Android 在 Spinner 中选择项目时如何从 ROOM 数据库获取特定数据

Question

我有一个学生实体，它包含学生姓名、学生手机号码。我正在使用学生姓名添加学生记录，我在添加新记录时从微调器中 selecting 学生姓名。所以我的问题是，当我 select 学生姓名时，我想在微调器下方的文本视图中获取该特定学生的手机号码。

这就是我在微调器中获取所有名称的方式

 private void loadSpinnerData() {
        studentViewModel = ViewModelProviders.of(this).get(StudentViewModel.class);
        studentViewModel.getAllStudents().observe(this, new Observer<List<Student>>() {
            @Override
            public void onChanged(List<Student> students) {
                String[] nameLists = new String[students.size()];
                for (i = 0; i < students.size(); i++) {
                    nameLists[i] = students.get(i).getStudentName() + " " + students.get(i).getStudentFatherName() +
                            " " + students.get(i).getStudentSurname();
                }
                ArrayAdapter<String> studentNames = new ArrayAdapter<>(getApplicationContext(), android.R.layout.simple_spinner_dropdown_item, nameLists);
                studentNames.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
                selectStudentName.setAdapter(studentNames);
            }
        });

    }

这是我的旋转适配器

selectStudentName.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(final AdapterView<?> adapterView, View view, final int position, long l) {
                if ( position == -1 ) {
                    Toast.makeText(AddRecord.this, "No record is selected", Toast.LENGTH_SHORT).show();
                } else {
                    String name = adapterView.getItemAtPosition(position).toString();
                    Toast.makeText(AddRecord.this, name + " is selected", Toast.LENGTH_SHORT).show();
                   for (int i = 0; i < adapterView.getCount(); i++ ){

                   }
                }
            }

如何获得 selected 学生姓名的手机号码？谢谢！

Answer 1

简单亲爱的，只需使用您的视图模型 class object(studentViewModel) 来获取像这样的实时数据实例-

selectStudentName.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(final AdapterView<?> adapterView, View view, final int position, long l) {
                if ( position == -1 ) {
                    Toast.makeText(AddRecord.this, "No record is selected", Toast.LENGTH_SHORT).show();
                } else {
                    String studentMobileNumber = studentViewModel.getAllStudents().getValue().get(position).getMobileNumber()

                }
            }

Android 在 Spinner 中选择项目时如何从 ROOM 数据库获取特定数据

How to get specific data from ROOM database when an item is selected in Spinner in Android

android

android-spinner