Android RecyclerView：notifyDataSetChanged() IllegalStateException

Question

I'm trying to update the items of a recycleview using notifyDataSetChanged().

This is my onBindViewHolder() method in the recycleview adapter.

@Override
public void onBindViewHolder(ViewHolder viewHolder, int position) {

     //checkbox view listener
    viewHolder.getCheckbox().setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
        @Override
        public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {

            //update list items
            notifyDataSetChanged();
        }
    });
}

What I want to do is update the list items, after I check a checkbox. I get an illegal exception though: "Cannot call this method while RecyclerView is computing a layout or scrolling"

java.lang.IllegalStateException: Cannot call this method while RecyclerView is computing a layout or scrolling
    at android.support.v7.widget.RecyclerView.assertNotInLayoutOrScroll(RecyclerView.java:1462)
    at android.support.v7.widget.RecyclerView$RecyclerViewDataObserver.onChanged(RecyclerView.java:2982)
    at android.support.v7.widget.RecyclerView$AdapterDataObservable.notifyChanged(RecyclerView.java:7493)
    at android.support.v7.widget.RecyclerView$Adapter.notifyDataSetChanged(RecyclerView.java:4338)
    at com.app.myapp.screens.RecycleAdapter.onRowSelect(RecycleAdapter.java:111)

I also used notifyItemChanged(), same exception. Any secret way to update to notify the adapter that something changed?

Answer 1

You should move method 'setOnCheckedChangeListener()' to ViewHolder which is inner class on your adapter.

onBindViewHolder() is not a method that initialize ViewHolder . This method is step of refresh each recycler item. When you call notifyDataSetChanged() , onBindViewHolder() will be called as the number of each item times.

So If you notifyDataSetChanged() put into onCheckChanged() and initialize checkBox in onBindViewHolder() , you will get IllegalStateException because of circular method call.

click checkbox -> onCheckedChanged() -> notifyDataSetChanged() -> onBindViewHolder() -> set checkbox -> onChecked...

Simply, you can fix this by put one flag into Adapter.

try this,

private boolean onBind;

public ViewHolder(View itemView) {
    super(itemView);
    mCheckBox = (CheckBox) itemView.findViewById(R.id.checkboxId);
    mCheckBox.setOnCheckChangeListener(this);
}

@Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
    if(!onBind) {
        // your process when checkBox changed
        // ...

        notifyDataSetChanged();
    }
}

...

@Override
public void onBindViewHolder(YourAdapter.ViewHolder viewHolder, int position) {
    // process other views 
    // ...

    onBind = true;
    viewHolder.mCheckBox.setChecked(trueOrFalse);
    onBind = false;
}

Answer 2

You can just reset the previous listener before you make changes and you won't get this exception.

private CompoundButton.OnCheckedChangeListener checkedListener = new CompoundButton.OnCheckedChangeListener() {                      
                        @Override
                        public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                            //Do your stuff
                    });;

    @Override
    public void onBindViewHolder(final ViewHolder holder, final int position) {
        holder.checkbox.setOnCheckedChangeListener(null);
        holder.checkbox.setChecked(condition);
        holder.checkbox.setOnCheckedChangeListener(checkedListener);
    }

Answer 3

使用Handler添加项目并从该Handler调用notify...()为我解决了这个问题。

Answer 4

I don't know well, but I also had same problem. I solved this by using onClickListner on checkbox

viewHolder.mCheckBox.setOnClickListener(new OnClickListener() {
        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            if (model.isCheckboxBoolean()) {
                model.setCheckboxBoolean(false);
                viewHolder.mCheckBox.setChecked(false);
            } else {
                model.setCheckboxBoolean(true);
                viewHolder.mCheckBox.setChecked(true);
            }
            notifyDataSetChanged();
        }
    });

Try this, this may help!

