用写C#写的一个IP输入框控件

using System; 
using System.Collections.Generic; 
using System.Text; 

namespace IpBox 
{ 
    using System; 
    using System.Collections; 
    using System.ComponentModel; 
    using System.Drawing; 
    using System.Data; 
    using System.Windows.Forms; 
    using System.Text.RegularExpressions; 

    public class IpBox : System.Windows.Forms.UserControl 
    { 
        private System.Windows.Forms.Panel panel1; 
        private System.Windows.Forms.TextBox textBox4; 
        private System.Windows.Forms.Label label3; 
        private System.Windows.Forms.TextBox textBox3; 
        private System.Windows.Forms.Label label2; 
        private System.Windows.Forms.TextBox textBox2; 
        private System.Windows.Forms.Label label1; 
        private System.Windows.Forms.TextBox textBox1; 
        private string _text = ""; 
         
        private System.ComponentModel.Container components = null; 

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

            // TODO: 在 InitializeComponent 调用后添加任何初始化 

        } 

         
        protected override void Dispose(bool disposing) 
        { 
            if (disposing) 
            { 
                if (components != null) 
                { 
                    components.Dispose(); 
                } 
            } 
            base.Dispose(disposing); 
        } 

        组件设计器生成的代码#region 组件设计器生成的代码 
      
        private void InitializeComponent() 
        { 
            this.panel1 = new System.Windows.Forms.Panel(); 
            this.textBox4 = new System.Windows.Forms.TextBox(); 
            this.label3 = new System.Windows.Forms.Label(); 
            this.textBox3 = new System.Windows.Forms.TextBox(); 
            this.label2 = new System.Windows.Forms.Label(); 
            this.textBox2 = new System.Windows.Forms.TextBox(); 
            this.label1 = new System.Windows.Forms.Label(); 
            this.textBox1 = new System.Windows.Forms.TextBox(); 
            this.panel1.SuspendLayout(); 
            this.SuspendLayout(); 
            //  
            // panel1 
            //  
            this.panel1.BackColor = System.Drawing.Color.White; 
            this.panel1.BorderStyle = System.Windows.Forms.BorderStyle.Fixed3D; 
            this.panel1.Controls.Add(this.textBox4); 
            this.panel1.Controls.Add(this.label3); 
            this.panel1.Controls.Add(this.textBox3); 
            this.panel1.Controls.Add(this.label2); 
            this.panel1.Controls.Add(this.textBox2); 
            this.panel1.Controls.Add(this.label1); 
            this.panel1.Controls.Add(this.textBox1); 
            this.panel1.Location = new System.Drawing.Point(0, 0); 
            this.panel1.Name = "panel1"; 
            this.panel1.Size = new System.Drawing.Size(136, 20); 
            this.panel1.TabIndex = 1; 
            //  
            // textBox4 
            //  
            this.textBox4.BorderStyle = System.Windows.Forms.BorderStyle.None; 
            this.textBox4.Location = new System.Drawing.Point(104, 0); 
            this.textBox4.MaxLength = 3; 
            this.textBox4.Name = "textBox4"; 
            this.textBox4.Size = new System.Drawing.Size(20, 14); 
            this.textBox4.TabIndex = 6; 
            this.textBox4.TextAlign = System.Windows.Forms.HorizontalAlignment.Center; 
            this.textBox4.KeyPress += new System.Windows.Forms.KeyPressEventHandler(this.textBox4_KeyPress); 
            //  
            // label3 
            //  
            this.label3.Location = new System.Drawing.Point(96, 0); 
            this.label3.Name = "label3"; 
            this.label3.Size = new System.Drawing.Size(8, 14); 
            this.label3.TabIndex = 5; 
            this.label3.Text = "."; 
            this.label3.TextAlign = System.Drawing.ContentAlignment.TopCenter; 
