Rename NetchLib to SearchComboBox

SearchComboBox/SearchComboBox.cs

@@ -0,0 +1,179 @@
+using System.Linq;
+
+namespace System.Windows.Forms
+{
+    [System.ComponentModel.DesignerCategory(@"Code")]
+    public class SearchComboBox : ComboBox
+    {
+        public SearchComboBox()
+        {
+            AutoCompleteMode = AutoCompleteMode.Suggest;
+        }
+
+
+        private string prevKeyword;
+
+        private string Keyword
+        {
+            get => _keyword;
+            set
+            {
+                prevKeyword = _keyword;
+                if (value == null)
+                {
+                    _keyword = null;
+                    return;
+                }
+
+                if (_keyword == value)
+                {
+                    return;
+                }
+
+                _keyword = value;
+                ReevaluateCompletionList();
+            }
+        }
+
+        protected override void OnTextChanged(EventArgs e)
+        {
+            try
+            {
+                if (string.IsNullOrEmpty(Text))
+                {
+                    if (!IsOriginalItems)
+                        ResetCompletionList();
+                    Keyword = null;
+                }
+                else
+                {
+                    if (AutoFillTag.All(o => o.ToString() != Text))
+                    {
+                        Keyword = Text;
+                    }
+                }
+            }
+            finally
+            {
+                base.OnTextChanged(e);
+            }
+        }
+
+
+        private object[] AutoFillTag
+        {
+            get
+            {
+                if (Tag == null)
+                {
+                    Tag = Items.Cast<object>().ToArray();
+                }
+
+                return (object[]) Tag;
+            }
+        }
+
+        private bool IsOriginalItems => Items.Count == AutoFillTag.Length;
+
+        public void ResetCompletionList()
+        {
+            Keyword = null;
+            try
+            {
+                SuspendLayout();
+
+                if (IsOriginalItems)
+                    return;
+
+                Items.Clear();
+                Items.AddRange(AutoFillTag);
+            }
+            finally
+            {
+                ResumeLayout(true);
+            }
+        }
+
+        private static int findFirstDifIndex(string s1, string s2)
+        {
+            for (var i = 0; i < Math.Min(s1.Length, s2.Length); i++)
+                if (s1[i] != s2[i])
+                    return i;
+
+            return -1;
+        }
+
+        private object[] _newList;
+        private string _keyword;
+
+        private void ReevaluateCompletionList()
+        {
+            SuspendLayout();
+            var keyword = Keyword.ToLowerInvariant().Trim();
+
+            var selectionStart = SelectionStart;
+            if (selectionStart == Text.Length)
+            {
+                selectionStart = -1;
+            }
+            else
+            {
+                selectionStart = findFirstDifIndex(prevKeyword, Keyword);
+            }
+
+            try
+            {
+                var originalList = AutoFillTag;
+                if (originalList == null)
+                {
+                    Tag = originalList = Items.Cast<object>().ToArray();
+                }
+
+                if (string.IsNullOrEmpty(Keyword))
+                {
+                    ResetCompletionList();
+                    return;
+                }
+                else
+                {
+                    _newList = originalList.Where(x => x.ToString().ToLowerInvariant().Contains(keyword)).ToArray();
+                }
+
+                if (_newList.Any())
+                {
+                    Items.Clear();
+                    Items.AddRange(_newList.ToArray());
+
+                    if (!DroppedDown)
+                    {
+                        DroppedDown = true;
+                    }
+                    else
+                    {
+                        // TODO 预期下拉框高度变长则重新打开下拉框
+                    }
+
+                    Cursor.Current = Cursors.Default;
+                }
+                else
+                {
+                    DroppedDown = false;
+                    Items.Clear();
+                }
+
+                if (selectionStart == -1)
+                {
+                    Select(Text.Length, 0);
+                }
+                else
+                {
+                    Select(selectionStart + 1, 0);
+                }
+            }
+            finally
+            {
+                ResumeLayout(true);
+            }
+        }
+    }
+}