WinForm 自动完成控件实例代码简析

2020-01-24 03:36:38

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在Web的应用方面有js的插件实现自动完成（或叫智能提示）功能，但在WinForm窗体应用方面就没那么好了。

TextBox控件本身是提供了一个自动提示功能，只要用上这三个属性：
AutoCompleteCustomSource：AutoCompleteSource 属性设置为CustomSource 时要使用的 StringCollection。
AutoCompleteMode：指示文本框的文本完成行为。
AutoCompleteSource：自动完成源，可以是 AutoCompleteSource 的枚举值之一。

就行了，一个简单的示例如下

复制代码代码如下:

 
textBox1.AutoCompleteCustomSource .AddRange(new string[] { "java","javascript","js","c#","c","c++" }); 
textBox1.AutoCompleteMode = AutoCompleteMode.SuggestAppend; 
textBox1.AutoCompleteSource = AutoCompleteSource.CustomSource; 

可是这种方式的不支持我们中文的简拼自动完成（如在文本框里输入"gz"就会出现"广州"）。只好自己写一个支持简拼自动完成的控件了。
这是效果图

控件不太复杂，一个TextBox和一个ListBox。代码方面，用DataTable作数据源，每次在TextBox的值时，通过DataTable的Select方法，配上合适的表达式(如：{0} like '{1}%' and IsNull([{2}], ' ') <> ' ')来筛选出合适的备选文本内容，以下则是控件的代码：

复制代码代码如下:

 
private TextBox _tb; 
private ListBox _lb; 
private DataTable _dt_datasource; 
private bool _text_lock; 
private string _general_text;//原始输入文本框的值 
private bool _lb_kd_first_top;//listbox是否第一次到达顶部 
private int _itemCount; 

复制代码代码如下:

 
/// <summary> 
/// TextBox的Text属性，增加了_text_lock操作，放置触发TextChanged事件 
/// </summary> 
private string TextBoxText 
{ 
get { return _tb.Text; } 
set 
{ 
_text_lock = true; 
_tb.Text = value; 
_text_lock = false; 
} 
} 
/// <summary> 
/// 显示在ListBox的字段名 
/// </summary> 
public string ValueName { get; set; } 
/// <summary> 
/// 用于匹配的字段名 
/// </summary> 
public string CodeName { get; set; } 
/// <summary> 
/// 显示提示项的数量 
/// </summary> 
public int ItemCount 
{ 
get 
{ return _itemCount; } 
set 
{ 
if (value <= 0) 
_itemCount = 1; 
else 
_itemCount = value; 
} 
} 
public DataTable DataSource 
{ 
get { return _dt_datasource; } 
set { _dt_datasource = value; } 
} 

复制代码代码如下:

 
 public AutoComplete() 
 { 
 InitialControls(); 
 } 

复制代码代码如下:

 
void AutoComplete_Load(object sender, EventArgs e) 
{ 
_tb.Width = this.Width; 
_lb.Width = _tb.Width; 
this.Height = _tb.Height-1; 
} 
void AutoComplete_LostFocus(object sender, EventArgs e) 
{ 
_lb.Visible = false; 
this.Height = _tb.Height-1; 
} 

复制代码代码如下:

 
//列表框按键事件 
void _lb_KeyDown(object sender, KeyEventArgs e) 
{ 
if (_lb.Items.Count == 0 || !_lb.Visible) return; 
if (!_lb_kd_first_top && ((e.KeyCode == Keys.Up && _lb.SelectedIndex == 0) || (e.KeyCode == Keys.Down && _lb.SelectedIndex == _lb.Items.Count))) 
{ 
_lb.SelectedIndex = -1; 
TextBoxText = _general_text; 
} 
else 
{ 
TextBoxText = ((DataRowView)_lb.SelectedItem)[ValueName].ToString(); 
_lb_kd_first_top = _lb.SelectedIndex != 0; 
} 
if (e.KeyCode == Keys.Enter && _lb.SelectedIndex != -1) 
{ 
_lb.Visible = false; 
this.Height = _tb.Height; 
_tb.Focus(); 
} 
} 
//列表鼠标单击事件 
void _lb_Click(object sender, EventArgs e) 
{ 
if (_lb.SelectedIndex != -1) 
{ 
TextBoxText = ((DataRowView)_lb.SelectedItem)[ValueName].ToString(); 
} 
_lb.Visible = false; 
_tb.Focus(); 
this.Height = _tb.Height; 
} 

复制代码代码如下:

