using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Data;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Collections;
namespace Tools
{
public class TextBoxExt : System.Windows.Forms.TextBox
{
//private System.ComponentModel.Container components = null;
private System.Windows.Forms.ListBox m_lstShowChoice = null;
public TextBoxExt()
{
this.Leave += new EventHandler(TextBoxExt_Leave);
this.KeyDown += new KeyEventHandler(TextBoxExt_KeyDown);
this.KeyUp += new KeyEventHandler(TextBoxExt_KeyUp);
this.DoubleClick += new EventHandler(TextBoxExt_DoubleClick);
}
private void lstBox_MouseUp(object sender, System.Windows.Forms.MouseEventArgs e)
{
ListBox box = (ListBox)sender;
if ((box.SelectedIndex > -1) && !this.ReadOnly)
{
this.Text = box.SelectedItem.ToString();
//选择后文本框失去了焦点，这里移回来
this.Focus();
}
}
private void lstBox_MouseMove(object sender, System.Windows.Forms.MouseEventArgs e)
{
ListBox box = (ListBox)sender;
Point pt = new Point(e.X, e.Y);
int n = box.IndexFromPoint(pt);
if (n >= 0)
box.SelectedIndex = n;
}
#region 设置提示框的背景
private Color m_lstForColor = System.Drawing.SystemColors.InfoText;
private Color m_lstBackColor = System.Drawing.SystemColors.InfoText;
/// <summary>
/// 设置/获取提示的背景色
/// </summary>
public Color PromptForeColor
{
get
{
return m_lstForColor;
}
set
{
m_lstForColor = value;
//lstPrompt的创建见下面的代码
ListBox box = this.lstPrompt;
if (box != null)
box.BackColor = m_lstForColor;
}
}
public Color PromptBackColor
{
get
{
return m_lstBackColor;
}
set
{
m_lstBackColor = value;
//lstPrompt的创建见下面的代码
ListBox box = this.lstPrompt;
if (box != null)
box.BackColor = m_lstBackColor;
}
}
#endregion
public System.Windows.Forms.ListBox lstPrompt
{
get
{
//如果没有列表用于显示提示的列表框，则创建一个
if ((m_lstShowChoice == null) && this.Parent != null)
{
m_lstShowChoice = new ListBox();
m_lstShowChoice.Visible = false;
m_lstShowChoice.Left = this.Left;
m_lstShowChoice.Top = this.Bottom;
m_lstShowChoice.Width = this.Width;
m_lstShowChoice.TabStop = false;
m_lstShowChoice.Sorted = true;
m_lstShowChoice.ForeColor = this.m_lstForColor; //前景
m_lstShowChoice.BackColor = this.m_lstBackColor; //背景（参见m_lstForColor的创建
m_lstShowChoice.BorderStyle = BorderStyle.FixedSingle;
//如果提示框过低，则显示到上面
if (m_lstShowChoice.Bottom > this.Parent.Height)
m_lstShowChoice.Top = this.Top - m_lstShowChoice.Height + 8;
m_lstShowChoice.MouseUp += new System.Windows.Forms.MouseEventHandler(this.lstBox_MouseUp);
m_lstShowChoice.MouseMove += new System.Windows.Forms.MouseEventHandler(this.lstBox_MouseMove);
this.Parent.Controls.Add(m_lstShowChoice);
this.Parent.ResumeLayout(false);
m_lstShowChoice.BringToFront();
}
return m_lstShowChoice;
}
}
private ArrayList m_ForChoice = new ArrayList();
public ArrayList ChoiceArray
{
get
{
return m_ForChoice;
}
set
{
m_ForChoice = (ArrayList)(value.Clone());
ListBox box = this.lstPrompt;
if (box != null)
{
box.Items.Clear();
box.Items.AddRange(m_ForChoice.ToArray());
}
}
}
private bool m_AllowSpace = false;
public bool AllowSpace
{
get
{
return m_AllowSpace;
}
set
{
m_AllowSpace = value;
}
}
private bool m_bChoiceOnly = false;
public bool ChoicOnly
{
get
{
return this.m_bChoiceOnly;
}
set
{
this.m_bChoiceOnly = value;
}
}
private int m_nOldPos = 0;
private bool bKeyDown = false;
private string m_strOldText = "";