Answer 5

protected void postAndNotifyAdapter(final Handler handler, final RecyclerView recyclerView, final RecyclerView.Adapter adapter) {
        handler.post(new Runnable() {
            @Override
            public void run() {
                if (!recyclerView.isComputingLayout()) {
                    adapter.notifyDataSetChanged();
                } else {
                    postAndNotifyAdapter(handler, recyclerView, adapter);
                }
            }
        });
    }

Answer 6

Found a simple solution -

public class MyAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder>{

    private RecyclerView mRecyclerView; 

    @Override
    public void onAttachedToRecyclerView(RecyclerView recyclerView) {
        super.onAttachedToRecyclerView(recyclerView);
        mRecyclerView = recyclerView;
    }

    private CompoundButton.OnCheckedChangeListener checkedChangeListener 
    = (compoundButton, b) -> {
        final int position = (int) compoundButton.getTag();
        // This class is used to make changes to child view
        final Event event = mDataset.get(position);
        // Update state of checkbox or some other computation which you require
        event.state = b;
        // we create a runnable and then notify item changed at position, this fix crash
        mRecyclerView.post(new Runnable() {
            @Override public void run() {
                notifyItemChanged(position));
            }
        });
    }
}

Here we create a runnable to notifyItemChanged for a position when recyclerview is ready to handle it.

Answer 7

When you have the Message Error:

Cannot call this method while RecyclerView is computing a layout or scrolling

Simple, Just do what cause the Exception in:

RecyclerView.post(new Runnable() {
    @Override
    public void run() {
        /** 
        ** Put Your Code here, exemple:
        **/
        notifyItemChanged(position);
    }
});

Answer 8

At first I thought Moonsoo's answer (the accepted answer) wouldn't work for me because I cannot initialize my setOnCheckedChangeListener() in the ViewHolder constructor because I need to bind it each time so it gets an updated position variable. But it took me a long time to realize what he was saying.

Here is an example of the "circular method call" he is talking about:

public void onBindViewHolder(final ViewHolder holder, final int position) {
    SwitchCompat mySwitch = (SwitchCompat) view.findViewById(R.id.switch);
    mySwitch.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
                @Override
                public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                       if (isChecked) {
                           data.delete(position);
                           notifyItemRemoved(position);
                           //This will call onBindViewHolder, but we can't do that when we are already in onBindViewHolder!
                           notifyItemRangeChanged(position, data.size());
                       }
                   }
            });
    //Set the switch to how it previously was.
    mySwitch.setChecked(savedSwitchState); //If the saved state was "true", then this will trigger the infinite loop.
}

The only problem with this, is that when we need to initialize the switch to be on or off (from past saved state, for example), it is calling the listener which might call nofityItemRangeChanged which calls onBindViewHolder again. You cannot call onBindViewHolder when you are already in onBindViewHolder ], because you cannot notifyItemRangeChanged if you are already in the middle of notifying that the item range has changed. But I only needed to update the UI to show it on or off, not wanting to actually trigger anything.

Here is the solution I learned from JoniDS's answer that will prevent the infinite loop. As long as we set the listener to "null" before we set Checked, then it will update the UI without triggering the listener, avoiding the infinite loop. Then we can set the listener after.

JoniDS's code:

holder.checkbox.setOnCheckedChangeListener(null);
holder.checkbox.setChecked(condition);
holder.checkbox.setOnCheckedChangeListener(checkedListener);

Full solution to my example:

public void onBindViewHolder(final ViewHolder holder, final int position) {
    SwitchCompat mySwitch = (SwitchCompat) view.findViewById(R.id.switch);

    //Set it to null to erase an existing listener from a recycled view.
    mySwitch.setOnCheckedChangeListener(null);

    //Set the switch to how it previously was without triggering the listener.
    mySwitch.setChecked(savedSwitchState); //If the saved state was "true", then this will trigger the infinite loop.

    //Set the listener now.
    mySwitch.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
        @Override
        public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
            if (isChecked) {
                data.delete(position);
                notifyItemRemoved(position);
                //This will call onBindViewHolder, but we can't do that when we are already in onBindViewHolder!
                notifyItemRangeChanged(position, data.size());
            }
        }
    });
}

Answer 9

your CheckBox item is in changing drawable when you call notifyDataSetChanged(); so this exception would be occurred. Try call notifyDataSetChanged(); in post of your view. For Example:

buttonView.post(new Runnable() {
                    @Override
                    public void run() {
                        notifyDataSetChanged();
                    }
                });

Answer 10

Why not checking the RecyclerView.isComputingLayout() state as follows?

public class MyAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder>{

    private RecyclerView mRecyclerView; 

    @Override
    public void onAttachedToRecyclerView(RecyclerView recyclerView) {
        super.onAttachedToRecyclerView(recyclerView);
        mRecyclerView = recyclerView;
    }

    @Override
    public void onBindViewHolder(ViewHolder viewHolder, int position) {

        viewHolder.getCheckbox().setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                if (mRecyclerView != null && !mRecyclerView.isComputingLayout()) {
                    notifyDataSetChanged();
                }
            }
        });
    }
}

Answer 11

While item is being bound by the layout manager, it is very likely that you are setting the checked state of your checkbox, which is triggering the callback.

