[英]WinForms | C# | AutoComplete in the Middle of a Textbox?
我有一個文本框可以自動完成,如下所示:
txtName.AutoCompleteMode = AutoCompleteMode.Suggest;
txtName.AutoCompleteSource = AutoCompleteSource.CustomSource;
txtName.AutoCompleteCustomSource = namesCollection;
它有效,但僅在文本框的開頭。 我希望用戶在文本框中的任何位置輸入的任何單詞都可以使用自動填充功能。
using System;
using System.Collections.Generic;
using System.Drawing;
using System.Windows.Forms;
namespace TubeUploader
{
public class AutoCompleteTextBox : TextBox
{
private ListBox _listBox;
private bool _isAdded;
private String[] _values;
private String _formerValue = String.Empty;
public AutoCompleteTextBox()
{
InitializeComponent();
ResetListBox();
}
private void InitializeComponent()
{
_listBox = new ListBox();
KeyDown += this_KeyDown;
KeyUp += this_KeyUp;
}
private void ShowListBox()
{
if (!_isAdded)
{
Parent.Controls.Add(_listBox);
_listBox.Left = Left;
_listBox.Top = Top + Height;
_isAdded = true;
}
_listBox.Visible = true;
_listBox.BringToFront();
}
private void ResetListBox()
{
_listBox.Visible = false;
}
private void this_KeyUp(object sender, KeyEventArgs e)
{
UpdateListBox();
}
private void this_KeyDown(object sender, KeyEventArgs e)
{
switch (e.KeyCode)
{
case Keys.Tab:
{
if (_listBox.Visible)
{
InsertWord((String)_listBox.SelectedItem);
ResetListBox();
_formerValue = Text;
}
break;
}
case Keys.Down:
{
if ((_listBox.Visible) && (_listBox.SelectedIndex < _listBox.Items.Count - 1))
_listBox.SelectedIndex++;
break;
}
case Keys.Up:
{
if ((_listBox.Visible) && (_listBox.SelectedIndex > 0))
_listBox.SelectedIndex--;
break;
}
}
}
protected override bool IsInputKey(Keys keyData)
{
switch (keyData)
{
case Keys.Tab:
return true;
default:
return base.IsInputKey(keyData);
}
}
private void UpdateListBox()
{
if (Text == _formerValue) return;
_formerValue = Text;
String word = GetWord();
if (_values != null && word.Length > 0)
{
String[] matches = Array.FindAll(_values,
x => (x.StartsWith(word, StringComparison.OrdinalIgnoreCase) && !SelectedValues.Contains(x)));
if (matches.Length > 0)
{
ShowListBox();
_listBox.Items.Clear();
Array.ForEach(matches, x => _listBox.Items.Add(x));
_listBox.SelectedIndex = 0;
_listBox.Height = 0;
_listBox.Width = 0;
Focus();
using (Graphics graphics = _listBox.CreateGraphics())
{
for (int i = 0; i < _listBox.Items.Count; i++)
{
_listBox.Height += _listBox.GetItemHeight(i);
// it item width is larger than the current one
// set it to the new max item width
// GetItemRectangle does not work for me
// we add a little extra space by using '_'
int itemWidth = (int)graphics.MeasureString(((String)_listBox.Items[i]) + "_", _listBox.Font).Width;
_listBox.Width = (_listBox.Width < itemWidth) ? itemWidth : _listBox.Width;
}
}
}
else
{
ResetListBox();
}
}
else
{
ResetListBox();
}
}
private String GetWord()
{
String text = Text;
int pos = SelectionStart;
int posStart = text.LastIndexOf(' ', (pos < 1) ? 0 : pos - 1);
posStart = (posStart == -1) ? 0 : posStart + 1;
int posEnd = text.IndexOf(' ', pos);
posEnd = (posEnd == -1) ? text.Length : posEnd;
int length = ((posEnd - posStart) < 0) ? 0 : posEnd - posStart;
return text.Substring(posStart, length);
}
private void InsertWord(String newTag)
{
String text = Text;
int pos = SelectionStart;
int posStart = text.LastIndexOf(' ', (pos < 1) ? 0 : pos - 1);
posStart = (posStart == -1) ? 0 : posStart + 1;
int posEnd = text.IndexOf(' ', pos);
String firstPart = text.Substring(0, posStart) + newTag;
String updatedText = firstPart + ((posEnd == -1) ? "" : text.Substring(posEnd, text.Length - posEnd));
Text = updatedText;
SelectionStart = firstPart.Length;
}
public String[] Values
{
get
{
return _values;
}
set
{
_values = value;
}
}
public List<String> SelectedValues
