Android：使用来自 itemOnSelected Spinner 的行结果（sqlite）填充 TextView

Question

我想使用微调器作为菜单，以便能够选择锻炼的名称，选择后TextView (x4) 将填充与该名称相关的练习。 目前 Spinner 加载了锻炼名称，并且已经将第一个锻炼加载到每个TextView的onCreation 。

There are no errors when the app is launched, but the other rows don't load into the TextViews when the the new workout name is selected.. One can only assume I have made an error in the logic.

问题：如果这是逻辑错误，有人可以识别它并指出方向吗？

开始.java

    protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_begin);

    loadSpinnerData();
    refreshTextView();



}

   public void loadTextView(){
    DataHelper dataHelper = new DataHelper(this);
    ArrayList<String> exercises = dataHelper.getExercises();



          ((TextView) findViewById(R.id.exercise1)).setText(exercises.get(0));

          ((TextView) findViewById(R.id.exercise2)).setText(exercises.get(1));

          ((TextView) findViewById(R.id.exercise3)).setText(exercises.get(2));

          ((TextView) findViewById(R.id.exercise4)).setText(exercises.get(3));


  }
    public void refreshTextView(){
    Spinner databaseR = (Spinner) findViewById(R.id.databaseR);
    databaseR.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {

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

        }

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

数据助手

  public  String Create_ex="CREATE TABLE ExerciserEasy"
        + " (ID INTEGER PRIMARY KEY AUTOINCREMENT, Workout VARCHAR, ExerciseOne VARCHAR,"
        +"ExerciseTwo VARCHAR, ExerciseThree VARCHAR, ExerciseFour VARCHAR );"

   public ArrayList<String> getExercises(){
    ArrayList<String> list = new ArrayList<String>();
    SQLiteDatabase db = this.getReadableDatabase();
    db.beginTransaction();
    try {
        String selectQuery = " Select * from " + Table_ex1;
        Cursor cursor = db.rawQuery(selectQuery, null);
        if(cursor.moveToFirst()){
            do{
                list.add(cursor.getString(2));
                list.add(cursor.getString(3));
                list.add(cursor.getString(4));
                list.add(cursor.getString(5));
                Log.d("HIITtimer", ""+cursor.getCount());

            }while(cursor.moveToNext());
        }
        db.setTransactionSuccessful();
    }catch (Exception e){
        e.printStackTrace();
    }finally {

        db.endTransaction();
        db.close();


    }
    return list;


}

Answer 1

首先，您需要将选定的锻炼名称传递给loadTextView()以便您可以将其传递给getExercises()并根据该名称查询数据库，其他代码看起来不错，

1- 将参数workoutName添加到getExercises() ，并在WHERE子句中使用它

public ArrayList<String> getExercises(String workoutName){
    //codes ...
    String selectQuery = " Select * from " + Table_ex1 + " WHERE Workout ='" workoutName + "'";
    //codes ...
}

注意：您可能想使用SQLiteDatabase#query()而不是行查询？

2- 将参数workoutName添加到loadTextView() ，并将其传递给getExercises() ：

public void loadTextView(String workoutName){
    //code ...
    ArrayList<String> exercises = dataHelper.getExercises(workoutName);
    //code ...
}

3-通过 Spinner 的setOnItemSelectedListener()选择的锻炼：

@Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
    loadTextView(databaseR.getSelectedItem().toString());
}

现在当 item 被选中时， loadTextView()被调用，告诉方法选择了哪个锻炼，并查询数据库以获取与该锻炼名称相关的记录。