C# 编写自定义 IP 输入框控件

    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;  
      
    namespace IP  
    {  
        public delegate void FallBackEvent(IpInputBox box,int flag);  
      
        public partial class Dialog : Form  
        {  
            public Dialog()  
            {  
                InitializeComponent();  
            }  
      
            private void Form1_Load(object sender,EventArgs e)  
            {  
                this.Controls.Add(ipBox);  
                ipBox.Location = new Point(10,10);  
            }  
      
            private IpInputBox ipBox = new IpInputBox(false);  
        }  
    }  

IpInputBox.cs 文件

    using System;  
    using System.Collections.Generic;  
    using System.Linq;  
    using System.Text;  
    using System.Windows.Forms;  
    using System.Drawing;  
      
    namespace IP  
    {  
        public class IpInputBox :TextBox  
        {  
            private bool _isNetmask = false;  
            public bool IsNetmask  
            {  
                get { return _isNetmask; }  
                set { _isNetmask = value; }  
            }  
            public IpInputBox(bool isNetmask)  
            {  
                _isNetmask = isNetmask;  
      
                this.Size = new System.Drawing.Size(150,25);  
      
                _dotLabel1.Text = ".";  
                _dotLabel2.Text = ".";  
                _dotLabel3.Text = ".";  
      
                _dotLabel1.Size = new System.Drawing.Size(10,25);  
                _dotLabel2.Size = new System.Drawing.Size(10,25);  
                _dotLabel3.Size = new System.Drawing.Size(10,25);  
      
                _box1.IsNetmask = _isNetmask;  
                _box2.IsNetmask = _isNetmask;  
                _box3.IsNetmask = _isNetmask;  
                _box4.IsNetmask = _isNetmask;  
      
                _box1.Flag = 1;  
                _box2.Flag = 2;  
                _box3.Flag = 3;  
                _box4.Flag = 4;  
      
      
                this.Controls.Add(_box1);  
                this.Controls.Add(_dotLabel1);  
      
      
                this.Controls.Add(_box2);  
                this.Controls.Add(_dotLabel2);  
      
      
                this.Controls.Add(_box3);  
                this.Controls.Add(_dotLabel3);  
      
                this.Controls.Add(_box4);  
      
                this.Font = new System.Drawing.Font(this.Font.Name,11);  
                _box1.Location = new System.Drawing.Point(-1,2);  
                _dotLabel1.Location = new System.Drawing.Point(29,2);  
                _box2.Location = new System.Drawing.Point(39,2);  
                _dotLabel2.Location = new System.Drawing.Point(69,2);  
                _box3.Location = new System.Drawing.Point(79,2);  
                _dotLabel3.Location = new System.Drawing.Point(109,2);  
                _box4.Location = new System.Drawing.Point(119,2);  
      
                _box1.Box = this;  
                _box2.Box = this;  
                _box3.Box = this;  
                _box4.Box = this;  
            }  
            public void FallBackEventFun(IpInputBox box,int flag)  
            {  
                switch (flag)  
                {  
                    case 1:  
                        _box1.Focus();  
                        break;  
                    case 2:  
                        _box1.Focus();  
                        break;  
                    case 3:  
                        _box2.Focus(); ;  
                        break;  
                    case 4:  
                        _box3.Focus(); ;  
                        break;  
                }  
            }  
      
            private string _ipAddress = string.Empty;  
            public void UpDateIpaddress()  
            {  
                try  
                {  
                    string[] sArray = ipAddress.Split(new char[] { '.' });  
                    _box1.Text = sArray[0];  
                    _box2.Text = sArray[1];  
                    _box3.Text = sArray[2];  
                    _box4.Text = sArray[3];  
                }  
                catch (Exception exp)  
                {  
                    MessageBox.Show("更新字符串失败:" + exp.Message);  
                }  
            }  
      
