C#自动完成
我正在尝试向文本框添加自动完成功能，结果来自数据库。它们以 [001]最后，第一个中间 当前必须键入[001]。。。以获取要显示的条目所以问题是，即使我先键入名字，我也希望它完成。所以如果一个条目是 [001]史密斯，约翰·D 如果我开始输入John，那么这个条目应该显示在自动完成的结果中 目前代码看起来像C#自动完成,c#,winforms,autocomplete,C#,Winforms,Autocomplete,我正在尝试向文本框添加自动完成功能，结果来自数据库。它们以 [001]最后，第一个中间 当前必须键入[001]。。。以获取要显示的条目所以问题是，即使我先键入名字，我也希望它完成。所以如果一个条目是 [001]史密斯，约翰·D 如果我开始输入John，那么这个条目应该显示在自动完成的结果中 目前代码看起来像 AutoCompleteStringCollection acsc = new AutoCompleteStringCollection(); txtBox1.AutoCompleteCus
AutoCompleteStringCollection acsc = new AutoCompleteStringCollection();
txtBox1.AutoCompleteCustomSource = acsc;
txtBox1.AutoCompleteMode = AutoCompleteMode.Suggest;
txtBox1.AutoCompleteSource = AutoCompleteSource.CustomSource;
....
if (results.Rows.Count > 0)
for (int i = 0; i < results.Rows.Count && i < 10; i++)
{
row = results.Rows[i];
acsc.Add(row["Details"].ToString());
}
}
{0}是搜索字符串的占位符。如果正在运行该查询（用输入的字符串替换
{0}SELECT Name from view_customers where Details LIKE '%{0}%'
LIKE%此外，您似乎返回了
名称详细信息详细信息列中，您将无法得到想要的信息。如果您决定使用基于用户输入的查询，请确保使用SqlParameters来避免SQL注入攻击
SqlCommand sqlCommand = new SqlCommand();
sqlCommand.CommandText = "SELECT Name from view_customers where Details LIKE '%" + @SearchParam + "%'";
sqlCommand.Parameters.AddWithValue("@SearchParam", searchParam);
现有的自动完成功能仅支持按前缀搜索。似乎没有任何像样的方法来推翻这种行为
有些人通过覆盖OnTextChanged
事件实现了自己的自动完成功能。那可能是你最好的选择
例如，您可以在文本框
的正下方添加一个列表框
，并将其默认可见性设置为false。然后，您可以使用文本框的OnTextChanged
事件和列表框的SelectedIndexChanged
事件来显示和选择项目
这似乎是一个基本的例子：
public Form1()
{
InitializeComponent();
acsc = new AutoCompleteStringCollection();
textBox1.AutoCompleteCustomSource = acsc;
textBox1.AutoCompleteMode = AutoCompleteMode.None;
textBox1.AutoCompleteSource = AutoCompleteSource.CustomSource;
}
private void button1_Click(object sender, EventArgs e)
{
acsc.Add("[001] some kind of item");
acsc.Add("[002] some other item");
acsc.Add("[003] an orange");
acsc.Add("[004] i like pickles");
}
void textBox1_TextChanged(object sender, System.EventArgs e)
{
listBox1.Items.Clear();
if (textBox1.Text.Length == 0)
{
hideResults();
return;
}
foreach (String s in textBox1.AutoCompleteCustomSource)
{
if (s.Contains(textBox1.Text))
{
Console.WriteLine("Found text in: " + s);
listBox1.Items.Add(s);
listBox1.Visible = true;
}
}
}
void listBox1_SelectedIndexChanged(object sender, System.EventArgs e)
{
textBox1.Text = listBox1.Items[listBox1.SelectedIndex].ToString();
hideResults();
}
void listBox1_LostFocus(object sender, System.EventArgs e)
{
hideResults();
}
void hideResults()
{
listBox1.Visible = false;
}
不用花太多功夫，您还可以做很多事情：将文本附加到文本框中，捕获额外的键盘命令，等等。下面是一个继承组合框
控件类的实现，而不是用新控件替换整个组合框。当您在文本框中键入时，它会显示自己的下拉列表，但单击以显示下拉列表的处理方式与以前相同（即，不使用此代码）。因此，您可以获得适当的本机控制和外观
请使用它，修改它和编辑答案，如果你想改善它
class ComboListMatcher : ComboBox, IMessageFilter
{
private Control ComboParentForm; // Or use type "Form"
private ListBox listBoxChild;
private int IgnoreTextChange;
private bool MsgFilterActive = false;
public ComboListMatcher()
{
// Set up all the events we need to handle
TextChanged += ComboListMatcher_TextChanged;
SelectionChangeCommitted += ComboListMatcher_SelectionChangeCommitted;
