所以我看过Delete Sharedpreferences on button click的这篇文章，并尝试了代码，但是当我在应用程序上运行它时，只有我的textview消失了，其他一切都保留了吗？
这是代码段：（这是溢出菜单上的一个按钮）
else if (id == R.id.action_delete) {
//code to delete list here.
SharedPreferences.Editor editor = getSharedPreferences(MY_PREFS_NAME, MODE_PRIVATE).edit();
editor.clear().apply();
Toast.makeText(getBaseContext(), "List removed.", Toast.LENGTH_SHORT).show();
return true;
}
我的完整代码
public class create extends AppCompatActivity {
private LinearLayout mLinearLayout;
private ArrayList<SearchableSpinner> mSpinners;
private List<AppCompatButton> mButtons = new ArrayList<>();
private List<CheckBox> mCheckboxes = new ArrayList<>();
private List<TextView> mTextviews = new ArrayList<>();
private List<EditText> mEdittexts = new ArrayList<>();
private List<View> mViews = new ArrayList<>();
private Map<String, String> numberItemValues = new HashMap<>();
private Spinner spinner;
private TextView textview;
private CheckBox checkbox;
List<String> itemList = new ArrayList<>();
LinearLayout verticallayout,horizontalLayout;
public static final String MY_PREFS_NAME = "MyPrefsFile";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_create);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
findViewById(R.id.my_linearLayout).requestFocus();
verticallayout = findViewById(R.id.verticalLayout); //got
//Arrays
ArrayList<String> items = new ArrayList<>();
items.add(String.valueOf(mSpinners)); // add you selected item
mSpinners = new ArrayList<>();
//Initializing Variables Here
mLinearLayout = findViewById(R.id.my_linearLayout);
//verticallayout = findViewById(R.id.verticalLayout);
textview = findViewById(R.id.textview);
checkbox = findViewById(R.id.checkbox);
//TODO getting shared prefs on create
SharedPreferences prefs = getSharedPreferences(MY_PREFS_NAME, MODE_PRIVATE);
try {
JSONArray jsonArray2 = new JSONArray(prefs.getString("key", null));
for (int i = 0; i < jsonArray2.length(); i++) {
final Spinner spinner = makeSpinner();
mLinearLayout.addView(spinner);
final View newView = makeView();
//Add a new view
mLinearLayout.addView(newView);
mViews.add(newView);
/* final EditText newEdittext = makeEdittext();
mLinearLayout.addView(newEdittext);
mEdittexts.add(newEdittext);
final CheckBox newCheckbox = makeCheckbox();
mLinearLayout.addView(newCheckbox);
//TODO add checkbox to your list
mCheckboxes.add(newCheckbox);*/
createRow();
final TextView newTextview = makeTextview();
mLinearLayout.addView(newTextview);
mTextviews.add(newTextview);
final int listSize = mViews.size();
//TODO deleting item
horizontalLayout.setOnClickListener(new View.OnClickListener() {
//start
@Override
public void onClick(View view) {
//when the 'new button' is pressed, alert shows if you are sure you want to delete the item or not.
final View.OnClickListener context = this;
AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(create.this);
// set title
alertDialogBuilder.setTitle("Delete Item");
// set dialog message
alertDialogBuilder
.setMessage("Are you sure you want to delete this item?")
.setCancelable(false)
.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
// if this button is clicked, close
// current activity
if (listSize > 0) {
//mCheckboxes.get(listSize - 1).setVisibility(View.GONE);
mSpinners.get(listSize - 1).setVisibility(View.GONE);
// mSpinners.remove(listSize - 1);
mViews.get(listSize - 1).setVisibility(View.GONE);
mTextviews.get(listSize - 1).setVisibility(View.GONE);
// mEdittexts.get(listSize - 1).setVisibility(View.GONE);
Toast.makeText(getBaseContext(), "Item removed.", Toast.LENGTH_SHORT).show();
}
}
})
.setNegativeButton("No", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
// if this button is clicked, just close
// the dialog box and do nothing
dialog.cancel();
}
});
// create alert dialog
AlertDialog alertDialog = alertDialogBuilder.create();
// show it
alertDialog.show();
}
});
int positionOfSpinner = (int) jsonArray2.get(i);
spinner.setSelection(positionOfSpinner);
}
} catch (Exception e) {
e.printStackTrace();
}
//end of shared pref code
//TODO FAB BUTTON
FloatingActionButton floatingActionButton =
(FloatingActionButton) findViewById(R.id.fab);
floatingActionButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Toast.makeText(getBaseContext(), "Item added!", Toast.LENGTH_SHORT).show();
spinner = findViewById(R.id.spinner);
// Handle ze click.