{
get
{
String[] result = Text.Split(new[] { ' ' }, StringSplitOptions.RemoveEmptyEntries);
return new List<String>(result);
}
}
}
}
樣品用量
using System;
using System.Windows.Forms;
namespace AutoComplete
{
public partial class TestForm : Form
{
private readonly String[] _values = { "one", "two", "three", "tree", "four", "fivee" };
public TestForm()
{
InitializeComponent();
// AutoComplete is our special textbox control on the form
AutoComplete.Values = _values;
}
}
}
我對@PaRiMaL RaJ提出的解決方案進行了一些更改,因為當文本框位於不夠高的UserControl內時,列表框未顯示。 基本上,我沒有將列表框添加到文本框的父級,而是添加到了表單,並計算了表單中的絕對位置。
public class AutoCompleteTextBox : TextBox
{
private ListBox _listBox;
private bool _isAdded;
private String[] _values;
private String _formerValue = String.Empty;
public AutoCompleteTextBox()
{
InitializeComponent();
ResetListBox();
}
private void InitializeComponent()
{
_listBox = new ListBox();
this.KeyDown += this_KeyDown;
this.KeyUp += this_KeyUp;
}
private void ShowListBox()
{
if (!_isAdded)
{
Form parentForm = this.FindForm(); // new line added
parentForm.Controls.Add(_listBox); // adds it to the form
Point positionOnForm = parentForm.PointToClient(this.Parent.PointToScreen(this.Location)); // absolute position in the form
_listBox.Left = positionOnForm.X;
_listBox.Top = positionOnForm.Y + Height;
_isAdded = true;
}
_listBox.Visible = true;
_listBox.BringToFront();
}
private void ResetListBox()
{
_listBox.Visible = false;
}
private void this_KeyUp(object sender, KeyEventArgs e)
{
UpdateListBox();
}
private void this_KeyDown(object sender, KeyEventArgs e)
{
switch (e.KeyCode)
{
case Keys.Enter:
case Keys.Tab:
{
if (_listBox.Visible)
{
Text = _listBox.SelectedItem.ToString();
ResetListBox();
_formerValue = Text;
this.Select(this.Text.Length, 0);
e.Handled = true;
}
break;
}
case Keys.Down:
{
if ((_listBox.Visible) && (_listBox.SelectedIndex < _listBox.Items.Count - 1))
_listBox.SelectedIndex++;
e.Handled = true;
break;
}
case Keys.Up:
{
if ((_listBox.Visible) && (_listBox.SelectedIndex > 0))
_listBox.SelectedIndex--;
e.Handled = true;
break;
}
}
}
protected override bool IsInputKey(Keys keyData)
{
switch (keyData)
{
case Keys.Tab:
if (_listBox.Visible)
return true;
else
return false;
default:
return base.IsInputKey(keyData);
}
}
private void UpdateListBox()
{
if (Text == _formerValue)
return;
_formerValue = this.Text;
string word = this.Text;
if (_values != null && word.Length > 0)
{
string[] matches = Array.FindAll(_values,
x => (x.ToLower().Contains(word.ToLower())));
if (matches.Length > 0)
{
ShowListBox();
_listBox.BeginUpdate();
_listBox.Items.Clear();
Array.ForEach(matches, x => _listBox.Items.Add(x));
_listBox.SelectedIndex = 0;
_listBox.Height = 0;
_listBox.Width = 0;
Focus();
using (Graphics graphics = _listBox.CreateGraphics())
{
for (int i = 0; i < _listBox.Items.Count; i++)
{
if (i < 20)
_listBox.Height += _listBox.GetItemHeight(i);
// it item width is larger than the current one
// set it to the new max item width
// GetItemRectangle does not work for me
// we add a little extra space by using '_'
int itemWidth = (int)graphics.MeasureString(((string)_listBox.Items[i]) + "_", _listBox.Font).Width;
_listBox.Width = (_listBox.Width < itemWidth) ? itemWidth : this.Width; ;
}
}
_listBox.EndUpdate();
}
else
{
ResetListBox();
}
}
else
{
ResetListBox();
}
}
public String[] Values
{
get
{
return _values;
}
set
{
_values = value;
}
}
public List<String> SelectedValues
{
get
{
String[] result = Text.Split(new[] { ' ' }, StringSplitOptions.RemoveEmptyEntries);
return new List<String>(result);
}
}
}
其他解決方案在多行環境中無法滿足我的需求,因此我在@Francisco Goldenstein的答案中添加了此功能。 我需要的是在文本框中以及任何位置/任何行上自動完成所有“單詞”。 經過最少的測試,該類在多行TextBox中似乎對我來說足夠好。 希望它可以幫助某人。