LostFocus += ComboListMatcher_LostFocus;
MouseDown += ComboListMatcher_MouseDown;
HandleDestroyed += ComboListMatcher_HandleDestroyed;
}
void ComboListMatcher_HandleDestroyed(object sender, EventArgs e)
{
if (MsgFilterActive)
Application.RemoveMessageFilter(this);
}
~ComboListMatcher()
{
}
private void ComboListMatcher_MouseDown(object sender, MouseEventArgs e)
{
HideTheList();
}
void ComboListMatcher_LostFocus(object sender, EventArgs e)
{
if (listBoxChild != null && !listBoxChild.Focused)
HideTheList();
}
void ComboListMatcher_SelectionChangeCommitted(object sender, EventArgs e)
{
IgnoreTextChange++;
}
void InitListControl()
{
if (listBoxChild == null)
{
// Find parent - or keep going up until you find the parent form
ComboParentForm = this.Parent;
if (ComboParentForm != null)
{
// Setup a messaage filter so we can listen to the keyboard
if (!MsgFilterActive)
{
Application.AddMessageFilter(this);
MsgFilterActive = true;
}
listBoxChild = listBoxChild = new ListBox();
listBoxChild.Visible = false;
listBoxChild.Click += listBox1_Click;
ComboParentForm.Controls.Add(listBoxChild);
ComboParentForm.Controls.SetChildIndex(listBoxChild, 0); // Put it at the front
}
}
}
void ComboListMatcher_TextChanged(object sender, EventArgs e)
{
if (IgnoreTextChange > 0)
{
IgnoreTextChange = 0;
return;
}
InitListControl();
if (listBoxChild == null)
return;
string SearchText = this.Text;
listBoxChild.Items.Clear();
// Don't show the list when nothing has been typed
if (!string.IsNullOrEmpty(SearchText))
{
foreach (string Item in this.Items)
{
if (Item != null && Item.Contains(SearchText, StringComparison.CurrentCultureIgnoreCase))
listBoxChild.Items.Add(Item);
}
}
if (listBoxChild.Items.Count > 0)
{
Point PutItHere = new Point(this.Left, this.Bottom);
Control TheControlToMove = this;
PutItHere = this.Parent.PointToScreen(PutItHere);
TheControlToMove = listBoxChild;
PutItHere = ComboParentForm.PointToClient(PutItHere);
TheControlToMove.Show();
TheControlToMove.Left = PutItHere.X;
TheControlToMove.Top = PutItHere.Y;
TheControlToMove.Width = this.Width;
int TotalItemHeight = listBoxChild.ItemHeight * (listBoxChild.Items.Count + 1);
TheControlToMove.Height = Math.Min(ComboParentForm.ClientSize.Height - TheControlToMove.Top, TotalItemHeight);
}
else
HideTheList();
}
/// <summary>
/// Copy the selection from the list-box into the combo box
/// </summary>
private void CopySelection()
{
if (listBoxChild.SelectedItem != null)
{
this.SelectedItem = listBoxChild.SelectedItem;
HideTheList();
this.SelectAll();
}
}
private void listBox1_Click(object sender, EventArgs e)
{
var ThisList = sender as ListBox;
if (ThisList != null)
{
// Copy selection to the combo box
CopySelection();
}
}
private void HideTheList()
{
if (listBoxChild != null)
listBoxChild.Hide();
}
public bool PreFilterMessage(ref Message m)
{
if (m.Msg == 0x201) // Mouse click: WM_LBUTTONDOWN
{
var Pos = new Point((int)(m.LParam.ToInt32() & 0xFFFF), (int)(m.LParam.ToInt32() >> 16));
var Ctrl = Control.FromHandle(m.HWnd);
if (Ctrl != null)
{
// Convert the point into our parent control's coordinates ...