final Spinner spinner = makeSpinner();
mLinearLayout.addView(spinner);
LinearLayout.LayoutParams layoutParams = (LinearLayout.LayoutParams) spinner.getLayoutParams();
layoutParams.setMargins(5, 100, 10, 0); //top 70
Resources resources = getResources();
DisplayMetrics metrics = resources.getDisplayMetrics();
layoutParams.height = (int) (70 * ((float) metrics.densityDpi / DisplayMetrics.DENSITY_DEFAULT)); //80
layoutParams.width = (int) (240 * ((float) metrics.densityDpi / DisplayMetrics.DENSITY_DEFAULT)); //240
spinner.setLayoutParams(layoutParams);
final View newView = makeView();
mLinearLayout.addView(newView);
mViews.add(newView);
/* final EditText newEdittext = makeEdittext();
mLinearLayout.addView(newEdittext);
mEdittexts.add(newEdittext);*/
createRow();
final int listSize = mViews.size();
//code for deleting the said item.
horizontalLayout.setOnClickListener(new View.OnClickListener() {
//start
@Override
public void onClick(View view) {
//when the 'new button' is pressed, alert shows if you are sure you want to delete the item or not.
final View.OnClickListener context = this;
AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(create.this);
// set title
alertDialogBuilder.setTitle("Delete Item");
// set dialog message
alertDialogBuilder
.setMessage("Are you sure you want to delete this item?")
.setCancelable(false)
.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
// if this button is clicked, close
// current activity
if (listSize > 0) {
//mCheckboxes.get(listSize - 1).setVisibility(View.GONE);
mSpinners.get(listSize - 1).setVisibility(View.GONE);
mSpinners.remove(listSize - 1);
mViews.get(listSize - 1).setVisibility(View.GONE);
mTextviews.get(listSize - 1).setVisibility(View.GONE);
//mEdittexts.get(listSize - 1).setVisibility(View.GONE);
Toast.makeText(getBaseContext(), "Item removed.", Toast.LENGTH_SHORT).show();
}
}
})
.setNegativeButton("No", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
// if this button is clicked, just close
// the dialog box and do nothing
dialog.cancel();
}
});
// create alert dialog
AlertDialog alertDialog = alertDialogBuilder.create();
// show it
alertDialog.show();
}
});
//Add a new checkbox
/* final CheckBox newCheckbox = makeCheckbox();
mLinearLayout.addView(newCheckbox);
//TODO add checkbox to your list
mCheckboxes.add(newCheckbox);*/
final TextView newTextview = makeTextview();
mLinearLayout.addView(newTextview);
mTextviews.add(newTextview);
//TODO Add the spinner on item selected listener to get selected items
spinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> parentView, View selectedItemView, int position, long id) {
String currentItem = itemList.get(position);
String aisleNumber = numberItemValues.get(currentItem);
//TODO you can use the above aisle number to add to your text view
//mTextviews.get(mTextviews.size() -1).setText(aisleNumber);
newTextview.setText(aisleNumber);
}
@Override
public void onNothingSelected(AdapterView<?> parentView) {
// code here, do nothing
}
});
}
});
}
//TODO OVERFLOW MENU
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.create_menu, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if (id == R.id.action_settings) {
/*Intent startSettingsActivity = new Intent(this, AppCompatPreferenceActivity.class);
startActivity(startSettingsActivity);
//start the settings activity here.*/
startActivity(new Intent(create.this, settings.class));
return true;
}
else if (id == R.id.action_delete) {
//code to delete list here.
