我有个问题。当我单击“添加练习”并打开添加对话框以放置一些信息时，即使我旋转设备，一切正常。但是当我使用“编辑对话框”旋转设备时，应用程序崩溃了，请帮帮我。需要一些东西来防止它。（我不是程序员，所以对我来说并不容易）
public class ShowExercisesListActivity extends ListActivity {
private static final String TAG = "Exercises";
private List<Exercise> mExercises;
private LayoutInflater mInflater;
private ArrayAdapter<Exercise> mArrayAdapter;
private View mAddExerciseDialogLayout;
private Context mContext;
private EditText exerciseName;
private static final int DIALOG_ADD_EXERCISE = 0;
// package scope, since it is accessed in inner classes
WorkoutTrackerApp mApp;
/**
* Called when the activity is first created.
*
*/
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.type_list);
mApp = (WorkoutTrackerApp) getApplication();
mInflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
mExercises = DBUtil.fetchAllExercises(this);
mArrayAdapter = new ArrayAdapter<Exercise>(this, R.layout.type_list_item, mExercises) {
@Override
public View getView(int position, View convertView, ViewGroup parent) {
View row;
if (null == convertView) {
row = mInflater.inflate(R.layout.type_list_item, null);
} else {
row = convertView;
}
Exercise type = (Exercise) mExercises.get(position);
TextView tv = (TextView) row.findViewById(android.R.id.text1);
tv.setText(type.getName());
return row;
}
};
setListAdapter(mArrayAdapter);
//dialog box layout
mContext = this;
LayoutInflater inflater = (LayoutInflater) mContext.getSystemService(LAYOUT_INFLATER_SERVICE);
mAddExerciseDialogLayout = inflater.inflate(R.layout.add_type_dialog, (ViewGroup) findViewById(R.id.type_layout_root));
exerciseName = (EditText) mAddExerciseDialogLayout.findViewById(R.id.type_name);
//register for context menu
registerForContextMenu(getListView());
if (mExercises.size() == 0) {
// if there are no exercises initially, then show the add type dialog
showDialog(DIALOG_ADD_EXERCISE);
}
//Начало:Активация кнопки "Добавить упражнение"
Button addExerciseButton = (Button) findViewById(R.id.menu_add_exercise);
addExerciseButton.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
mApp.setCurrrentDialogStatus(DialogStatus.ADD);
showDialog(DIALOG_ADD_EXERCISE);
}
});
//Конец: Активация кнопки "Добавить упражнение"
//Начало:Активация иконки Верхней плашки
ImageButton GoHomeButton = (ImageButton) findViewById(R.id.imageButton1);
GoHomeButton.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
Intent myIntent5 = new Intent(ShowExercisesListActivity.this, AndroidApp.class);
ShowExercisesListActivity.this.startActivity(myIntent5);
}
});
//Конец:Активация иконки Верхней плашки
}
@Override
protected void onListItemClick(ListView l, View v, int position, long id) {
Exercise type = mExercises.get(position);
Log.v(TAG, "Clicked " + type.getName() + "Id: " + type.getId());
Intent intent = new Intent(this.getApplicationContext(),
TabWidget.class);
intent.putExtra("typeId", type.getId());
startActivity(intent);
}
/**
* When the context menu is created
*
* @see android.app.Activity#onCreateContextMenu(android.view.ContextMenu, android.view.View, android.view.ContextMenu.ContextMenuInfo)
*/
@Override
public void onCreateContextMenu(ContextMenu menu, View v, ContextMenuInfo menuInfo) {
super.onCreateContextMenu(menu, v, menuInfo);
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.exercise_context_menu, menu);
}
/**
* When a context menu item is selected
*
* @see android.app.Activity#onContextItemSelected(android.view.MenuItem)
*/
@Override
public boolean onContextItemSelected(MenuItem item) {
AdapterContextMenuInfo info = (AdapterContextMenuInfo) item.getMenuInfo();
switch (item.getItemId()) {
case R.id.edit_exercise:
//Edit Exercise name
mApp.setCurrentExerciseDialogStatus(DialogStatus.EDIT);
editExercise((int) info.id);
return true;
case R.id.delete_exercise:
//Delete Exercise and all its entries
deleteExercise((int) info.id);
return true;
default:
return super.onContextItemSelected(item);
}
}
/*
* (non-Javadoc)
*
* @see android.app.Activity#onCreateOptionsMenu(android.view.Menu)
*/
@Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.types_menu, menu);
return true;
}
/*
* (non-Javadoc)
*