Pos = ComboParentForm.PointToClient(Ctrl.PointToScreen(Pos));
// ... because we need to hide the list if user clicks on something other than the list-box
if (ComboParentForm != null)
{
if (listBoxChild != null &&
(Pos.X < listBoxChild.Left || Pos.X > listBoxChild.Right || Pos.Y < listBoxChild.Top || Pos.Y > listBoxChild.Bottom))
{
this.HideTheList();
}
}
}
}
else if (m.Msg == 0x100) // WM_KEYDOWN
{
if (listBoxChild != null && listBoxChild.Visible)
{
switch (m.WParam.ToInt32())
{
case 0x1B: // Escape key
this.HideTheList();
return true;
case 0x26: // up key
case 0x28: // right key
// Change selection
int NewIx = listBoxChild.SelectedIndex + ((m.WParam.ToInt32() == 0x26) ? -1 : 1);
// Keep the index valid!
if (NewIx >= 0 && NewIx < listBoxChild.Items.Count)
listBoxChild.SelectedIndex = NewIx;
return true;
case 0x0D: // return (use the currently selected item)
CopySelection();
return true;
}
}
}
return false;
}
}
类ComboListMatcher:ComboBox，IMessageFilter
{
私有控件ComboParentForm；//或使用类型“Form”
私有ListBox listBoxChild；
私有int IgnoreTextChange；
private bool MsgFilterActive=false；
公共ComboListMatcher（）
{
//设置我们需要处理的所有事件
TextChanged+=ComboListMatcher\u TextChanged；
SelectionChangeCommitted+=ComboListMatcher\u SelectionChangeCommitted；
LostFocus+=ComboListMatcher\u LostFocus；
MouseDown+=ComboListMatcher\u MouseDown；
HandleDestroyed+=ComboListMatcher\u HandleDestroyed；
}
void ComboListMatcher_HandleDestroyed（对象发送方，事件参数e）
{
if（MsgFilterActive）
Application.RemoveMessageFilter（此）；
}
~ComboListMatcher（）
{
}
私有void ComboListMatcher_MouseDown（对象发送方，MouseEventArgs e）
{
隐藏列表（）；
}
void ComboListMatcher\u LostFocus（对象发送方，事件参数e）
{
if（listBoxChild！=null&&！listBoxChild.Focused）
隐藏列表（）；
}
void ComboListMatcher\u SelectionChangeCommitted（对象发送方，事件参数e）
{
IgnoreTextChange++；
}
void InitListControl（）
{
如果（listBoxChild==null）
{
//查找父窗体-或继续查找，直到找到父窗体
ComboParentForm=this.Parent；
if（ComboParentForm！=null）
{
//设置消息过滤器，以便我们可以收听键盘
如果（！MsgFilterActive）
{
Application.AddMessageFilter（此）；
MsgFilterActive=true；
}
listBoxChild=listBoxChild=new ListBox（）；
listBoxChild.Visible=false；
listBoxChild.Click+=listBox1\u Click；
ComboParentForm.Controls.Add（listBoxChild）；
ComboParentForm.Controls.SetChildIndex（listBoxChild，0）；//放在前面
}
}
}
void ComboListMatcher_TextChanged（对象发送方，事件参数e）
{
如果（忽略文本更改>0）
{
IgnoreTextChange=0；
返回；
}
InitListControl（）；
如果（listBoxChild==null）
返回；
string SearchText=this.Text；
listBoxChild.Items.Clear（）；
//未键入任何内容时不显示列表
如果（！string.IsNullOrEmpty（SearchText））
{
foreach（此.Items中的字符串项）
{
if（Item！=null&&Item.Contains（SearchText、StringComparison.CurrentCultureIgnoreCase））
listBoxChild.Items.Add（Item）；
}
}
如果（listBoxChild.Items.Count>0）
{
Point PutItHere=新点（此.左，此.下）；
控制CONTROLTOMOVE=此；
PutItHere=this.Parent.PointToScreen（PutItHere）；
CONTROLTOMOVE=listBoxChild；
PutItHere=ComboParentForm.PointToClient（PutItHere）；
CONTROLTOMOVE.Show（）；
CONTROLTOMOVE.Left=PutItHere.X；
CONTROLTOMOVE.Top=PutItHere.Y；
CONTROLTOMOVE.WITH=此.WITH；
int TotalItemHeight=listBoxChild.ItemHeight*（listBoxChild.Items.Count+1）；
contoltomove.Height=Math.Min（ComboParentForm.ClientSize.Height-contoltomove.Top，TotalItemHeight）；
}
其他的
