C#仿IE地址栏控件

using System;
using System.Collections;
using System.ComponentModel;
using System.Drawing;
using System.Data;
using System.Windows.Forms;

namespace Tools
{
///
/// UserControl1 的摘要说明。
///
public class TextBoxExt : System.Windows.Forms.TextBox
{
///
/// 必需的设计器变量。
///
private System.ComponentModel.Container components = null;

public TextBoxExt()
{
// 该调用是 Windows.Forms 窗体设计器所必需的。
InitializeComponent();

// TODO: 在 InitComponent 调用后添加任何初始化

}

///
/// 清理所有正在使用的资源。
///
protected override void Dispose( bool disposing )
{
if( disposing )
{
if( components != null )
components.Dispose();
}
base.Dispose( disposing );
}

#region 组件设计器生成的代码
///
/// 设计器支持所需的方法 - 不要使用代码编辑器
/// 修改此方法的内容。
///
private void InitializeComponent()
{
//
// TextBoxExt
//
this.KeyDown += new System.Windows.Forms.KeyEventHandler(this.TextBoxExt_KeyDown);
this.DoubleClick += new System.EventHandler(this.TextBoxExt_DoubleClick);
this.Leave += new System.EventHandler(this.TextBoxExt_Leave);
this.KeyUp += new System.Windows.Forms.KeyEventHandler(this.TextBoxExt_KeyUp);

}
#endregion
private System.Windows.Forms.ListBox m_lstShowChoice=null;
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();

}

}
//显示选择项目列表框的lstBox_MouseMove事件代码
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 设置提示框的外观
private Color m_lstForColor=System.Drawing.SystemColors.InfoText;
private Color m_lstBackColor=System.Drawing.SystemColors.Info;
private BorderStyle m_lstBordrStyle=System.Windows.Forms.BorderStyle.Fixed3D;
///
/// 设置/获取提示的背景色
///
public Color PromptBackColor
{
get
{
return m_lstBackColor;
}
set
{
m_lstBackColor=value;
ListBox box=this.lstPrompt;
if(box!=null)
box.BackColor=m_lstBackColor;
}
}

///
/// 设置/获取提示的前景色
///
public Color PromptForColor
{
get
{
return m_lstForColor;
}
set
{
m_lstForColor=value;
ListBox box=this.lstPrompt;
if(box!=null)
box.ForeColor=m_lstForColor;
}

}
///
/// 提示框的边框
///
public BorderStyle PromptBorderStyle
{
get
{
return m_lstBordrStyle;
}
set
{
m_lstBordrStyle=value;
ListBox box=this.lstPrompt;
if(box!=null)
box.BorderStyle=m_lstBordrStyle;
}
}
#endregion
private 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;
m_lstShowChoice.BackColor=this.m_lstBackColor;
m_lstShowChoice.BorderStyle=this.m_lstBordrStyle;
//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=m_lstShowChoice;
if(box!=null )
{
box.Items.Clear();
box.Items.AddRange(m_ForChoice.ToArray());
}
}
}
private bool m_AllowSpace=false;
///
/// 是否允许输入空格，这在信息录入时非常重要
/// 如许多人喜欢将两个字姓名中间插入空格来美观
/// 但给检索带来了不必要的麻烦
///
public bool AllowSpace
{
get
{
return m_AllowSpace;
}
set
{
m_AllowSpace=value;
}
}

private bool m_bChoiceOnly=false;

///
/// 是否只能选择,如果是,光标离开后检查输入是否在结果中
///
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;
}
///
/// 根据指定的字符串，筛选出可选项并加载到列表框中
///
/// 必须包含的字符串
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.m_ForChoice.ToArray());
else
{
foreach(string s in this.m_ForChoice)
{
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 (!m_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)
{
this.FillPrompt(strText);
if (!box.Visible)
{
if (box.Width != this.Width)
box.Width = this.Width;
box.Visible = true;
}
}
}
break;
}
}

private void TextBoxExt_Leave(object sender, System.EventArgs e)
{
//对于只选字段,必须输入同待选相匹配的值
if(this.m_bChoiceOnly)
{
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, System.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;
}
}
}
}