Of course this is a guess because you did not publish the full stack trace.

You cannot change adapter contents while RV is recalculating the layout. You can avoid it by not calling notifyDataSetChanged if item's checked state is equal to the value sent in the callback (which will be the case if calling checkbox.setChecked is triggering the callback).

Answer 12

Use onClickListner on checkbox instead of OnCheckedChangeListener, It will solve the problem

viewHolder.myCheckBox.setOnClickListener(new OnClickListener() {
        @Override
        public void onClick(View v) {
            if (viewHolder.myCheckBox.isChecked()) {
                // Do something when checkbox is checked
            } else {
                // Do something when checkbox is unchecked                
            }
            notifyDataSetChanged();
        }
    });

Answer 13

在notifyDataSetChanged()之前，只需使用此方法检查： recyclerView.IsComputingLayout()

Answer 14

Simple use Post:

new Handler().post(new Runnable() {
        @Override
        public void run() {
                mAdapter.notifyItemChanged(mAdapter.getItemCount() - 1);
            }
        }
    });

Answer 15

I suffered with this problem for hour and this is how you can fix it. But before you began there are some conditions to this solution.

MODEL CLASS

public class SelectUserModel {

    private String userName;
    private String UserId;
    private Boolean isSelected;


    public String getUserName() {
        return userName;
    }

    public void setUserName(String userName) {
        this.userName = userName;
    }

    public String getUserId() {
        return UserId;
    }

    public void setUserId(String userId) {
        UserId = userId;
    }

    public Boolean getSelected() {
        return isSelected;
    }

    public void setSelected(Boolean selected) {
        isSelected = selected;
    }
}

CHECKBOX in ADAPTER CLASS

CheckBox cb;

ADAPTER CLASS CONSTRUCTOR & LIST OF MODEL

private List<SelectUserModel> userList;

public StudentListAdapter(List<SelectUserModel> userList) {
        this.userList = userList;

        for (int i = 0; i < this.userList.size(); i++) {
            this.userList.get(i).setSelected(false);
        }
    }

ONBINDVIEW [Please use onclick in place of onCheckChange]

public void onBindViewHolder(@NonNull final StudentListAdapter.ViewHolder holder, int position) {
    holder.cb.setChecked(user.getSelected());
    holder.cb.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {

            int pos = (int) view.getTag();
            Log.d(TAG, "onClick: " + pos);
            for (int i = 0; i < userList.size(); i++) {
                if (i == pos) {
                    userList.get(i).setSelected(true);
// an interface to listen to callbacks
                    clickListener.onStudentItemClicked(userList.get(i));
                } else {
                    userList.get(i).setSelected(false);
                }
            }
            notifyDataSetChanged();
        }
    });

}

Answer 16

I ran into this exact issue! After Moonsoo's answer didn't really float my boat, I messed around a bit and found a solution that worked for me.

First, here's some of my code:

    @Override
    public void onBindViewHolder(ViewHolder holder, final int position) {

    final Event event = mDataset.get(position);

    //
    //  .......
    //

    holder.mSwitch.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
        @Override
        public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
            event.setActive(isChecked);
            try {
                notifyItemChanged(position);
            } catch (Exception e) {
                Log.e("onCheckChanged", e.getMessage());
            }
        }
    });

You'll notice I'm specifically notifying the adapter for the position I'm changing, instead of the entire dataset like you're doing. That being said, although I can't guarantee this will work for you, I resolved the problem by wrapping my notifyItemChanged() call in a try/catch block. This simply caught the exception, but still allowed my adapter to register the state change and update the display!

Hope this helps someone!

EDIT: I'll admit, this probably is not the proper/mature way of handle the issue, but since it doesn't appear to be causing any problems by leaving the exception unhandled, I thought I'd share in case it was good enough for someone else.

Answer 17

This is happening because you're probably setting the 'listener' before you configure the value for that row, which makes the listener to get triggered when you 'configure the value' for the checkbox.

