如何在 Android Studio 中使用微调器实现 SQLite 加入，以便从表中获取 id

Question

我在SQLite数据库中创建了2个表，并且stoksalesat DatabaseHelper.java创建表stokString tbStok = "CREATE TABLE stok(id_stok INTEGER PRIMARY KEY AUTOINCREMENT, waktu_stok DATETIME, id_sales INTEGER, stok INTEGER, FOREIGN KEY id_sales REFERENCES sales(id_sales)";创建表salesString tbSales = "CREATE TABLE sales(id_sales INTEGER PRIMARY KEY AUTOINCREMENT, nama VARCHAR, kodesales VARCHAR, username VARCHAR, password VARCHAR, level INTEGER)";从 SQLite 创建列表数据public List<String> getSpinnerSales(){    List<String> labels = new ArrayList<String>();    // Select All Query    String selectQuery = "SELECT  * FROM " + "sales";    SQLiteDatabase db = this.getReadableDatabase();    Cursor cursor = db.rawQuery(selectQuery, null);    // looping through all rows and adding to list    if (cursor.moveToFirst()) {        do {            labels.add(cursor.getString(0));            labels.add(cursor.getString(1));        } while (cursor.moveToNext());    }    // closing connection    cursor.close();    db.close();    // returning lables    return labels;}在微调器上显示private void loadSpinnerSales() {    // database handler    DatabaseHelper db = new DatabaseHelper(getApplicationContext());    // Spinner Drop down elements    List<String> lables = db.getSpinnerSales();    // Creating adapter for spinner    ArrayAdapter<String> dataAdapter = new ArrayAdapter<String>(this,            android.R.layout.simple_spinner_item, lables);    // Drop down layout style - list view with radio button    dataAdapter            .setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);    // attaching data adapter to spinner    spsales.setAdapter(dataAdapter);}我需要将值保存到其他表 SQLite，但微调器必须显示销售名称。id_sales

Answer 1

最好的方法是使用自定义适配器，然后您可以将对象列表（在您的情况下是“销售ID和名称列表”）传递给适配器而不仅仅是字符串列表，然后在选择的项目上，您将获得所选对象，然后您可以获得所需的任何id或名称，您可以按照此链接使自定义适配器 https://abhiandroid.com/ui/custom-spinner-examples.html

Answer 2

我通过编辑代码来解决这个问题

// looping through all rows and adding to list

        if (cursor.moveToFirst()) {

            do {

                labels.add(cursor.getString(0)+cursor.getString(1));

            } while (cursor.moveToNext());

        }

并在项目上的微调器上选择使用子字符串进行操作

spsupir.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {

            @Override

            public void onItemSelected(AdapterView<?> parent, View view, int position,long id) {

                String label = parent.getItemAtPosition(position).toString();

                String ids = String.valueOf(label).substring(0,1);

                Log.d("label:", ids);

            }

            @Override

            public void onNothingSelected(AdapterView<?> adapterView) {

            }

        });

已编辑的代码

String label = parent.getItemAtPosition(position).toString();

String ids = String.valueOf(label).substring(0,1);

Log.d("label:", ids);

Answer 3

另一个解决问题

步骤 1 创建模型类

public class Sales {

    String id_sales,nama;

    public Sales(String id_sales, String nama) {

        this.id_sales = id_sales;

        this.nama = nama;

    }

    public String getId_sales() {

        return id_sales;

    }

    public void setId_sales(String id_sales) {

        this.id_sales = id_sales;

    }

    public String getNama() {

        return nama;

    }

    public void setNama(String nama) {

        this.nama = nama;

    }

    @Override

    public String toString() {

        return nama;

    }

}

步骤 2 从 SQLite 表销售中放入所有数据

//Data spinner supir

    public ArrayList<Sales> getSpinnerSales(){

        ArrayList<Sales> salesList = new ArrayList<>();

        // Select All Query

        String selectQuery = "SELECT  * FROM " + "sales";

        SQLiteDatabase db = this.getReadableDatabase();

        Cursor cursor = db.rawQuery(selectQuery, null);

        // looping through all rows and adding to list

        if (cursor.moveToFirst()) {

            do {

                salesList.add(new Sales(cursor.getString(0), cursor.getString(1)));

            } while (cursor.moveToNext());

        }

        // closing connection

        cursor.close();

        db.close();

        // returning lables

        return salesList;

    }

步骤 3 生成 void 以使用 sqlite aa 活动中的数据

private void loadSpinnerSales() {

        // database handler

        DatabaseHelper db = new DatabaseHelper(getApplicationContext());

        ArrayList<Sales> salesList = db.getSpinnerSales();

        ArrayAdapter<Sales> adapter = new ArrayAdapter<Sales>(this, android.R.layout.simple_spinner_dropdown_item, salesList);

        spsales.setAdapter(adapter);

    }

步骤 4 在 OnCreate 上加载方法

    spsales = (Spinner) findViewById(R.id.spSales);

    loadSpinnerSales();

    spsales.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {

        @Override

        public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {

            Sales sales = (Sales) parent.getSelectedItem();

            Toast.makeText(getApplicationContext(),sales.getId_sales(),Toast.LENGTH_SHORT).show();

        }

        @Override

        public void onNothingSelected(AdapterView<?> parent) {

        }

    });