SharedPreferences.Editor editor = getSharedPreferences(MY_PREFS_NAME, MODE_PRIVATE).edit();
editor.clear().apply();
Toast.makeText(getBaseContext(), "List removed.", Toast.LENGTH_SHORT).show();
return true;
}
else if (id ==R.id.action_help) {
// setup the alert builder
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setTitle("Help");
builder.setMessage("To use this app, first go to Create your Shopping List.\n" +
"Here, you can add items to your list. Once you have added all items, you can click the menu at the top right corner (or if it doesnt appear press your menu button beside your home button on your device, then click View your List.\n" +
"This will take you to the screen where you can view you shopping list with the items in aisle order to make your shop much easier.\n" +
"You can still add items at this point. Press the white background of each item to delete the item if you wish.");
// add a button
builder.setPositiveButton("OK", null);
// create and show the alert dialog
AlertDialog dialog = builder.create();
dialog.show();
return true;
}
else if (id == R.id.action_gotoview) {
//takes the size of the list of spinners, for reference
ArrayList<Integer> spinnerList = new ArrayList<>();
for(int i = 0; i < mSpinners.size(); i++) {
spinnerList.add(mSpinners.get(i).getSelectedItemPosition());
}
Bundle newBundle = new Bundle();
newBundle.putIntegerArrayList("arraylist", spinnerList);
Intent newIntent = new Intent(create.this, viewscreen.class);
newIntent.putExtra("extraBundle", newBundle);
startActivity(newIntent);
//code to go to view screen, aka intent
return true;
}
return super.onOptionsItemSelected(item);
}
public void createRow(View view){
createRow(); //got
}
private void createRow() { //got
horizontalLayout = new LinearLayout(this);
LinearLayout.LayoutParams horizontalParams = new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT);
horizontalLayout.setOrientation(LinearLayout.HORIZONTAL);
horizontalParams.height = 80;
horizontalParams.setMargins(0, 15, 0, 15); // LEFT, TOP, RIGHT, BOTTOM
horizontalLayout.setLayoutParams(horizontalParams);
horizontalLayout.setBackgroundColor(ContextCompat.getColor(this, R.color.addButtons));
makeEdittext();
makeCheckbox();
verticallayout.addView(horizontalLayout, horizontalParams);
}
//DUPLICATING ITEMS WHEN FAB IS PRESSED//
private CheckBox makeCheckbox() {
//Create new Checkbox
CheckBox checkbox = new CheckBox(this);
// Setup layout
/* LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.MATCH_PARENT,
LinearLayout.LayoutParams.WRAP_CONTENT);
//setup relative layout for the positioning of the objects
Resources resources = getResources();
DisplayMetrics metrics = resources.getDisplayMetrics();
RelativeLayout.LayoutParams relativeParams = new RelativeLayout.LayoutParams((int) (70 * ((float) metrics.densityDpi / DisplayMetrics.DENSITY_DEFAULT)), (int) (240 * ((float) metrics.densityDpi / DisplayMetrics.DENSITY_DEFAULT)));
relativeParams.addRule(RelativeLayout.RIGHT_OF, R.id.textview);
checkbox.setLayoutParams(relativeParams);
checkbox.setLayoutParams(layoutParams);*/
LinearLayout.LayoutParams checkParams = new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT);
checkParams.setMargins(10, 10, 10, 10);
checkParams.gravity = Gravity.LEFT;
checkbox.setLayoutParams(checkParams);
horizontalLayout.addView(checkbox);
return checkbox;
}
private TextView makeTextview() {
//create new textview
TextView textview = new TextView(this);
//setup layout
LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.MATCH_PARENT,
LinearLayout.LayoutParams.WRAP_CONTENT);
textview.setLayoutParams(layoutParams);
/*LinearLayout.LayoutParams editParams = new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT);
editParams.setMargins(10, 10, 10, 10);
editParams.width = 70;
editParams.height = 50;
textview.setLayoutParams(editParams);
horizontalLayout.addView(textview);*/
textview.setTextSize(30);
return textview;
}
private EditText makeEdittext() {