主要更改是在UpdateListBox()
和this_KeyDown()
,以處理“當前”單詞,即插入符號前的單詞,而不是整個文本框內容。
更改UpdateListBox()
中separators
的定義以適合您的需求。
using System;
using System.Drawing;
using System.Windows.Forms;
class MultiLineAutoCompleteTextBox : TextBox
{
private ListBox _listBox;
private bool _isAdded;
private String[] _values;
private String _formerValue = String.Empty;
private int _prevBreak;
private int _nextBreak;
private int _wordLen;
public MultiLineAutoCompleteTextBox()
{
InitializeComponent();
ResetListBox();
}
private void InitializeComponent()
{
_listBox = new ListBox();
KeyDown += this_KeyDown;
KeyUp += this_KeyUp;
}
private void ShowListBox()
{
if (!_isAdded)
{
Form parentForm = FindForm();
if (parentForm == null) return;
parentForm.Controls.Add(_listBox);
Point positionOnForm = parentForm.PointToClient(Parent.PointToScreen(Location));
_listBox.Left = positionOnForm.X;
_listBox.Top = positionOnForm.Y + Height;
_isAdded = true;
}
_listBox.Visible = true;
_listBox.BringToFront();
}
private void ResetListBox()
{
_listBox.Visible = false;
}
private void this_KeyUp(object sender, KeyEventArgs e)
{
UpdateListBox();
}
private void this_KeyDown(object sender, KeyEventArgs e)
{
switch (e.KeyCode)
{
case Keys.Enter:
case Keys.Tab:
case Keys.Space:
{
if (_listBox.Visible)
{
Text = Text.Remove(_prevBreak == 0 ? 0 : _prevBreak + 1, _prevBreak == 0 ? _wordLen + 1 : _wordLen);
Text = Text.Insert(_prevBreak == 0 ? 0 : _prevBreak + 1, _listBox.SelectedItem.ToString());
ResetListBox();
_formerValue = Text;
Select(Text.Length, 0);
e.Handled = true;
}
break;
}
case Keys.Down:
{
if ((_listBox.Visible) && (_listBox.SelectedIndex < _listBox.Items.Count - 1))
_listBox.SelectedIndex++;
e.Handled = true;
break;
}
case Keys.Up:
{
if ((_listBox.Visible) && (_listBox.SelectedIndex > 0))
_listBox.SelectedIndex--;
e.Handled = true;
break;
}
}
}
protected override bool IsInputKey(Keys keyData)
{
switch (keyData)
{
case Keys.Tab:
if (_listBox.Visible)
return true;
else
return false;
default:
return base.IsInputKey(keyData);
}
}
private void UpdateListBox()
{
if (Text == _formerValue) return;
if (Text.Length == 0)
{
_listBox.Visible = false;
return;
}
_formerValue = Text;
var separators = new[] { '|', '[', ']', '\r', '\n', ' ', '\t' };
_prevBreak = Text.LastIndexOfAny(separators, CaretIndex > 0 ? CaretIndex - 1 : 0);
if (_prevBreak < 1) _prevBreak = 0;
_nextBreak = Text.IndexOfAny(separators, _prevBreak + 1);
if (_nextBreak == -1) _nextBreak = CaretIndex;
_wordLen = _nextBreak - _prevBreak - 1;
if (_wordLen < 1) return;
string word = Text.Substring(_prevBreak + 1, _wordLen);
if (_values != null && word.Length > 0)
{
string[] matches = Array.FindAll(_values,
x => (x.ToLower().Contains(word.ToLower())));
if (matches.Length > 0)
{
ShowListBox();
_listBox.BeginUpdate();
_listBox.Items.Clear();
Array.ForEach(matches, x => _listBox.Items.Add(x));
_listBox.SelectedIndex = 0;
_listBox.Height = 0;
_listBox.Width = 0;
Focus();
using (Graphics graphics = _listBox.CreateGraphics())
{
for (int i = 0; i < _listBox.Items.Count; i++)
{
if (i < 20)
_listBox.Height += _listBox.GetItemHeight(i);
// it item width is larger than the current one
// set it to the new max item width
// GetItemRectangle does not work for me
// we add a little extra space by using '_'
int itemWidth = (int)graphics.MeasureString(((string)_listBox.Items[i]) + "_", _listBox.Font).Width;
_listBox.Width = (_listBox.Width < itemWidth) ? itemWidth : Width; ;
}
}
_listBox.EndUpdate();
}
else
{
ResetListBox();
}
}
else
{
ResetListBox();
}
}
public int CaretIndex => SelectionStart;
public String[] Values
{
get
{
return _values;
}
set
{
_values = value;
}
}
}
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