            /// <summary>  
            /// 获取ip地址  
            /// </summary>  
            public string IpAddressString  
            {  
                get  
                {  
                    string _ipStr1 = _box1.Text;  
                    string _ipStr2 = _box2.Text;  
                    string _ipStr3 = _box3.Text;  
                    string _ipStr4 = _box4.Text;  
                    string _ipDotStr = ".";  
                    _ipAddress = _ipStr1 + _ipDotStr + _ipStr2 + _ipDotStr + _ipStr3 + _ipDotStr + _ipStr4;  
                    return _ipAddress;  
                }  
                set  
                {  
                    _ipAddress = value;  
                }  
            }  
            private string ipAddress = string.Empty;  
      
            public string IpAddress  
            {  
                get { return ipAddress; }  
                set { ipAddress = value; }  
            }  
      
            private SubIpInputBox _box1 = new SubIpInputBox("");  
            private SubIpInputBox _box2 = new SubIpInputBox("");  
            private SubIpInputBox _box3 = new SubIpInputBox("");  
            private SubIpInputBox _box4 = new SubIpInputBox("");  
      
            private Label _dotLabel1 = new Label();  
            private Label _dotLabel2 = new Label();  
            private Label _dotLabel3 = new Label();  
      
        }  
    }  

SubIpInputBox.cs 文件

    using System;  
    using System.Collections.Generic;  
    using System.Linq;  
    using System.Text;  
    using System.Drawing;  
    using System.Windows.Forms;  
      
    namespace IP  
    {  
        public class SubIpInputBox:TextBox  
        {  
                /// <summary>  
                /// 判断是否是子网掩码,false表示ip地址,true表示子网掩码  
                /// </summary>  
                private bool _isNetmask = false;  
                private bool _isSendKey = false;  
                private System.ComponentModel.IContainer components;  
                private int _flag = 0;  
      
                public int Flag  
                {  
                    get { return _flag; }  
                    set { _flag = value; }  
                }  
      
                /// <summary>  
                ///   
                /// </summary>  
                public event FallBackEvent TextFallBackEvent;  
      
      
                //定义事件函数  
                public void FallBackEventFun(int flag)  
                {  
                    if (TextFallBackEvent != null)  
                    {  
                        TextFallBackEvent(box,this.Flag);  
                    }  
                }  
      
                public bool IsNetmask  
                {  
                    get { return _isNetmask; }  
                    set { _isNetmask = value; }  
                }  
      
                /// <summary>  
                /// 构造函数  
                /// </summary>  
                public SubIpInputBox(bool isNetmask)  
                {  
                    _isNetmask = isNetmask;  
                    box = new IpInputBox(_isNetmask);  
                    this.Font = new System.Drawing.Font(this.Font.Name,11);  
                    this.BorderStyle = System.Windows.Forms.BorderStyle.None;//去掉边框  
                    this.TextAlign = HorizontalAlignment.Center;//字体居中  
                    this.Size = new System.Drawing.Size(30,25);  
                    this.MaxLength = 3;  
                }  
      
                public SubIpInputBox(string str)  
                {  
                    this.Text = str;  
                    this.Size = new System.Drawing.Size(30,25);  
                    this.MaxLength = 3;  
                    this.BorderStyle = System.Windows.Forms.BorderStyle.None;//去掉边框  
                    this.TextAlign = HorizontalAlignment.Center;//字体居中  
                }  
      
                private IpInputBox box;  
                public IpInputBox Box  
                {  
                    get { return box; }  
                    set { box = value; }  
                }  
      
                protected override void OnKeyUp(KeyEventArgs e)  
                {  
                    base.OnKeyUp(e);  
      
      
                    if (this.Text == "")  
                    {  
                        if (e.KeyCode.ToString() == "Back")  
                        {  
                            this.TextFallBackEvent += new FallBackEvent(box.FallBackEventFun);  
                            this.FallBackEventFun(this.Flag);  
                        }  
                    }  
                }  
                protected override void OnKeyPress(KeyPressEventArgs e)  
                {  
                    base.OnKeyPress(e);  
      
                    //阻止从键盘输入键  
                    e.Handled = true;  
      
      
                    if ((e.KeyChar >= '0' && e.KeyChar <= '9') || (e.KeyChar == (char)8))  
                    {  
      
