When i try to remove a specific item from a list View:
buyButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
tempToken -= selPerk.cost;
plrPerks.add(selPerk);
String tokStr = String.valueOf(tempToken);
tkn.setText(tokStr);
shopItems.remove(selPerk);
selPerk = new Perk();
perkDialog.dismiss();
}
});
It always seems to remove the last item. This is where i open the dialog:
perks.setClickable(true);
perks.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> arg0, View arg1,
int position, long arg3) {
Perk perk = (Perk) perks.getItemAtPosition(position);
showItem(perk);
}
});
}
This is the show Item function:
public void showItem(Perk perk) {
if (tempToken >= perk.cost) {
selPerk = perk;
How do i remove a specific item from a list and list view respectively?
Thanks for your time :)
In "setOnItemClickListener" listener, you are getting the perk object. So you can remove that object from your list like this-
shopItems.remove(perk);
and then you can call-
your_adapter.notifyDataSetChanged();
to refresh your listview.
To remove a specific item from a list view, your can call removeView(View toBeRemoved) if you have a reference to the view you wish to remove. If you have the index, you can call removeView(int index).
http://developer.android.com/reference/android/widget/ListView.html
You can remove a specific item from a list in the same way, using remove(Object item) or remove(int index).
http://docs.oracle.com/javase/7/docs/api/java/util/List.html
Hope this helps!
I fixed it. Whenever i removed an item i had to do it like so:
shopItems.remove(selPerk);
perk_adapter.notifyDataSetChanged();
So i had to notify my listeview adapter that i removed an item.
Related
I have added Spinner inside RecyclerView , when i am trying to get spinner selected item data, its getting another/wrong position data, any one suggest me to get correct selected item and position from Spinner onItemSelected
Here is my code
#Override
public void onBindViewHolder(final QuestionHolder holder, final int position) {
if (position % 2 == 1)
holder.itemView.setBackgroundColor(Color.parseColor("#F8F8F8"));
adapter = new ArrayAdapter<Option>(binding.getRoot().getContext(),
R.layout.item_spinner, questionList.get(position).getOptions());
adapter.setDropDownViewResource(R.layout.item_spinner);
binding.optionSpinner.setAdapter(adapter);
binding.serialNo.setText((position + 1) + ".");
binding.setQuestion(questionList.get(position));
binding.executePendingBindings();
binding.optionSpinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
#Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
Toast.makeText(holder.itemView.getContext(), position+" : "+binding.optionSpinner.getSelectedItem().toString(), Toast.LENGTH_SHORT).show();
spinnerData.setSelectedData(position, binding.optionSpinner.getSelectedItem().toString());
}
#Override
public void onNothingSelected(AdapterView<?> parent) {
}
});
}
I think you have to try this
showSpinnerList.setOnItemSelectedListener(new
AdapterView.OnItemSelectedListener() {
#Override
public void onItemSelected(AdapterView<?> parent, View view, int
position, long id) {
// On selecting a spinner item
String item = parent.getItemAtPosition(position).toString();
}
#Override
public void onNothingSelected(AdapterView<?> parent) {
// todo for nothing selected
}
});
Check this, can be helpful and may fix your problem. If this won't fix your problem at least you get rid of Lint error. Lint error “Do not treat position as fixed; only use immediately…”. So everywhere you are using final int position** change it to getAdapterPosition();
The documentation of RecyclerView.Adapter.onBindViewHolder()
states:
Note that unlike ListView, RecyclerView will not call this method
again if the position of the item changes in the data set unless the
item itself is invalidated or the new position cannot be determined.
For this reason, you should only use the position parameter while
acquiring the related data item inside this method and should not keep
a copy of it. If you need the position of an item later on (e.g. in a
click listener), use getAdapterPosition() which will have the updated
adapter position
So, technically items may be re-arranged and binding will not be
necessary because items are not invalidated yet. The position
variable received holds true only for the scope of bind function and
will not always point to correct position in the data set. That's why
the function getAdapterPosition() must be called everytime updated
position is needed.
