Question

我有800个标题用于实现列表视图。我将这800个标题放在一个字符串数组中，然后尝试填充列表视图，但是当我尝试运行时，我只能显示至少10个元素。当我尝试使用搜索栏搜索标题时，可以找到它，然后在删除过滤器搜索时可以看到标题的总数组。我错了吗？这是代码：

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_titoli);

        btt_backHome = (Button) findViewById(R.id.btt_backHome);
        lV_titoli = (ListView) findViewById(R.id.lV_titoli);
        eT_search = (EditText) findViewById(R.id.eT_search);

        adapter = ArrayAdapter.createFromResource(this, R.array.titoli, android.R.layout.simple_list_item_1);
        adapter_testi = ArrayAdapter.createFromResource(this, R.array.testi, android.R.layout.simple_list_item_1);
        lV_titoli.setAdapter(adapter);

        final Intent refresh = new Intent(this, activity_titoli.class);
        final Intent to_Home = new Intent (this , Activity_Main.class);
        final Intent to_Canzone_from_titoli = new Intent (this , activity_canzone.class);

        eT_search.addTextChangedListener(new TextWatcher() {

            @Override
            public void afterTextChanged(Editable arg0) {
                // TODO Auto-generated method stub

            }

            @Override
            public void beforeTextChanged(CharSequence arg0, int arg1,
                                          int arg2, int arg3) {
                // TODO Auto-generated method stub
            }

            @Override
            public void onTextChanged(CharSequence arg0, int arg1, int arg2,
                                      int arg3) {
                (activity_titoli.this).adapter.getFilter().filter(arg0);
            }
        });

我已经验证了名为“ titoli”的字符串数组是正确的。

Answer 1

这是一种特殊的行为，但由于过滤器可以解决，请尝试：

class Registration < ApplicationRecord

  belongs_to :student
  belongs_to :course

  validates_uniqueness_of :student_id, :scope => :course_id
  validate :period_is_free


  private

  def period_is_free
    if student.courses.where(period: course.period)
      errors.add(:courses, "Student is already registered for a class at this period")
    end
  end
end

紧接着

adapter.getFilter().filter("");

列表视图仅显示少量元素

1 个答案: