuItem.setIcon(R.drawable.cart10plus);
}
}
public void setUser(Account acct) {
String aloha;
if(acct.getFirst_name() != null) {
aloha = "Welcome, " + acct.getFirst_name() + "!";
}
else {
aloha = "Welcome, Guest!";
}
setContentView(R.layout.activity_main);
TextView textName = (TextView) findViewById(R.id.textView_hello);
textName.setTextSize(22);
textName.setText(aloha);
}
public void setCartNumber(int cartSize) {
this.cartSize = cartSize;
}
public static Integer getCartNumber() {
return cartSize;
}
public static ArrayList<Product> getCartList() {
return cartItems;
}
}