我創建了一個具有多個片段的活動。當在一個片段中點擊一個按鈕(圖片)時,片段被替換爲一個新的片段。這工作正常。 其中一個圖像/按鈕是打開添加頁面的「添加」按鈕。在這個片段中有幾個EditText和一個按鈕'Insert'。通過onClick從片段獲取EditText值
當按下「插入」按鈕時,必須檢索Edittext值。這是它出錯的地方。
這是我的代碼(我排除了什麼似乎沒有必要): MainActicity.java:
public class MainActivity extends AppCompatActivity {
FragmentTransaction fragmentTransaction;
EditText etDistancesInsertDays;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
etDistancesInsertDays = (EditText)findViewById(R.id.etDistancesInsertDays);
// On create display home page (HomeFragment)
Fragment frRecords = new RecordsFragment();
fragmentTransaction = getSupportFragmentManager().beginTransaction();
fragmentTransaction.add(R.id.main_container, frRecords);
fragmentTransaction.commit();
}
public void openDistancesInsert(){
fragmentTransaction = getSupportFragmentManager().beginTransaction();
fragmentTransaction.replace(R.id.main_container, new DistanceInsertFragment());
fragmentTransaction.commit();
getSupportActionBar().setTitle(getString(R.string.frTitleDistanceInsert));
}
public void switchFragment(View view){
switch (view.getId()) {
case R.id.btnInsertDistance:
// Trial 1
EditText etText = (EditText)findViewById(R.id.etDistancesInsertDays);
String strDays = etDistancesInsertDays.getText().toString();
// Caused by: java.lang.NullPointerException
Toast.makeText(MainActivity.this, "Days: "+strDays, Toast.LENGTH_LONG).show();
// Trial 2
Fragment frInsert;
frInsert = getSupportFragmentManager().findFragmentById(R.id.frDistanceInsert);
View frViewInsert;
frViewInsert = frInsert.getView();
// Caused by: java.lang.NullPointerException
EditText etText = (EditText)frViewInsert.findViewById(R.id.etDistancesInsertDays);
String strDays = etDistancesInsertDays.getText().toString();
Toast.makeText(MainActivity.this, "Days: "+strDays, Toast.LENGTH_LONG).show();
break;
}
}
}
而且我DistanceInsertFragment.java
public class DistanceInsertFragment extends Fragment {
EditText etDistancesInsertDays, etDistancesInsertMonths, etDistancesInsertYears;
public DistanceInsertFragment() {
// Required empty public constructor
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View frViewInsert = inflater.inflate(R.layout.fragment_distance_insert, container, false);
// Set current dat in text field:
Calendar c = Calendar.getInstance();
String strDayOfMonth = Integer.toString(c.get(Calendar.DAY_OF_MONTH));
String strMonthOfYear = Integer.toString(c.get(Calendar.MONTH)+1);
String strYear = Integer.toString(c.get(Calendar.YEAR));
etDistancesInsertDays = (EditText)frViewInsert.findViewById(R.id.etDistancesInsertDays);
etDistancesInsertMonths = (EditText)frViewInsert.findViewById(R.id.etDistancesInsertMonths);
etDistancesInsertYears = (EditText)frViewInsert.findViewById(R.id.etDistancesInsertYears);
etDistancesInsertDays.setText(strDayOfMonth);
etDistancesInsertMonths.setText(strMonthOfYear);
etDistancesInsertYears.setText(strYear);
return frViewInsert;
}
}
兩個審判1和2給錯誤「由java.lang.NullPointerException引發」。雖然我不知道笏意味着它..
其中是您的按鈕在activity_main佈局或fragment_distance_insert佈局?因爲我沒有看到任何onclicklisterner定義。 –
我看到你的Activity中有一個onClick方法,該按鈕是否假設在一個片段內而另一個片段內的EditText? –
onClick確實在Activity內。 Button和EditText在同一個Fragment中。我的錯誤已經被亞倫發現了,我將這些錯誤分配給了他。 – Chris