学步园

控件创建过程：

解决方案->右键添加新项目->类库为Common->添加C_XML.cs类

C_XML.cs

using System;<br /> using System.Collections.Generic;<br /> using System.Text;<br /> using System.Xml;<br /> using System.Collections;</p> <p>namespace Common<br /> {<br /> /// <summary><br /> /// XML操作类<br /> /// </summary><br /> public class C_XML<br /> {</p> <p> private XmlDocument _doc;<br /> private string _filepath;</p> <p> public C_XML(string filepath)<br /> {<br /> _filepath = filepath;<br /> _doc = new XmlDocument();<br /> _doc.Load(_filepath);<br /> }</p> <p> /// <summary><br /> /// 返回doc<br /> /// </summary><br /> public XmlDocument XmlDoc<br /> {<br /> get<br /> {<br /> if (_doc != null)<br /> return _doc;<br /> else<br /> return null;<br /> }<br /> }</p> <p> /// <summary><br /> /// 根节点名称<br /> /// </summary><br /> public string Root<br /> {<br /> get<br /> {<br /> if (_doc.DocumentElement != null)<br /> {<br /> return _doc.DocumentElement.LocalName;<br /> }<br /> else<br /> {<br /> return null;<br /> }<br /> }<br /> }</p> <p> /// <summary><br /> /// 获取节点的第一个子集名称<br /> /// </summary><br /> public string RootFirst<br /> {<br /> get<br /> {<br /> if (_doc.DocumentElement.FirstChild != null)<br /> {<br /> return _doc.DocumentElement.FirstChild.LocalName;<br /> }<br /> else<br /> {<br /> return null;<br /> }<br /> }<br /> }</p> <p> /// <summary><br /> /// XML字节属性名称<br /> /// </summary><br /> public XmlAttributeCollection FirstChilesAttributes<br /> {<br /> get<br /> {<br /> if (_doc.DocumentElement.FirstChild.Attributes != null)<br /> {<br /> return _doc.DocumentElement.FirstChild.Attributes;<br /> }<br /> else<br /> {<br /> return null;<br /> }<br /> }<br /> }</p> <p> /// <summary><br /> /// 保存<br /> /// </summary><br /> public void Save()<br /> {<br /> _doc.Save(_filepath);<br /> }<br /> }<br /> }<br />

解决方案->右键添加新项目->windows控件库命名为DropDownTextBox

添加对Common的引用

添加information文件->创建info.xml文件

info.xml

<?xml version="1.0" encoding="utf-8" ?><br /> <root><br /> <information value="hello world!"></information><br /> </root>