IMHO, mLastPosition = holder.getAdapterPosition(); is still
potentially wrong. Because item may be re-arranged and mLastPosition
still points to old position.
About why lint is silent, perhaps Lint rule is not that thorough. Its
only checking whether position parameter is being copied or not.
in my Android app I have created a ListView component called myList, and filled it with objects of my own custom type:
class MyClass{
private String displayName;
private String theValue;
... //here constructor, getters, setters and toString() are implemented
}
I used the ArrayAdapter to bound the ArrayList theObjects with myList:
ArrayAdapter<MyClass> adapter=
new ArrayAdapter<MyClass>(this, R.layout.lay_item, theObjects);
myList.setAdapter(adapter);
This works fine, the list is populated and etc., but when I'm trying to access the selected item, i receive a Null object. I've done this using
myList.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> adapter, View v, int position, long id) {
MyClass selItem = (MyClass) myList.getSelectedItem(); //
String value= selItem.getTheValue(); //getter method
}
What seems to be the problem? Thank you
By default, when you click on a ListView item it doesn't change its state to "selected". So, when the event fires and you do:
myList.getSelectedItem();
The method doesn't have anything to return. What you have to do is to use the position and obtain the underlying object by doing:
myList.getItemAtPosition(position);
You are implementing the Click Handler rather than Select Handler. A List by default doesn't suppose to have selection.
What you should change, in your above example, is to
public void onItemClick(AdapterView<?> adapter, View v, int position, long id) {
MyClass item = (MyClass) adapter.getItem(position);
}
Since the onItemClickLitener() will itself provide you the index of the selected item, you can simply do a getItemAtPosition(i).toString(). The code snippet is given below :-
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
String s = listView.getItemAtPosition(i).toString();
Toast.makeText(activity.getApplicationContext(), s, Toast.LENGTH_LONG).show();
adapter.dismiss(); // If you want to close the adapter
}
});
On the method above, the i parameter actually gives you the position of the selected item.
On onItemClick :
String text = parent.getItemAtPosition(position).toString();
myList.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> adapter, View v, int position, long id) {
MyClass selItem = (MyClass) adapter.getItem(position);
}
}
Using setOnItemClickListener is the correct answer, but if you have a keyboard you can change selection even with arrows (no click is performed), so, you need to implement also setOnItemSelectedListener :
myListView.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
#Override
public void onItemSelected(AdapterView<?> adapterView, View view, int position, long l) {
MyObject tmp=(MyObject) adapterView.getItemAtPosition(position);
}
#Override
public void onNothingSelected(AdapterView<?> adapterView) {
// your stuff
}
});
In touch mode, there is no focus and no selection. Your UI should use a different type of widget, such as radio buttons, for selection.
The documentation on ListView about this is terrible, just one obscure mention on setSelection.
Though I am using kotlin, the following code answered your question. This return selected item:
val item = myListView.adapter.getItem(i).toString()
The following is the whole selecteditem Listener
myListView.setOnItemClickListener(object : OnItemClickListener {
override fun onItemClick(parent: AdapterView<*>, view: View, i: Int,
id: Long) {
val item = myListView.adapter.getItem(i).toString()
}
})
The code returns the item clicked by its index i as shown in the code
MyClass selItem = (MyClass)
myList.getSelectedItem(); //
You never instantiated your class.
I have an auto-complete drop down list, I want to make some action when I click on one item in the list.. is there any listener or event handler to to this ??
use this, this will provide you method called setOnItemClickListener().
private AdapterView.OnItemClickListener searchItemClicked = new AdapterView.OnItemClickListener()
{
public void onItemClick(AdapterView<?> parent, View view, int position, long id)
{
//your code here
}
}
It's important to note that OnItemSelectedListener does not activate when a user selects a dropdown.