class ComboListMatcher : ComboBox, IMessageFilter
{
private Control ComboParentForm; // Or use type "Form"
private ListBox listBoxChild;
private int IgnoreTextChange;
private bool MsgFilterActive = false;
public ComboListMatcher()
{
// Set up all the events we need to handle
TextChanged += ComboListMatcher_TextChanged;
SelectionChangeCommitted += ComboListMatcher_SelectionChangeCommitted;
LostFocus += ComboListMatcher_LostFocus;
MouseDown += ComboListMatcher_MouseDown;
HandleDestroyed += ComboListMatcher_HandleDestroyed;
}
void ComboListMatcher_HandleDestroyed(object sender, EventArgs e)
{
if (MsgFilterActive)
Application.RemoveMessageFilter(this);
}
~ComboListMatcher()
{
}
private void ComboListMatcher_MouseDown(object sender, MouseEventArgs e)
{
HideTheList();
}
void ComboListMatcher_LostFocus(object sender, EventArgs e)
{
if (listBoxChild != null && !listBoxChild.Focused)
HideTheList();
}
void ComboListMatcher_SelectionChangeCommitted(object sender, EventArgs e)
{
IgnoreTextChange++;
}
void InitListControl()
{
if (listBoxChild == null)
{
// Find parent - or keep going up until you find the parent form
ComboParentForm = this.Parent;
if (ComboParentForm != null)
{
// Setup a messaage filter so we can listen to the keyboard
if (!MsgFilterActive)
{
Application.AddMessageFilter(this);
MsgFilterActive = true;
}
listBoxChild = listBoxChild = new ListBox();
listBoxChild.Visible = false;
listBoxChild.Click += listBox1_Click;
ComboParentForm.Controls.Add(listBoxChild);
ComboParentForm.Controls.SetChildIndex(listBoxChild, 0); // Put it at the front
}
}
}
void ComboListMatcher_TextChanged(object sender, EventArgs e)
{
if (IgnoreTextChange > 0)
{
IgnoreTextChange = 0;
return;
}
InitListControl();
if (listBoxChild == null)
return;
string SearchText = this.Text;
listBoxChild.Items.Clear();
// Don't show the list when nothing has been typed
if (!string.IsNullOrEmpty(SearchText))
{
foreach (string Item in this.Items)
{
if (Item != null && Item.Contains(SearchText, StringComparison.CurrentCultureIgnoreCase))
listBoxChild.Items.Add(Item);
}
}
if (listBoxChild.Items.Count > 0)
{
Point PutItHere = new Point(this.Left, this.Bottom);
Control TheControlToMove = this;
PutItHere = this.Parent.PointToScreen(PutItHere);
TheControlToMove = listBoxChild;
PutItHere = ComboParentForm.PointToClient(PutItHere);
TheControlToMove.Show();
TheControlToMove.Left = PutItHere.X;
TheControlToMove.Top = PutItHere.Y;
TheControlToMove.Width = this.Width;
int TotalItemHeight = listBoxChild.ItemHeight * (listBoxChild.Items.Count + 1);
TheControlToMove.Height = Math.Min(ComboParentForm.ClientSize.Height - TheControlToMove.Top, TotalItemHeight);
}
else
HideTheList();
}
/// <summary>
/// Copy the selection from the list-box into the combo box
/// </summary>
private void CopySelection()
{
if (listBoxChild.SelectedItem != null)
{
this.SelectedItem = listBoxChild.SelectedItem;
HideTheList();
this.SelectAll();
}
}
private void listBox1_Click(object sender, EventArgs e)
{
var ThisList = sender as ListBox;
if (ThisList != null)
{
// Copy selection to the combo box
CopySelection();
}
}
private void HideTheList()
{
if (listBoxChild != null)