DropDownTextBox.cs

 using System;<br /> using System.Collections.Generic;<br /> using System.ComponentModel;<br /> using System.Drawing;<br /> using System.Data;<br /> using System.Text;<br /> using System.Windows.Forms;<br /> using Common;<br /> using System.IO;<br /> using System.Xml;</p> <p>namespace DropDownTextBox<br /> {<br /> public partial class DropDownTextBox : UserControl<br /> {<br /> private Int32 _dropdowncount = 6;<br /> private Int32 _height;</p> <p> private Boolean _tem = false;<br /> private Common.C_XML _doc;<br /> private ListBox _listbox = new ListBox();</p> <p> public DropDownTextBox()<br /> {<br /> InitializeComponent();</p> <p> }</p> <p> /// <summary><br /> /// textbox记录信息数量<br /> /// </summary><br /> public Int32 DropDownCount<br /> {<br /> get {<br /> return _dropdowncount;<br /> }<br /> set { _dropdowncount = value; }<br /> }</p> <p> /// <summary><br /> /// textbox文本信息<br /> /// </summary><br /> public String Tb_Text<br /> {<br /> get { return tb_text.Text.Trim(); }<br /> }</p> <p> private void DropDownTextBox_Load(object sender, EventArgs e)<br /> {<br /> _doc = new C_XML(Path.GetFullPath("info.xml"));<br /> XmlNode _node = _doc.XmlDoc.SelectSingleNode(_doc.Root);</p> <p> if (_node.ChildNodes.Count > DropDownCount)<br /> {<br /> for (int i = 0; i < _node.ChildNodes.Count - DropDownCount;i++ )<br /> {<br /> _node.RemoveChild(_node.LastChild);<br /> }<br /> _doc.Save();<br /> }</p> <p> _height = (DropDownCount + 1) * 12;<br /> //<br /> // listBox1<br /> //<br /> this._listbox.Font = new System.Drawing.Font("宋体", 12F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Pixel);<br /> this._listbox.FormattingEnabled = true;<br /> this._listbox.ItemHeight = 12;<br /> this._listbox.Location = new System.Drawing.Point(this.Location.X, this.Location.Y + this.tb_text.Height - 1);<br /> this._listbox.Name = "_listbox";<br /> this._listbox.Size = new System.Drawing.Size(112, _height);<br /> this._listbox.TabIndex = 1;<br /> this._listbox.Visible = false;<br /> this._listbox.SelectedValueChanged += new System.EventHandler(this._listbox_SelectedValueChanged);</p> <p> Form parform = this.FindForm();<br /> parform.Controls.Add(this._listbox);<br /> this._listbox.BringToFront();<br /> }</p> <p> //查询XML文件<br /> private void tb_text_TextChanged(object sender, EventArgs e)<br /> {<br /> if (_tem && !_listbox.Visible)<br /> return;</p> <p> _doc = new C_XML(Path.GetFullPath("info.xml"));<br /> XmlNodeList nodelist = _doc.XmlDoc.SelectNodes(_doc.Root + "/" + _doc.RootFirst + "[contains(@" + _doc.FirstChilesAttributes[0].LocalName + ",'" + this.tb_text.Text.Trim() + "')]");</p> <p> if (nodelist.Count > 0)<br /> {<br /> _listbox.Items.Clear();<br /> foreach (XmlNode node in nodelist)<br /> {<br /> _listbox.Items.Add(node.Attributes[0].InnerText);<br /> }</p> <p> if (nodelist.Count < _dropdowncount * 12 / this._listbox.ItemHeight)<br /> this._listbox.Height = nodelist.Count * this._listbox.ItemHeight + 13;<br /> else<br /> this._listbox.Height = _height;</p> <p> this._listbox.Visible = true;<br /> }<br /> else<br /> {<br /> this._listbox.Visible = false;<br /> }<br /> }</p> <p> private void _listbox_SelectedValueChanged(object sender, EventArgs e)<br /> {<br /> if (!(_listbox.SelectedIndex < 0))<br /> {<br /> _listbox.Visible = false;<br /> _tem = true;<br /> this.tb_text.Text = _listbox.SelectedItem.ToString();<br /> _tem = false;<br /> }<br /> }<br /> }<br /> }

DropDownTextBox.Designer.cs

namespace DropDownTextBox<br /> {<br /> partial class DropDownTextBox<br /> {<br /> /// <summary><br /> /// 必需的设计器变量。<br /> /// </summary><br /> private System.ComponentModel.IContainer components = null;</p> <p> /// <summary><br /> /// 清理所有正在使用的资源。<br /> /// </summary><br /> /// <param name="disposing">如果应释放托管资源，为 true；否则为 false。</param><br /> protected override void Dispose(bool disposing)<br /> {<br /> if (disposing && (components != null))<br /> {<br /> components.Dispose();<br /> }<br /> base.Dispose(disposing);<br /> }</p> <p> #region 组件设计器生成的代码</p> <p> /// <summary><br /> /// 设计器支持所需的方法 - 不要<br /> /// 使用代码编辑器修改此方法的内容。<br /> /// </summary><br /> private void InitializeComponent()<br /> {<br /> this.tb_text = new System.Windows.Forms.TextBox();<br /> this.SuspendLayout();<br /> //<br /> // tb_text<br /> //<br /> this.tb_text.Dock = System.Windows.Forms.DockStyle.Left;<br /> this.tb_text.Location = new System.Drawing.Point(0, 0);<br /> this.tb_text.Name = "tb_text";<br /> this.tb_text.Size = new System.Drawing.Size(112, 21);<br /> this.tb_text.TabIndex = 0;<br /> this.tb_text.TextChanged += new System.EventHandler(this.tb_text_TextChanged);<br /> //<br /> // DropDownTextBox<br /> //<br /> this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 12F);<br /> this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;<br /> this.Controls.Add(this.tb_text);<br /> this.Name = "DropDownTextBox";<br /> this.Size = new System.Drawing.Size(112, 21);<br /> this.Load += new System.EventHandler(this.DropDownTextBox_Load);<br /> this.ResumeLayout(false);<br /> this.PerformLayout();</p> <p> }</p> <p> #endregion</p> <p> private System.Windows.Forms.TextBox tb_text;<br /> }<br /> }<br />

