usercontrol1.cs

能够模仿IE地址栏控件,完成自动筛选功能

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

namespace Tools
{

	public class TextBoxExt : System.Windows.Forms.TextBox

	{
		
		private System.ComponentModel.Container components = null;
		private System.Windows.Forms.ListBox m_lstShowChoice=null;
		

		//构造函数中订阅事件
		public TextBoxExt()

		{
			this.KeyUp+=new KeyEventHandler(TextBoxExt_KeyUp);
			this.KeyDown+=new KeyEventHandler(TextBoxExt_KeyDown);
			this.Leave +=new EventHandler(TextBoxExt_Leave);
			this.DoubleClick+=new EventHandler(TextBoxExt_DoubleClick);
		}



		/// <summary>
		/// 清理所有正在使用的资源。
		/// </summary>
		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
		/// <summary>
		/// 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。
		/// </summary>
		private void InitializeComponent()
		{
			components = new System.ComponentModel.Container();
			//m_lstShowChoice.MouseUp += new System.Windows.Forms.MouseEventHandler(this.lstBox_MouseUp);
			/*this.KeyUp+=new KeyEventHandler(TextBoxExt_KeyUp);
			this.KeyDown+=new KeyEventHandler(TextBoxExt_KeyDown);
			this.Leave +=new EventHandler(TextBoxExt_Leave);
			this.DoubleClick+=new EventHandler(TextBoxExt_DoubleClick);*/
		}
		#endregion
		//响应列表框鼠标的MouseUp事件，也就是用户通过单击列表框进行选择
		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(); 

			}

		}
		//当用户在列表框中移动鼠标时，根据鼠标位置，自动设置列表框当前项
		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.Info;
		//private BorderStyle m_lstBordrStyle=System.Drawing.SystemColors.InactiveBorder;
		private BorderStyle m_lstBordrStyle=System.Windows.Forms.BorderStyle.Fixed3D;

		/// <summary>

		/// 设置/获取提示的背景色

		/// </summary>
		public BorderStyle PromptBordrStyle
		{
			get
			{
				return m_lstBordrStyle;
			}
			set
			{
				m_lstBordrStyle=value;
				ListBox box=this.lstPrompt;
				if(box!=null)
					box.BorderStyle=m_lstBordrStyle;
			}
		}
		public Color PromptForColor
		{
			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.ForeColor=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
		
		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.Visible=true;

					m_lstShowChoice.Left=this.Left;

					m_lstShowChoice.Top=this.Bottom;

					m_lstShowChoice.Width=this.Width;

					m_lstShowChoice.Height=this.Height*2;//高度是TextBoxExt的倍数

					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=this.m_lstBordrStyle; //边框，背景（参见m_lstForColor的创建

 

					//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();
					//m_lstShowChoice.Visible=true;

				}

				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());

				}

			}

		}

		//设置一个“性质”来决定是否允许用户输入空格
		private bool m_AllowSpace=false;

		public bool AllowSpace

		{

			get

			{

				return m_AllowSpace;

			}

			set

			{

				m_AllowSpace=value;

			}

		}

		//允许用户输入，光标离开本文本框时，进行检查，判断用户输入的内容是否在可选项内，如果不在，则清空用户输入
		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;

		}

		//创建一个函数，用来根据文本框当前内容，从可供选择的m_ForChoice数组中筛选出模糊匹配的选项，添加到列表框中
		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;

			}

		}

		//当文本框失去键盘光标后，必须隐藏提示，对于只选型文本框，还要判断用户输入是否在可选项中
		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;

		}

		//响应双击事件
		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;      
			}
		}		
	}
}