                        if ((e.KeyChar == (char)8))  
                        {  
                            e.Handled = false; return;  
                        }  
                        else  
                        {  
                            int len = this.Text.Length;  
                            if (len < 4)  
                            {  
                                if (len == 0 && e.KeyChar != '0')  
                                {  
                                    e.Handled = false; return;  
                                }  
                                else if (len == 0)  
                                {  
                                    if (this.Flag == 1 && this.IsNetmask == false)  
                                    {  
                                        return;  
                                    }  
                                }  
                                e.Handled = false; return;  
                            }  
                            else  
                            {  
                                // MessageBox.Show("编号最多只能输入3位数字！");  
                            }  
                        }  
                    }  
                    else if (e.KeyChar == '.')  
                    {  
                        //MessageBox.Show("编号只能输入数字！");  
                        if (this.Text.Length != 0)  
                        {  
                            // 如果输入 . 就执行 TAB 键   
                            SendKeys.SendWait("{TAB}");  
                        }  
                    }  
                    else if (this._isSendKey)  
                    {  
                        this.SelectAll();  
                    }  
      
                }  
      
      
                protected override void OnTextChanged(EventArgs e)  
                {  
      
                    try  
                    {  
                        string currentStr = this.Text;  
                        int currentNumber = Convert.ToInt32(currentStr);  
                        this.Text = currentNumber.ToString();  
                        this.SelectionStart = currentStr.Length;//设置光标在末尾  
                        if (_isNetmask == false)//表示ip地址  
                        {  
      
                            if (currentNumber > 223 || (currentNumber == 0 && this.Flag == 1))  
                            {  
                                MessageBox.Show("你输入的" + currentStr + "不是有效数值，请指定一个介于1到223之间的数值!","错误",MessageBoxButtons.OK,MessageBoxIcon.Warning);  
      
                                if (this.Flag == 1 && currentNumber == 0)  
                                {  
                                    this.Text = "1";  
                                }  
                                else  
                                {  
                                    this.Text = "223";  
                                }  
                                _isSendKey = true;  
                                this.Focus();  
                                this.SelectionStart = currentStr.Length;//设置光标在末尾  
                                this.SelectAll();  
                            }  
                            else  
                            {  
                                if (currentStr.Length == 3 && _isSendKey == false)  
                                {// 当输入的字符个数为3时，跳入另外一个输入框  
                                    //MessageBox.Show("输入完毕");  
                                    if (currentNumber == 0)  
                                    {  
                                        this.Text = "";  
                                        MessageBox.Show("000");  
                                    }  
                                    SendKeys.SendWait("{TAB}");  
                                }  
                            }  
      
                        }  
                        else//子网掩码  
                        {  
                            if (currentNumber > 255)  
                            {  
                                MessageBox.Show("你输入的" + currentStr + "不是有效数值，请指定一个介于0到255之间的数值!",MessageBoxIcon.Warning);  
                                this.Text = "255";  
                                this.Focus();  
                                this.SelectionStart = currentStr.Length;//设置光标在末尾  
                                this.SelectAll();  
                            }  
                            else  
                            {  
                                if (currentStr.Length == 3 && _isSendKey == false)  
                                {// 当输入的字符个数为3时，跳入另外一个输入框  
                                    //MessageBox.Show("输入完毕");  
                                    SendKeys.SendWait("{TAB}");  
      
                                }  
                            }  
                        }  
                    }  
                    catch  
                    {  
                        // 异常处理  
                    }  
                }  
      
                private void InitializeComponent()  
                {  
                    this.SuspendLayout();  
                    //   
                    // SubIpInputBox  
                    //   
                    this.TabIndexChanged += new System.EventHandler(this.SubTextBox_TabIndexChanged);  
                    this.ResumeLayout(false);  
                }  
                private void SubTextBox_TabIndexChanged(object sender,EventArgs e)  
                {  
      
                }  
        }  
    }  

来自：http://blog.csdn.net/taoerit/article/details/42535349