listBoxChild.Hide();
}
public bool PreFilterMessage(ref Message m)
{
if (m.Msg == 0x201) // Mouse click: WM_LBUTTONDOWN
{
var Pos = new Point((int)(m.LParam.ToInt32() & 0xFFFF), (int)(m.LParam.ToInt32() >> 16));
var Ctrl = Control.FromHandle(m.HWnd);
if (Ctrl != null)
{
// Convert the point into our parent control's coordinates ...
Pos = ComboParentForm.PointToClient(Ctrl.PointToScreen(Pos));
// ... because we need to hide the list if user clicks on something other than the list-box
if (ComboParentForm != null)
{
if (listBoxChild != null &&
(Pos.X < listBoxChild.Left || Pos.X > listBoxChild.Right || Pos.Y < listBoxChild.Top || Pos.Y > listBoxChild.Bottom))
{
this.HideTheList();
}
}
}
}
else if (m.Msg == 0x100) // WM_KEYDOWN
{
if (listBoxChild != null && listBoxChild.Visible)
{
switch (m.WParam.ToInt32())
{
case 0x1B: // Escape key
this.HideTheList();
return true;
case 0x26: // up key
case 0x28: // right key
// Change selection
int NewIx = listBoxChild.SelectedIndex + ((m.WParam.ToInt32() == 0x26) ? -1 : 1);
// Keep the index valid!
if (NewIx >= 0 && NewIx < listBoxChild.Items.Count)
listBoxChild.SelectedIndex = NewIx;
return true;
case 0x0D: // return (use the currently selected item)
CopySelection();
return true;
}
}
}
return false;
}
}
private void Form1_Load(object sender, EventArgs e)
{
SqlConnection cn = new SqlConnection(@"server=.;database=My_dataBase;integrated security=true");
SqlDataAdapter da = new SqlDataAdapter(@"SELECT [MyColumn] FROM [my_table]", cn);
DataTable dt = new DataTable();
da.Fill(dt);
List<string> myList = new List<string>();
foreach (DataRow row in dt.Rows)
{
myList.Add((string)row[0]);
}
autoCompleteTextbox1.AutoCompleteList = myList;
}
private void autoCompleteTextbox_TextChanged(object sender, EventArgs e)
{
SqlConnection cn = new SqlConnection(@"server=.;database=My_dataBase;integrated security=true");
SqlDataAdapter da = new SqlDataAdapter(@"SELECT [MyColumn] FROM [my_table]", cn);
DataTable dt = new DataTable();
da.Fill(dt);
List<string> myList = new List<string>();
foreach (DataRow row in dt.Rows)
{
myList.Add((string)row[0]);
}
autoCompleteTextbox2.AutoCompleteList = myList;
}
using System;
using System.Data;
using System.Windows.Forms;
public partial class frmTestAutocomplete : Form
{
private DataTable maoCompleteList; //the data table from your data source
private string msDisplayCol = "name"; //displayed text
private string msIDcol = "id"; //ID or primary key
public frmTestAutocomplete(DataTable aoCompleteList, string sDisplayCol, string sIDcol)
{
InitializeComponent();
maoCompleteList = aoCompleteList
maoCompleteList.CaseSensitive = false; //turn off case sensitivity for searching
msDisplayCol = sDisplayCol;
msIDcol = sIDcol;
}
private void frmTestAutocomplete_Load(object sender, EventArgs e)
{
testCombo.DisplayMember = msDisplayCol;
testCombo.ValueMember = msIDcol;
testCombo.DataSource = maoCompleteList;
testCombo.SelectedIndexChanged += testCombo_SelectedIndexChanged;
testCombo.KeyUp += testCombo_KeyUp;
}
private void testCombo_KeyUp(object sender, KeyEventArgs e)
{
//use keyUp event, as text changed traps too many other evengts.