What you need to do is:

@Override
public void onBindViewHolder(YourAdapter.ViewHolder viewHolder, int position) {
   viewHolder.mCheckBox.setOnCheckedChangeListener(null);
   viewHolder.mCheckBox.setChecked(trueOrFalse);
   viewHolder.setOnCheckedChangeListener(yourCheckedChangeListener);
}

Answer 18

        @Override
        public void onBindViewHolder(final MyViewHolder holder, final int position) {
            holder.textStudentName.setText(getStudentList.get(position).getName());
            holder.rbSelect.setChecked(getStudentList.get(position).isSelected());
            holder.rbSelect.setTag(position); // This line is important.
            holder.rbSelect.setOnClickListener(onStateChangedListener(holder.rbSelect, position));

        }

        @Override
        public int getItemCount() {
            return getStudentList.size();
        }
        private View.OnClickListener onStateChangedListener(final RadioButton checkBox, final int position) {
            return new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    if (checkBox.isChecked()) {
                        for (int i = 0; i < getStudentList.size(); i++) {

                            getStudentList.get(i).setSelected(false);

                        }
                        getStudentList.get(position).setSelected(checkBox.isChecked());

                        notifyDataSetChanged();
                    } else {

                    }

                }
            };
        }

Answer 19

simply use isPressed() method of CompoundButton in onCheckedChanged(CompoundButton compoundButton, boolean isChecked)
eg

public void onCheckedChanged(CompoundButton compoundButton, boolean isChecked) {   
                      ... //your functionality    
                            if(compoundButton.isPressed()){
                                notifyDataSetChanged();
                            }
                        }  });

Answer 20

I had the same problem using the Checkbox and the RadioButton. Replacing notifyDataSetChanged() with notifyItemChanged(position) worked. I added a Boolean field isChecked to the data model. Then I updated the Boolean value and in onCheckedChangedListener , I called notifyItemChanged(adapterPosition) . This might not be the best way, but worked for me. The boolean value is used for checking whether the item is checked.

Answer 21

mostly it happen beacause notifydatasetchanged calling onCheckedchanged event of checkbox and in that event again there is notifydatasetchanged .

to solve it you can just check that checkbox is checked by programatically or user pressed it. there is method isPressed for it.

so wrap whole listner code inside isPressed method. and its done.

 holder.mBinding.cbAnnual.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(CompoundButton compoundButton, boolean b) {

                if(compoundButton.isPressed()) {


                       //your code
                        notifyDataSetChanged();   

            }
        });

Answer 22

 override fun bindItemViewHolder(viewHolder: RecyclerView.ViewHolder, position: Int) {
    var item: ThingChannels = items[position]
    rowActionBinding.xCbChannel.text = item.channelType?.primaryType
    rowActionBinding.xTvRoomName.text = item.thingDetail?.room?.name
    rowActionBinding.xCbChannel.isChecked = item.isSelected
    rowActionBinding.xCbChannel.tag = position
    rowActionBinding.xCbChannel.setOnClickListener {
        setSelected(it.tag as Int)
        if (onItemClickListener != null) {
            onItemClickListener!!.onItemClick(position, null)
        }
    }
}

Answer 23

None of the answers solve the problem!

All of them either suggest using recylerView.post() which gives me the same crash or swallow the change (ie not notify the adapter of the change) if the user is scrolling. This just means that if the user was scrolling when the change was ready, they will never see the change.

The answer

Listen for when the user stops scrolling using RecyclerView.OnScrollListener and then notify the adapter:

recyclerView.addOnScrollListener(object : RecyclerView.OnScrollListener() {
    override fun onScrollStateChanged(
        recyclerView: RecyclerView,
        newState: Int
    ) {
        if(newState == RecyclerView.SCROLL_STATE_IDLE) recyclerViewAdapter.notifyDataSetChanged()
    }
})

Answer 24

For me problem occurred when I exited from EditText by Done, Back, or outside input touch. This causes to update model with input text, then refresh recycler view via live data observing.

The Problem was that cursor/focus remain in EditText.

When I have deleted focus by using:

editText.clearFocus() 

Notify data changed method of recycler view did stop throwing this error.

I think this is one of the possible reason/solutions to this problem. It is possible that this exception can be fixed in another way as it can be caused by totally different reason.