解决方案->右键添加新项目->windows应用程序命名为MyTest

Form1.cs

using System;<br /> using System.Collections.Generic;<br /> using System.ComponentModel;<br /> using System.Data;<br /> using System.Drawing;<br /> using System.Text;<br /> using System.Windows.Forms;<br /> using Common;<br /> using System.IO;<br /> using System.Xml;</p> <p>namespace MyTest<br /> {<br /> public partial class Form1 : Form<br /> {<br /> private C_XML _doc;</p> <p> public Form1()<br /> {<br /> InitializeComponent();<br /> _doc = new C_XML(Path.GetFullPath("info.xml"));<br /> dropDownTextBox1.DropDownCount = 6;<br /> }</p> <p> private void button1_Click(object sender, EventArgs e)<br /> {<br /> XmlNode _node = _doc.XmlDoc.SelectSingleNode(_doc.Root);<br /> if (_node.ChildNodes.Count >= dropDownTextBox1.DropDownCount)<br /> _node.RemoveChild(_node.LastChild);</p> <p> XmlElement information = _doc.XmlDoc.CreateElement(_doc.RootFirst);<br /> XmlAttribute newAttr = _doc.XmlDoc.CreateAttribute(_doc.FirstChilesAttributes[0].LocalName);<br /> newAttr.Value = this.dropDownTextBox1.Tb_Text;<br /> information.Attributes.Append(newAttr);<br /> _node.PrependChild(information);<br /> _doc.Save();</p> <p> }<br /> }<br /> }

Form1.Designer.cs

namespace MyTest<br /> {<br /> partial class Form1<br /> {<br /> /// <summary><br /> /// 必需的设计器变量。<br /> /// </summary><br /> private System.ComponentModel.IContainer components = null;</p> <p> /// <summary><br /> /// 清理所有正在使用的资源。<br /> /// </summary><br /> /// <param name="disposing">如果应释放托管资源，为 true；否则为 false。</param><br /> protected override void Dispose(bool disposing)<br /> {<br /> if (disposing && (components != null))<br /> {<br /> components.Dispose();<br /> }<br /> base.Dispose(disposing);<br /> }</p> <p> #region Windows 窗体设计器生成的代码</p> <p> /// <summary><br /> /// 设计器支持所需的方法 - 不要<br /> /// 使用代码编辑器修改此方法的内容。<br /> /// </summary><br /> private void InitializeComponent()<br /> {<br /> this.button1 = new System.Windows.Forms.Button();<br /> this.dropDownTextBox1 = new DropDownTextBox.DropDownTextBox();<br /> this.SuspendLayout();<br /> //<br /> // button1<br /> //<br /> this.button1.Location = new System.Drawing.Point(268, 207);<br /> this.button1.Name = "button1";<br /> this.button1.Size = new System.Drawing.Size(75, 23);<br /> this.button1.TabIndex = 3;<br /> this.button1.Text = "button1";<br /> this.button1.UseVisualStyleBackColor = true;<br /> this.button1.Click += new System.EventHandler(this.button1_Click);<br /> //<br /> // dropDownTextBox1<br /> //<br /> this.dropDownTextBox1.DropDownCount = 6;<br /> this.dropDownTextBox1.Location = new System.Drawing.Point(252, 88);<br /> this.dropDownTextBox1.Name = "dropDownTextBox1";<br /> this.dropDownTextBox1.Size = new System.Drawing.Size(112, 21);<br /> this.dropDownTextBox1.TabIndex = 2;<br /> //<br /> // Form1<br /> //<br /> this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 12F);<br /> this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;<br /> this.ClientSize = new System.Drawing.Size(607, 392);<br /> this.Controls.Add(this.dropDownTextBox1);<br /> this.Controls.Add(this.button1);<br /> this.Name = "Form1";<br /> this.Text = "Form1";<br /> this.ResumeLayout(false);</p> <p> }</p> <p> #endregion</p> <p> private DropDownTextBox.DropDownTextBox dropDownTextBox1;<br /> private System.Windows.Forms.Button button1;</p> <p> }<br /> }</p> <p>

源码下载地址：http://download.csdn.net/source/1113501