ComboBox oBox = (ComboBox)sender;
string sBoxText = oBox.Text;
DataRow[] oFilteredRows = maoCompleteList.Select(MC_DISPLAY_COL + " Like '%" + sBoxText + "%'");
DataTable oFilteredDT = oFilteredRows.Length > 0
? oFilteredRows.CopyToDataTable()
: maoCompleteList;
//NOW THAT WE HAVE OUR FILTERED LIST, WE NEED TO RE-BIND IT WIHOUT CHANGING THE TEXT IN THE ComboBox.
//1).UNREGISTER THE SELECTED EVENT BEFORE RE-BINDING, b/c IT TRIGGERS ON BIND.
testCombo.SelectedIndexChanged -= testCombo_SelectedIndexChanged; //don't select on typing.
oBox.DataSource = oFilteredDT; //2).rebind to filtered list.
testCombo.SelectedIndexChanged += testCombo_SelectedIndexChanged;
//3).show the user the new filtered list.
oBox.DroppedDown = true; //do this before repainting the text, as it changes the dropdown text.
//4).binding data source erases text, so now we need to put the user's text back,
oBox.Text = sBoxText;
oBox.SelectionStart = sBoxText.Length; //5). need to put the user's cursor back where it was.
}
private void testCombo_SelectedIndexChanged(object sender, EventArgs e)
{
ComboBox oBox = (ComboBox)sender;
if (oBox.SelectedValue != null)
{
MessageBox.Show(string.Format(@"Item #{0} was selected.", oBox.SelectedValue));
}
}
}
//=====================================================================================================
// code from frmTestAutocomplete.Designer.cs
//=====================================================================================================
partial class frmTestAutocomplete
{
/// <summary>
/// Required designer variable.
/// </summary>
private System.ComponentModel.IContainer components = null;
/// <summary>
/// Clean up any resources being used.
/// </summary>
/// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
protected override void Dispose(bool disposing)
{
if (disposing && (components != null))
{
components.Dispose();
}
base.Dispose(disposing);
}
#region Windows Form Designer generated code
/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
private void InitializeComponent()
{
this.testCombo = new System.Windows.Forms.ComboBox();
this.SuspendLayout();
//
// testCombo
//
this.testCombo.FormattingEnabled = true;
this.testCombo.Location = new System.Drawing.Point(27, 51);
this.testCombo.Name = "testCombo";
this.testCombo.Size = new System.Drawing.Size(224, 21);
this.testCombo.TabIndex = 0;
//
// frmTestAutocomplete
//
this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
this.ClientSize = new System.Drawing.Size(292, 273);
this.Controls.Add(this.testCombo);
this.Name = "frmTestAutocomplete";
this.Text = "frmTestAutocomplete";
this.Load += new System.EventHandler(this.frmTestAutocomplete_Load);
this.ResumeLayout(false);
}
#endregion
private System.Windows.Forms.ComboBox testCombo;
}