我已經閱讀了很多關於同一個問題的答案,但我仍然不明白爲什麼我的代碼無法正常工作。我有一個問題(我認爲)在兩個活動之間交換數據。 我有2個活動 - 第一個包含ListView和一個添加按鈕。既沒有onActivityResult()也沒有notifyDataSetChanged()工作
當用戶按下添加新的活動開始填寫表格。當用戶完成表格時,他/她按OK鍵,我的第一個活動再次開始(它確實是這樣),它應該包含新項目(但它不包含)。
這是我的第一個活動:
public class DatabaseActivity extends Activity implements OnClickListener {
ArrayList<Student> students;
StudentDatabaseAdapter adapter;
ListView lvStudentList;
ImageButton imgBtnAdd;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.database);
students = new ArrayList<Student>();
fillArrayList();
adapter = new StudentDatabaseAdapter(this, students);
lvStudentList = (ListView)findViewById(R.id.lvStudentsList);
lvStudentList.setAdapter(adapter);
imgBtnAdd = (ImageButton)findViewById(R.id.imagBtnAddStudent);
imgBtnAdd.setOnClickListener(this);
}
public void fillArrayList() {
//code here
}
@Override
public void onClick(View v) {
Intent intent;
intent = new Intent(this, WizardActivity.class);
startActivity(intent);
}
public void addStudent(Student student) {
students.add(student);
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent intent) {
super.onActivityResult(requestCode, resultCode, intent);
if(resultCode==RESULT_OK)
{
if(requestCode==2)
{
if (intent == null) {return;}
Student newStudent = new Student(intent.getStringExtra("name"), intent.getStringExtra("surname"),
intent.getStringExtra("last_name"), Integer.parseInt(intent.getStringExtra("year_of_birth")), R.drawable.default_ava);
addStudent(newStudent);
adapter.notifyDataSetChanged();
}
}
}
}
這就是我的第二個活動:
public class WizardActivity extends Activity implements OnClickListener {
EditText etName, etSurname, etLastName, etYearOfBirth;
ImageButton imgBtnOK;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.wizard);
etName = (EditText)findViewById(R.id.etName);
//initializing other edit texts
imgBtnOK = (ImageButton)findViewById(R.id.imgBtnOK);
imgBtnOK.setOnClickListener(this);
}
@Override
public void onClick(View v) {
Intent intent = new Intent(this, DatabaseActivity.class);
intent.putExtra("name", etName.getText().toString());
intent.putExtra("surname", etSurname.getText().toString());
intent.putExtra("last_name", etLastName.getText().toString());
intent.putExtra("year_of_birth", etYearOfBirth.getText().toString());
setResult(RESULT_OK, intent);
startActivityForResult(intent, 2);
}
}
非常感謝!它幫助! – Lanitka