private void TextBoxExt_KeyDown(object sender, System.Windows.Forms.KeyEventArgs e)
{
m_nOldPos = this.SelectionStart;
bKeyDown = true;
m_strOldText = this.Text;
}
private void FillPrompt(string p_strText)
{
ListBox box = this.lstPrompt;
if (box != null)
{
box.Items.Clear();
if (p_strText.Length == 0)//没有内容，显示全部
box.Items.AddRange(this.ChoiceArray.ToArray());
else
{
foreach (string s in this.ChoiceArray)
{
if (s.ToLower().IndexOf(p_strText.ToLower()) >= 0)
box.Items.Add(s);
}
}
}
}
private void TextBoxExt_KeyUp(object sender, System.Windows.Forms.KeyEventArgs e)
{
if (!bKeyDown)//忽略掉多余的KeyUp事件
return;
bKeyDown = false;
ListBox box = this.lstPrompt;
switch (e.KeyCode)
{
//通过上下箭头在待选框中移动
case System.Windows.Forms.Keys.Up:
case System.Windows.Forms.Keys.Down:
if ((box != null) && !this.Multiline)//多行文本通过上下箭头在两行之间移动
{
if ((e.KeyCode == System.Windows.Forms.Keys.Up) && (box.SelectedIndex > -1))//↑
box.SelectedIndex--;
else if ((e.KeyCode == System.Windows.Forms.Keys.Down) && (box.SelectedIndex < box.Items.Count - 1))//↑
box.SelectedIndex++;
//上下箭头不能移动当前光标，因此，还原原来位置
this.SelectionStart = m_nOldPos;
//显示提示框
if (!box.Visible)
{
if (box.Width != this.Width)
box.Width = this.Width;
box.Visible = true;
}
}
break;
case System.Windows.Forms.Keys.Escape://ESC隐藏提示
if ((box != null) && box.Visible)
box.Hide();
break;
case System.Windows.Forms.Keys.Return://回车选择一个或跳到下一控件
if ((box == null) || this.Multiline)
break;
//没有显示提示框时，移动到下一控件
if (!box.Visible)
{
SendKeys.Send("{TAB}");
}
else
{ //有提示，关闭提示{
if (box.SelectedIndex > -1)//有选择，使用当前选择的内容
this.Text = box.SelectedItem.ToString();
this.SelectionStart = this.Text.Length;
this.SelectAll();
box.Hide();
}
break;
default: //判断文本是否改变
string strText = this.Text;
//不允许产生空格，去掉文本中的空格
if (!this.AllowSpace)
strText = this.Text.Replace(" ", "");
int nStart = this.SelectionStart;
if (strText != m_strOldText)//文本有改变
{
//设置当前文本和键盘光标位置
this.Text = strText;
if (nStart > this.Text.Length)
nStart = this.Text.Length;
this.SelectionStart = nStart;
//修改可供选择的内容,并显示供选择的列表框
if (box != null)
{
FillPrompt(strText);
if (!box.Visible)
{
if (box.Width != this.Width)
box.Width = this.Width;
box.Visible = true;
}
}
}
break;
}
}
private void TextBoxExt_Leave(object sender, EventArgs e)
{
//对于只选字段,必须输入同待选相匹配的值
if (this.ChoicOnly)
{
int nIndex = this.ChoiceArray.IndexOf(this.Text);
if (nIndex < 0)
this.Text = "";
}
//失去焦点后，必须隐藏提示
ListBox box = this.lstPrompt;
if (box != null)
box.Visible = false;
}
private void TextBoxExt_DoubleClick(object sender, EventArgs e)
{
if (this.ReadOnly)
return;
ListBox box = this.lstPrompt;
if ((box != null) && (!box.Visible))
{
if (box.Width != this.Width)
box.Width = this.Width;
box.Visible = true;
}
}
}
}
调用
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Collections;
using Tools;
namespace MyTest
{
public partial class Form1 : Form
{
TextBoxExt txtbox1 = new TextBoxExt();
public Form1()
{
InitializeComponent();
this.Controls.Add(txtbox1);
txtbox1.PromptForeColor = Color.Gray;
txtbox1.PromptBackColor = Color.Snow;
}
private void Form1_Load(object sender, EventArgs e)
{
//创建一个数组，用于填充本控件的可选项
ArrayList arr = new ArrayList();
arr.Add("好好学习，天天消瘦");
arr.Add("bbbcccdddeeedsfdfd");
arr.Add("cdfdccddfdddedfdfeefffdfd");
arr.Add("ddfdsfddeeefffggg");
txtbox.ChoiceArray = arr;
}
}
}