* @see android.app.Activity#onOptionsItemSelected(android.view.MenuItem)
*/
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.add_exercise:
mApp.setCurrentExerciseDialogStatus(DialogStatus.ADD);
showDialog(DIALOG_ADD_EXERCISE);
break;
case R.id.home: // Go Back to local website
Intent myIntent3 = new Intent(ShowExercisesListActivity.this, AndroidApp.class);
ShowExercisesListActivity.this.startActivity(myIntent3);
return true;
case R.id.close: // Close WebView
Intent intent = new Intent(Intent.ACTION_MAIN);
intent.addCategory(Intent.CATEGORY_HOME);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(intent);
return true;
case R.id.google: // Open new WebView with the e.g. Google Url
startActivity(new Intent(Intent.ACTION_VIEW,
Uri.parse("http://vk.com/gymtraining")));
return true;
default:
break;
}
return super.onOptionsItemSelected(item);
}
/* (non-Javadoc)
* @see android.app.Activity#onCreateDialog(int)
*/
@Override
protected Dialog onCreateDialog(int id) {
Dialog dialog;
switch (id) {
case DIALOG_ADD_EXERCISE:
AlertDialog.Builder builder;
//build the dialog
builder = new AlertDialog.Builder(mContext);
builder.setView(mAddExerciseDialogLayout);
builder.setMessage(this.getString(R.string.add_exercise_title))
.setCancelable(false)
.setPositiveButton(this.getString(R.string.add, this.getString(R.string.exercise)), null)
.setNegativeButton("Отмена", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
dialog.cancel();
}
});
dialog = builder.create();
break;
default:
dialog = null;
break;
}
return dialog;
}
/* (non-Javadoc)
* @see android.app.Activity#onPrepareDialog(int, android.app.Dialog)
*/
@Override
protected void onPrepareDialog(int id, Dialog dialog) {
AlertDialog alertDialog = (AlertDialog) dialog;
Button positiveButton = null;
switch (id) {
case DIALOG_ADD_EXERCISE:
switch (mApp.getCurrentExerciseDialogStatus()) {
case DEFAULT:
case ADD:
alertDialog.setMessage(this.getString(R.string.add_exercise_title));
alertDialog.setButton(DialogInterface.BUTTON_POSITIVE, this.getString(R.string.add, this.getString(R.string.exercise)), new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
//Insert the new data into db
String typeName = exerciseName.getText().toString();
Exercise newExercise = DBUtil.insertExercise(mContext, typeName);
Toast.makeText(mContext, mContext.getResources().getString(R.string.exercise_saved), Toast.LENGTH_SHORT).show();
mArrayAdapter.add(newExercise);
mArrayAdapter.notifyDataSetChanged();
}
});
positiveButton = alertDialog.getButton(DialogInterface.BUTTON_POSITIVE);
positiveButton.setText(this.getString(R.string.add, this.getString(R.string.exercise)));
positiveButton.invalidate();
exerciseName.setText("");
break;
case EDIT:
alertDialog.setMessage(this.getString(R.string.edit, this.getString(R.string.exercise)));
alertDialog.setButton(DialogInterface.BUTTON_POSITIVE, this.getString(R.string.edit_button), new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
//Update the data into db
Exercise exerciseToEdit = (Exercise) exerciseName.getTag();
exerciseToEdit.setName(exerciseName.getText().toString());
DBUtil.updateExercise(mContext, exerciseToEdit);
Toast.makeText(mContext, mContext.getResources().getString(R.string.exercise_saved), Toast.LENGTH_SHORT).show();
mArrayAdapter.notifyDataSetChanged();
}
});
Exercise exerciseToEdit = (Exercise) exerciseName.getTag();
exerciseName.setText(exerciseToEdit.getName());
positiveButton = alertDialog.getButton(DialogInterface.BUTTON_POSITIVE);
positiveButton.setText(this.getString(R.string.edit_button));
positiveButton.invalidate();
break;
}
default:
break;
}
}
/**
* Edit Exercise name
*
* @param id
*/
private void editExercise(int position) {
exerciseName.setTag(mExercises.get(position));
showDialog(DIALOG_ADD_EXERCISE);
}
/**
* Delete an Exercise
*
* @param position
*/
private void deleteExercise(int position) {
Exercise exercise = mExercises.get(position);
DBUtil.deleteExercise(mContext, exercise.getId());
Toast.makeText(mContext, mContext.getResources().getString(R.string.exercise_deleted), Toast.LENGTH_SHORT).show();
mArrayAdapter.remove(exercise);
mArrayAdapter.notifyDataSetChanged();
}
}