在MultiAutoCompleteTextView中设置每个令牌的样式

Question

我有一个MultiAutoCompleteTextView，而且我正在传递国家/地区名称，这样就行了，用户可以选择不同的国家/地区。

但我想为每个文本添加样式，例如以下

我已经研究了很多解决方案，例如

https://github.com/splitwise/TokenAutoComplete

https://github.com/shanempope/TokenAutoCompleteXamarinBinding（C＃Binding）

但我的要求很简单，我只想为MultiAutoCompleteTextView中的每个文本设置样式 - 是否可以不使用外部库？

Answer 1

我已经完成了一些事情，你可以尝试一下：

 public class MainActivity : AppCompatActivity, AdapterView.IOnItemClickListener
    {
        SpannableStringBuilder sb = new SpannableStringBuilder();
        string[] words = new string[] {
                "word1", "word2", "word3", "word4", "word5"};
        MultiAutoCompleteTextView macTv;
        public void OnItemClick(AdapterView parent, View view, int position, long id)
        {
            sb.Append(words[position] + " ");

            sb.SetSpan(new RoundedBackgroundSpan(this), sb.Length() - (words[position].Length + 1), sb.Length() - 1, SpanTypes.ExclusiveExclusive);
            macTv.SetText( sb,null);

            macTv.SetSelection(sb.Length());
        }

        protected override void OnCreate(Bundle savedInstanceState)
        {
            base.OnCreate(savedInstanceState);

            // Set our view from the "main" layout resource
            SetContentView(Resource.Layout.activity_main);

            macTv = (MultiAutoCompleteTextView)this.FindViewById(Resource.Id.mac_tv);
            ArrayAdapter<string> aaStr = new ArrayAdapter<string>(this, Android.Resource.Layout.SimpleDropDownItem1Line, words);
            macTv.Adapter=aaStr;
            macTv.OnItemClickListener = this;
            macTv.SetTokenizer(new myTokenizer());
        }

        public class myTokenizer : Java.Lang.Object, ITokenizer
        {
            public int FindTokenEnd(ICharSequence text, int cursor)
            {
                int i = cursor;
                int len = text.Length();

                while (i < len)
                {
                    if (text.CharAt(i) == ' ')
                    {
                        return i;
                    }
                    else
                    {
                        i++;
                    }
                }

                return len;
            }

            public int FindTokenStart(ICharSequence text, int cursor)
            {
                int i = cursor;

                while (i > 0 && text.CharAt(i - 1) != ' ')
                {
                    i--;
                }
                while (i < cursor && text.CharAt(i) == ' ')
                {
                    i++;
                }

                return i;  
            }

            public ICharSequence TerminateTokenFormatted(ICharSequence text)
            {
                int i = text.Length();

                while (i > 0 && text.CharAt(i - 1) == ' ')
                {
                    i--;
                }

                if (i > 0 && text.CharAt(i - 1) == ' ')
                {
                    return text;
                }
                else
                {
                    if (text is ISpanned) {

                        ISpannable sp = new SpannableString(text + " ");

                        TextUtils.CopySpansFrom((ISpanned)text, 0, text.Length(), Java.Lang.Class.FromType(typeof(object)), sp, 0);
                        return sp;
                    } else {        
                        return new SpannableString(text + " ");
                    }
                }


            }
        }
        public class RoundedBackgroundSpan : ReplacementSpan
        {

            private int CORNER_RADIUS = 10;
            private Color backgroundColor = Color.White;
            private Color textColor = Color.White;
            public RoundedBackgroundSpan(Context context): base()
            {

                backgroundColor =Color.Red;
            }



            public override void Draw(Canvas canvas, ICharSequence text, int start, int end, float x, int top, int y, int bottom, Paint paint)
            {
                RectF rect = new RectF(x, top, x + measureText(paint, text, start, end), bottom);
                paint.Color= backgroundColor;
                canvas.DrawRoundRect(rect, CORNER_RADIUS, CORNER_RADIUS, paint);
                paint.Color = textColor;
                canvas.DrawText(text, start, end, x, y, paint);
            }


            public override int GetSize(Paint paint, ICharSequence text, int start, int end, Paint.FontMetricsInt fm)
            {
                return Java.Lang.Math.Round(paint.MeasureText(text, start, end));
            }

            private float measureText(Paint paint, ICharSequence text, int start, int end)
            {
            return paint.MeasureText(text, start, end);
            }
    }
}

这是布局：

  <MultiAutoCompleteTextView
    android:id="@+id/mac_tv"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:completionThreshold="1"
        />

</RelativeLayout>