//create new edittext
EditText edittext = new EditText(this);
//setup layout
/* final LinearLayout.LayoutParams lparams = new LinearLayout.LayoutParams(70, 50); // Width , height
edittext.setLayoutParams(lparams);*/
LinearLayout.LayoutParams editParams = new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT);
editParams.setMargins(10, 10, 10, 10);
editParams.width = 70;
editParams.height = 50;
edittext.setLayoutParams(editParams);
horizontalLayout.addView(edittext);
edittext.setInputType(InputType.TYPE_CLASS_NUMBER | InputType.TYPE_NUMBER_FLAG_DECIMAL | InputType.TYPE_NUMBER_FLAG_SIGNED);
edittext.setHint("qty");
return edittext;
}
//set the 3d effect to view
private View makeView() {
//create new View
View view = new View(this);
view.setBackgroundColor(Color.parseColor("#ffffff"));
LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams( LinearLayout.LayoutParams.MATCH_PARENT, 100);
new LinearLayout.LayoutParams( LinearLayout.LayoutParams.WRAP_CONTENT, 50);
view.setLayoutParams(layoutParams);
view.setClickable(true);
//view.setLayoutParams(layoutParams);
//setup layout
return view;
}
private Spinner makeSpinner() {
//opens csv
InputStream inputStream = getResources().openRawResource(R.raw.shopitems);
CSVFile csvFile = new CSVFile(inputStream);
//TODO I made this variable global, declared it at the very top of this file
itemList = csvFile.read();
//Create new spinner
// SearchableSpinner spinner = (SearchableSpinner) new Spinner(this, Spinner.MODE_DROPDOWN);
SearchableSpinner spinner = new SearchableSpinner(this);
// Setup layout
/* LinearLayout.LayoutParams spinnerParams = new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT);
spinnerParams.setMargins(10, 10, 10, 10);
spinnerParams.gravity = Gravity.LEFT;
Resources resources = getResources();
DisplayMetrics metrics = resources.getDisplayMetrics();
spinnerParams.height = (int) (70 * ((float) metrics.densityDpi / DisplayMetrics.DENSITY_DEFAULT)); //80
spinnerParams.width = (int) (240 * ((float) metrics.densityDpi / DisplayMetrics.DENSITY_DEFAULT)); //240
spinner.setLayoutParams(spinnerParams);
horizontalLayout.addView(spinner);*/
LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.MATCH_PARENT,
LinearLayout.LayoutParams.WRAP_CONTENT);
spinner.setLayoutParams(layoutParams);
MyListAdapter adapter = new MyListAdapter(this, R.layout.listrow, R.id.txtid, itemList);
spinner.setAdapter(adapter);
//Add it to your list of spinners so you can retrieve their data when you click the getSpinner button
mSpinners.add(spinner);
return spinner;
}
private class CSVFile {
InputStream inputStream;
public CSVFile(InputStream inputStream) {
this.inputStream = inputStream;
}
public List<String> read() {
List<String> resultList = new ArrayList<String>();
BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
try {
String line;
while ((line = reader.readLine()) != null) {
String[] row = line.split(",");
//TODO I edited this part so that you'd add the values in our new hash map variable
numberItemValues.put(row[1], row[0]);
resultList.add(row[1]);
}
} catch (IOException e) {
Log.e("Main", e.getMessage());
} finally {
try {
inputStream.close();
} catch (IOException e) {
Log.e("Main", e.getMessage());
}
}
return resultList;
}
}
//on stop, the things are saved into shared prefs
@Override
protected void onStop () {
//public static final String MY_PREFS_NAME = "MyPrefsFile";
SharedPreferences.Editor editor = getSharedPreferences(MY_PREFS_NAME, MODE_PRIVATE).edit();
JSONArray jsonArray = new JSONArray();
for(int i = 0; i < mSpinners.size(); i++) {
jsonArray.put(mSpinners.get(i).getSelectedItemPosition());
}
editor.putString("key", jsonArray.toString());
editor.apply();
super.onStop();
}
}
答案 0 :(得分：0)
尝试以下操作清除共享的偏好设置：
else if (id == R.id.action_delete) {
//code to delete list here.
getSharedPreferences(MY_PREFS_NAME, MODE_PRIVATE).edit().clear().commit();
Toast.makeText(getBaseContext(), "List removed.", Toast.LENGTH_SHORT).show();
return true;
}