MultiAutoCompleteTextView android restrict user from selecting same value multiple times

MultiAutoCompleteTextView android how to restrict user from selecting same value multiple times?

You could check the values which selected in ItemClick event.

I make a code sample for you.

layout2.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<MultiAutoCompleteTextView
android:id="@+id/multiAutoCompleteTextView1"
                         android:layout_width="match_parent"
                         android:layout_height="wrap_content"/>
</LinearLayout>

MainActivity.cs

 var multiAutoCompleteTextView1 = FindViewById<MultiAutoCompleteTextView>(Resource.Id.multiAutoCompleteTextView1);

        string[] arraydata = { "apple1", "apple2", "shanghai1", "shanghai2" };

        ArrayAdapter<string> adapter = new ArrayAdapter<string>(this, Android.Resource.Layout.SimpleListItem1, arraydata);
        multiAutoCompleteTextView1.Adapter = adapter;
        multiAutoCompleteTextView1.SetTokenizer(new MultiAutoCompleteTextView.CommaTokenizer());

        string PreviousText = string.Empty;

        multiAutoCompleteTextView1.ItemClick += (s, e) =>
        {
            var currentText = multiAutoCompleteTextView1.Text;
            var currentList = currentText.Replace(" ","").Split(',');
            var length = currentList.Length;
            if (length > 2)
            {
                for (int i = 0; i < length - 1; i++)
                {
                    if (i < length - 2)
                    {
                        if (currentList[i] == currentList[length - 2])
                        {
                            multiAutoCompleteTextView1.Text = PreviousText;
                            //do the something when you select the same value
                        }
                    }

                }

            }

            PreviousText = multiAutoCompleteTextView1.Text;
        };

In the sample code, i reset the value of MultiAutoCompleteTextView when select the same value.