I have a listview in my program. the problem is that. the list is in single choice mode and when i select any item i have 4 buttons on the footer of my page for that item.. alll i want is to know that. how can i keep that item selected and while cliking any button i can get the selected item.
Try this:
listView.setOnItemSelectedListener(new OnItemSelectedListener() {
public void onItemSelected(AdapterView a, View v, int position, long l) {
arrayPosition=position;
}
public void onNothingSelected(AdapterView<?> arg0) {
}
});
where arrayPosition is a static integer variable.
Try this if it helps..
If you are using a ListActivity you can use getSelectedItemId() or getSelectedItemPosition(). Alternatively you can bind your own OnItemClickListener to the ListView object. More information can be found in this tutorial.
It appears that android's Spinner class (and possibly ListView in general, although I don't know for sure) calls your OnItemSelectedListener's onItemSelected() method after you call setAdapter(), even if the user hasn't explicitly selected anything yet.
I can see how this would be useful in many situations, but there are times when I only want onItemSelected() to be called when an item is actually specifically selected.
Is there a way to control this behaviour and have Spinner NOT call onItemSelected() after setting the adapter?
I haven't used this solution for very long yet so I'm not totally confident that it works as expected, but I've had luck so far with this workaround:
spinner.setOnItemSelectedListener( new OnItemSelectedListener() {
protected Adapter initializedAdapter = null;
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
// Always ignore the initial selection performed after setAdapter
if( initializedAdapter !=parent.getAdapter() ) {
initializedAdapter = parent.getAdapter();
return;
}
...
}
}
Is there a better way?
Add listener to spinner like below:
spinner.post(new Runnable(){
public void run()
{
spinner.setOnItemSelectedListener( new OnItemSelectedListener() {
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
...
}
}
}
});
I've used the setTag and getTag methods, and created a resource id called "spinnerstate".
Then whenever I programmatically set the adapter, I set the "spinnerstate" tag to "init", and in the fired event, set it to "ready" and ignore the event. (note my code is Mono for Android se it will look different):
Set Adapter:
profileSpn.SetTag (Resource.Id.spinnerstate, "init");
profileSpn.Adapter = new ArrayAdapter (this, Android.Resource.Layout.SimpleSpinnerItem, items.ToArray ());
Item Selected event:
string state = (string)((Spinner)sender).GetTag (Resource.Id.spinnerstate);
if (state == "init") {
((Spinner)sender).SetTag (Resource.Id.spinnerstate, "ready");
return;
}
I agree that this is not desired behaviour in almost 100% of cases, and I don't think it's good design on the part of Google, but there you go.
I did similar things before, I used count value. Using parent adapter object is incomplete because it can be a problem when view is refreshed or getView() called again.
Therefore, I recommend that using array of counter.
At first, define array of count in adapter globally.
private int isInitializedView[];
And then initialize it on getView().
isInitializedView[position] = 0;
In the selection listener, do something that you want if it already initialized.
holder.mySpinner.setOnItemSelectedListener(new OnItemSelectedListener() {
#Override
public void onItemSelected(AdapterView<?> parentView, View selectedItemView, int position, long id) {
isInitializedView[position]++;
if(isInitializedView[position] > 1) {
// do someting that you want
}
}
#Override
public void onNothingSelected(AdapterView<?> parentView) {}
});
(Note that isInitializedView[position]++; can be come after if() routine, and only trigger event when this value is >0 . It's your choice.)
I had three spinner in my activity and all spinner adapter data has been filled at runtime(from web-service data after call from onCreate method). So it automatically call onItemSelected(AdapterView<?> parent, View view, int position, long id) method of spinner.
I solved this issue by using onUserInteraction() method of activity
check this method that user is interacting with spinner or not. if yes then perform the action else not
Declare isUserIntract boolean variable globally
in onItemSelected method use following procedure
If(isUserIntract)
{
//perform Action
}
else{
//not perform action
}
use below code in activity
#Override
public void onUserInteraction() {
super.onUserInteraction();
isUserIntract = true;
}