Repeat Button in RecyclerView

Question

I have a RecyclerView with a ViewHolder that contains a Button. I want the Button to be a regular single-click Button or a hold & repeat Button depending on a checkbox. Some of the components I have looked at that may be of significance are:

1. Making sure the handler is not added multiple times and is removed before adding the other one when switching between single-click and hold & repeat.
2. Using the Button's Touch event to start/stop repeating when using hold & repeat
3. Whether to use a timer, a while loop containing Task.Delay, or another method when doing hold & repeat
4. Whether to have the hold & repeat manually raise the click event, manually call the click event handler, or just use separate code (the code I need the Button to execute is very short)

Avoiding adding multiple and removing existing event handlers in the Adapter of a RecyclerView is something that I have always found somewhat challenging. Does anyone have any suggestions on how to make a Button that meets my requirements? Thanks.

Answer 1

Hello,

Welcome to our Microsoft Q&A platform!

Here is a similar demo, you can refer to the following code:

1. define the Ui in the item layout (PhotoCardView.axml)

    <LinearLayout              
        android:orientation="horizontal"  
        android:layout_width="match_parent"  
        android:layout_height="wrap_content">  
   
        <CheckBox  
   

android:text="CheckBox"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/myCheckBox" />

        <TextView  
            android:id="@+id/mNumber"  
             android:layout_width="wrap_content"  
             android:layout_height="wrap_content"/>  

        <LinearLayout  
            android:orientation="vertical"  
            android:layout_width="wrap_content"  
            android:layout_height="wrap_content">  
             <Button  
            android:text="+"  
            android:id="@+id/addBtn"  
            android:layout_width="wrap_content"  
            android:layout_height="wrap_content"/>  
                        <Button  
            android:text="-"  
            android:id="@+id/minusBtn"  
            android:layout_width="wrap_content"  
            android:layout_height="wrap_content"/>  

        </LinearLayout>  
    </LinearLayout>  

2.define a ViewHolder(mine is PhotoViewHolder.cs)

  public class PhotoViewHolder: RecyclerView.ViewHolder  
{  
     public int number { get; set; }  

    public TextView NumberTextView { get; private set; }  

     public CheckBox MyCheckBox { get; set; }  
    public Button AddButton { get; set; }  

    public Button MinusButton { get; set; }  

    public PhotoViewHolder(View itemView, Action<int> listener) : base(itemView)  
    {  

       MyCheckBox = itemView.FindViewById<CheckBox>(Resource.Id.myCheckBox);  

        // code here   
        NumberTextView = itemView.FindViewById<TextView>(Resource.Id.mNumber);  
        AddButton = itemView.FindViewById<Button>(Resource.Id.addBtn);  
        MinusButton = itemView.FindViewById<Button>(Resource.Id.minusBtn);  

        // Detect user clicks on the item view and report which item  
        // was clicked (by layout position) to the listener:  
        itemView.Click += (sender, e) => listener(base.LayoutPosition);  
        MyCheckBox.Click += delegate  
        {  
            if (MyCheckBox.Checked)  
            {  
                Console.WriteLine("I can get the adapter position here {0}", AdapterPosition);  
                IsChecked = true;  
            }  
            else  
            {  
                Console.WriteLine("I can get the adapter position here {0}", AdapterPosition);  
                IsChecked = false;  
            }  
        };  
    }  
}  

3. in your adapter (mine is PhotoAlbumAdapter.cs)

   public class PhotoAlbumAdapter: RecyclerView.Adapter  
    {  
        public event EventHandler<int> ItemClick;  
        public static List<Photo> mPhotoAlbum = new List<Photo>();  
   
        public static RecyclerView.Adapter adapter;  
   
        public PhotoAlbumAdapter(List<Photo> branchesList)  
        {  
            adapter = this;  
            mPhotoAlbum = branchesList;  
        }  
   
        public override RecyclerView.ViewHolder OnCreateViewHolder(ViewGroup parent, int viewType)  
        {  
            View itemView = LayoutInflater.From(parent.Context).Inflate(Resource.Layout.PhotoCardView, parent, false);  
   
            PhotoViewHolder vh = new PhotoViewHolder(itemView, OnClick);  
   
            return vh;  
        }  
   
        public override void OnBindViewHolder(RecyclerView.ViewHolder holder, int position)  
        {  
            PhotoViewHolder vh = holder as PhotoViewHolder;  
            //***********************  
            Photo item=   mPhotoAlbum[position];  
   
            vh.Caption.Text = item.Caption;  
   
   
            vh.MyCheckBox.SetOnCheckedChangeListener(null);  
           vh.MyCheckBox.SetOnCheckedChangeListener(new MyCheckListener(item));  
           vh.MyCheckBox.Checked = item.isChecked;  
   
            vh.AddButton.SetOnClickListener(new MyAddItem(item, position));  
            vh.MinusButton.SetOnClickListener(new MyMinusItem(item,position));  
        }  
   
   
   
        class MyAddItem : Java.Lang.Object, View.IOnClickListener  
        {  
            Photo photo;  
            int position;  
            public MyAddItem(Photo item, int position)  
            {  
                this.photo = item;  
                this.position = position;  
            }  
   
            public void OnClick(View v)  
            {  
                //add the number you want  and call NotifyDataSetChanged to update UI.  
                 photo.mNumber++;  
                adapter.NotifyDataSetChanged();  
            }  
   
   
        }  
   
   
    class MyMinusItem : Java.Lang.Object, View.IOnClickListener  
    {  
        Photo photo;  
        int position;  
        public MyMinusItem(Photo item, int position)  
        {  
            this.photo = item;  
            this.position = position;  
        }  
   
        public void OnClick(View v)  
        {  
            photo.mNumber--;  
            adapter.NotifyDataSetChanged();  
        }  
    }  
   
    class MyCheckListener : Java.Lang.Object, CompoundButton.IOnCheckedChangeListener  
    {  
        Photo photo;  
   
        public MyCheckListener( Photo item)  
        {  
            this.photo = item;  
        }  
   
        public void OnCheckedChanged(CompoundButton buttonView, bool isChecked)  
        {  
            photo.isChecked = isChecked;  
        }  
    }  
   
        public override int ItemCount  
        {  
            get { return mPhotoAlbum.Count; }  
        }  
   
        // Raise an event when the item-click takes place:  
        void OnClick(int position)  
        {  
            if (ItemClick != null)  
                ItemClick(this, position);  
        }  
    }  
   

Note: You can choose the mode( single click and hold & repeat functionality) according to the value of CheckBox. And in default, it is a single click.

Best Regards,

Jessie Zhang

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