如何在微調器中檢索所選項目的 int 值？

Question

我正在為 android 制作一個關系數據庫應用程序，它根據我用來填充微調器的選定 id 顯示發票。 微調器正確填充，但我需要為保存 SQL 的viewInvoice方法的參數獲取 id（不是微調器的索引）的整數值。 我曾嘗試使用getSelectedItem方法，但這似乎不能滿足我的需求。

這是微調器的代碼：

package com.example.dh0020348.inventory;

import android.app.AlertDialog;
import android.database.Cursor;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Spinner;
import android.widget.TextView;

public class ViewAllCustomers extends AppCompatActivity {
DbHelper db;
TextView id, name, email, address, city, state, zip, phone, invoiceID;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_view_all_customers);
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);
    db = new DbHelper(this);

    final Spinner spinner = (Spinner) findViewById(R.id.spinnerInvoiceID);

    DbBackend dbBackend = new DbBackend(ViewAllCustomers.this);
    String[] spinnerLists = dbBackend.getAllSpinnerContent();

    ArrayAdapter<String> spinnerAdapter = new ArrayAdapter<String>(ViewAllCustomers.this,android.R.layout.simple_spinner_item, spinnerLists);
    spinnerAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    spinner.setAdapter(spinnerAdapter);
    spinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
        @Override
        public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
            double total;
            Cursor res = db.viewInvoice(Integer.parseInt(String.valueOf(spinner.getSelectedItem())));
            if (res.getCount() == 0) {
                // show message
                showMessage("Error", "Nothing found");
                return;
            }
            StringBuffer buffer = new StringBuffer();

            buffer.append("Invoice ID: " + res.getString(0) + "\n");
            buffer.append("Date: " + res.getString(1) + "\n");
            buffer.append("Name: " + res.getString(2) + "\n");
            buffer.append("Street Address: " + res.getString(8) + "\n");
            buffer.append("City: " + res.getString(9) + "\n");
            buffer.append("State: " + res.getString(10) + "\n");
            buffer.append("Zip Code: " + res.getString(11) + "\n");
            buffer.append("Phone: " + res.getString(12) + "\n");
            buffer.append("Item: " + res.getString(4) + "\n");
            buffer.append("Size: " + res.getString(5) + "\n");
            buffer.append(String.format("Price Per Item: %.2f", Double.parseDouble(res.getString(7))) + "\n");
            buffer.append("Quantity: " + res.getString(6) + "\n");
            total = Double.parseDouble(res.getString(7)) * Double.parseDouble(res.getString(6));
            buffer.append(String.format("Total Price: %.2f", total));

            // show all data
            showMessage("Data", buffer.toString());
        }

        @Override
        public void onNothingSelected(AdapterView<?> parent) {

        }
    });

    id = (TextView) findViewById(R.id.lblCustomerID);
    name = (TextView) findViewById(R.id.lblCustomerName);
    email = (TextView) findViewById(R.id.lblCustomerEmail);
    address = (TextView) findViewById(R.id.lblCustomerAddress);
    city = (TextView) findViewById(R.id.lblCity);
    state = (TextView) findViewById(R.id.lblState);
    zip = (TextView) findViewById(R.id.lblZip);
    phone = (TextView) findViewById(R.id.lblPhone);
    invoiceID = (TextView) findViewById(R.id.lblInvoice);

    ViewAllCustomers();
//        ViewCustomerInvoices();
    getSupportActionBar().setDisplayHomeAsUpEnabled(true);

}

//display the StringBuffer message
public void showMessage(String title, String Message){
    AlertDialog.Builder builder = new AlertDialog.Builder(this);
    builder.setCancelable(true);
    builder.setTitle(title);
    builder.setMessage(Message);
    builder.show();
}

public void ViewAllCustomers(){

    Cursor res = db.viewAllCustomers();
    while (res.moveToNext()) {
        id.setText("ID: " + res.getString(0));
        name.setText("Name: " + res.getString(1));
        email.setText("Email: " + res.getString(2));
        address.setText("Address: " + res.getString(3));
        city.setText("City: " + res.getString(4));
        state.setText("State: " + res.getString(5));
        zip.setText("Zip: " + res.getString(6));
        phone.setText("Phone: " + res.getString(7));
        invoiceID.setText("Invoice ID:");
    }
}
}

這是我的DbHelper類中的查詢方法：

 //view a single saved invoice
public Cursor viewInvoice(int id){
    SQLiteDatabase db = this.getWritableDatabase();
    Cursor res = db.rawQuery("SELECT ord." + INVOICE_ID + ", " + INVOICE_DATE + ", " + C_CUSTOMER_NAME + ", cus."
            + C_CUSTOMER_ID + ", inventory." + INVENTORY_ITEM + ", " + ORDERED_SIZE + ", " + ORDERED_QUANTITY + ", "
            + INVENTORY_PRICE + ", " + C_STREET_ADDRESS + ", " + C_CITY + ", " + C_STATE +
            ", " + C_ZIP + ", " + C_PHONE +
            " FROM " + TABLE_INVOICE + " as inv INNER JOIN " + TABLE_CUSTOMER + " as cus " +
            "ON inv." + C_CUSTOMER_ID + " = " + "cus." + C_CUSTOMER_ID +
            " INNER JOIN " + TABLE_ORDERED + " as ord ON inv." + INVOICE_ID + " = " + "ord." + ORDERED_ID +
            " INNER JOIN " + TABLE_INVENTORY + " as inventory " +
            "ON ord." + INVENTORY_ID + " = " + " inventory." + INVENTORY_ID, null);
    if(res != null)
        res.moveToFirst();
    return res;
}

Answer 1

你試過 spinner.getSelectedItem().toString();

然后將其投射到您填充它的任何對象。

Answer 2

使用spinnerAdapter.getSelectedItemId() ，如果未選擇任何內容，它將返回當前選擇的項目 ID 或INVALID_ROW_ID (-9223372036854775808)。

Answer 3

你可以通過兩種方式做到這一點，

1] 使用微調項位置，

int myNum = 0;

    try {
        myNum = Integer.parseInt(Spinner_NAME.get(position).toString());
    } catch(NumberFormatException nfe) {
       Log.e("","Exception :: "+nfe);
    }

2] 如果您使用任何模型類或任何數組列表，那么，

int myNum = Integer.parseInt(spinner1.getModel().getValue().toString());