 
//文本框按键事件 
void _tb_KeyDown(object sender, KeyEventArgs e) 
{ 
if (_lb.Items.Count == 0||!_lb.Visible) return; 
bool _is_set = false; 
if (e.KeyCode == Keys.Up) 
{ 
if (_lb.SelectedIndex <= 0) 
{ 
_lb.SelectedIndex = -1; 
TextBoxText = _general_text; 
} 
else 
{ 
_lb.SelectedIndex--; 
_is_set = true; 
} 
} 
else if (e.KeyCode == Keys.Down) 
{ 
if (_lb.SelectedIndex == _lb.Items.Count - 1) 
{ 
_lb.SelectedIndex = 0; 
_lb.SelectedIndex = -1; 
TextBoxText = _general_text; 
} 
else 
{ 
_lb.SelectedIndex++; 
_is_set = true; 
} 
} 
else if (e.KeyCode == Keys.Enter) 
{ 
_lb.Visible = false; 
this.Height = _tb.Height; 
_is_set = _lb.SelectedIndex != -1; 
} 
_lb_kd_first_top = _lb.SelectedIndex != 0; 
if (_is_set) 
{ 
_text_lock = true; 
_tb.Text = ((DataRowView)_lb.SelectedItem)[ValueName].ToString(); 
_tb.SelectionStart = _tb.Text.Length + 10; 
_tb.SelectionLength = 0; 
_text_lock = false; 
} 
} 
//文本框文本变更事件 
void _tb_TextChanged(object sender, EventArgs e) 
{ 
if (_text_lock) return; 
_general_text = _tb.Text; 
_lb.Visible = true; 
_lb.Height = _lb.ItemHeight * (_itemCount+1); 
this.BringToFront(); 
_lb.BringToFront(); 
this.Height = _tb.Height + _lb.Height; 
DataTable temp_table = _dt_datasource.Clone(); 
string filtStr = FormatStr(_tb.Text); 
DataRow [] rows = _dt_datasource.Select(string.Format(GetFilterStr(),CodeName,filtStr,_lb.DisplayMember)); 
for (int i = 0; i < rows.Length&&i<_itemCount; i++) 
{ 
temp_table.Rows.Add(rows[i].ItemArray); 
} 
_lb.DataSource = temp_table; 
if (_lb.Items.Count > 0) _lb.SelectedItem = _lb.Items[0]; 
} 

复制代码代码如下:

 
/// <summary> 
/// 初始化控件 
/// </summary> 
private void InitialControls() 
{ 
_lb_kd_first_top = true; 
_tb = new TextBox(); 
_tb.Location = new Point(0, 0); 
_tb.Margin = new System.Windows.Forms.Padding(0); 
_tb.Width = this.Width; 
_tb.TextChanged += new EventHandler(_tb_TextChanged); 
_tb.KeyUp += new KeyEventHandler(_tb_KeyDown); 
_lb = new ListBox(); 
_lb.Visible = false; 
_lb.Width = _tb.Width; 
_lb.Margin = new System.Windows.Forms.Padding(0); 
_lb.DisplayMember = ValueName; 
_lb.SelectionMode = SelectionMode.One; 
_lb.Location = new Point(0, _tb.Height); 
_lb.KeyUp += new KeyEventHandler(_lb_KeyDown); 
_lb.Click += new EventHandler(_lb_Click); 
this.Controls.Add(_tb); 
this.Controls.Add(_lb); 
this.Height = _tb.Height - 1; 
this.LostFocus += new EventHandler(AutoComplete_LostFocus); 
this.Leave += new EventHandler(AutoComplete_LostFocus); 
this.Load += new EventHandler(AutoComplete_Load); 
} 
/// <summary> 
/// 获取过滤格式字符串 
/// </summary> 
/// <returns></returns> 
private string GetFilterStr() 
{ 
//未过滤注入的字符 ' ] %任意 *任意 
string filter = " {0} like '{1}%' and IsNull([{2}], ' ') <> ' ' "; 
if (_dt_datasource.Rows[0][CodeName].ToString().LastIndexOf(';') > -1) 
filter = " {0} like '%;{1}%' and IsNull([{2}],' ') <> ' ' "; 
return filter; 
} 
/// <summary> 
/// 过滤字符串中一些可能造成出错的字符 
/// </summary> 
/// <param name="str"></param> 
/// <returns></returns> 
private string FormatStr(string str) 
{ 
if (string.IsNullOrEmpty(str)) return string.Empty; 
str = str.Replace("[", "[[]").Replace("%", "[%]").Replace("*", "[*]").Replace("'", "''"); 
if (CodeName == "code") str = str.Replace(" ", ""); 
return str; 
} 

下面是使用控件的例子

复制代码代码如下:

 
class Common 
{ 
/// <summary> 
/// 生成测试数据源 
/// </summary> 
public static DataTable CreateTestDataSoucre 
{ 
get 
{ 
List<KeyValuePair<string, string>> source = new List<KeyValuePair<string, string>>() 
{ 
new KeyValuePair<string,string>("张三",";zs;张三;"), 
new KeyValuePair<string,string>("李四",";li;李四;"), 
new KeyValuePair<string,string>("王五",";ww;王五;"), 
new KeyValuePair<string,string>("赵六",";zl;赵六;"), 
new KeyValuePair<string,string>("洗刷",";cs;csharp;c#;洗刷;"), 
new KeyValuePair<string,string>("爪哇",";java;爪哇;"), 
new KeyValuePair<string,string>("java",";java;"), 
new KeyValuePair<string,string>("c#",";c#;cs;csharp;"), 
new KeyValuePair<string,string>("javascript",";javascript;js;") 
}; 
DataTable table = new DataTable(); 
table.Columns.Add("id"); 
table.Columns.Add("name"); 
table.Columns.Add("code"); 
for (int i = 0; i < source.Count; i++) 
{ 
DataRow row = table.Rows.Add(); 
row["id"] = i; 
row["name"] = source[i].Key; 
row["code"] = source[i].Value; 
} 
return table; 
} 
} 
} 
//............. 
AutoComplete ac=new AutoComplete(); 
ac.ValueName = "name"; 
ac.CodeName = "code"; 
ac.DataSource= Common.CreateTestDataSoucre; 
ac.ItemCount= 5; 