            //  
            // textBox3 
            //  
            this.textBox3.BorderStyle = System.Windows.Forms.BorderStyle.None; 
            this.textBox3.Location = new System.Drawing.Point(72, 0); 
            this.textBox3.MaxLength = 3; 
            this.textBox3.Name = "textBox3"; 
            this.textBox3.Size = new System.Drawing.Size(20, 14); 
            this.textBox3.TabIndex = 4; 
            this.textBox3.TextAlign = System.Windows.Forms.HorizontalAlignment.Center; 
            this.textBox3.KeyPress += new System.Windows.Forms.KeyPressEventHandler(this.textBox3_KeyPress); 
            //  
            // label2 
            //  
            this.label2.Location = new System.Drawing.Point(64, 0); 
            this.label2.Name = "label2"; 
            this.label2.Size = new System.Drawing.Size(8, 14); 
            this.label2.TabIndex = 3; 
            this.label2.Text = "."; 
            this.label2.TextAlign = System.Drawing.ContentAlignment.TopCenter; 
            //  
            // textBox2 
            //  
            this.textBox2.BorderStyle = System.Windows.Forms.BorderStyle.None; 
            this.textBox2.Location = new System.Drawing.Point(40, 0); 
            this.textBox2.MaxLength = 3; 
            this.textBox2.Name = "textBox2"; 
            this.textBox2.Size = new System.Drawing.Size(20, 14); 
            this.textBox2.TabIndex = 2; 
            this.textBox2.TextAlign = System.Windows.Forms.HorizontalAlignment.Center; 
            this.textBox2.KeyPress += new System.Windows.Forms.KeyPressEventHandler(this.textBox2_KeyPress); 
            //  
            // label1 
            //  
            this.label1.Location = new System.Drawing.Point(32, 0); 
            this.label1.Name = "label1"; 
            this.label1.Size = new System.Drawing.Size(8, 14); 
            this.label1.TabIndex = 1; 
            this.label1.Text = "."; 
            this.label1.TextAlign = System.Drawing.ContentAlignment.TopCenter; 
            //  
            // textBox1 
            //  
            this.textBox1.BorderStyle = System.Windows.Forms.BorderStyle.None; 
            this.textBox1.Location = new System.Drawing.Point(8, 0); 
            this.textBox1.MaxLength = 3; 
            this.textBox1.Name = "textBox1"; 
            this.textBox1.Size = new System.Drawing.Size(20, 14); 
            this.textBox1.TabIndex = 0; 
            this.textBox1.TextAlign = System.Windows.Forms.HorizontalAlignment.Center; 
            this.textBox1.KeyPress += new System.Windows.Forms.KeyPressEventHandler(this.textBox1_KeyPress); 
            //  
            // IpBox 
            //  
            this.Controls.Add(this.panel1); 
            this.Name = "IpBox"; 
            this.Size = new System.Drawing.Size(136, 20); 
            this.panel1.ResumeLayout(false); 
            this.panel1.PerformLayout(); 
            this.ResumeLayout(false); 

        } 
        #endregion 

        private void textBox1_KeyDown(object sender, System.Windows.Forms.KeyEventArgs e) 
        { 
            //System.Text.Encoding.GetEncoding(0).GetString(); 
        } 

        private void textBox1_KeyPress(object sender, System.Windows.Forms.KeyPressEventArgs e) 
        { 
            MaskIpAddr(textBox1, e); 
        } 

        private void textBox2_KeyPress(object sender, System.Windows.Forms.KeyPressEventArgs e) 
        { 
            MaskIpAddr(textBox2, e); 
        } 

        private void textBox3_KeyPress(object sender, System.Windows.Forms.KeyPressEventArgs e) 
        { 
            MaskIpAddr(textBox3, e); 
        } 

        private void textBox4_KeyPress(object sender, System.Windows.Forms.KeyPressEventArgs e) 
        { 
            MaskIpAddr(textBox4, e); 
        } 

        private void MaskIpAddr(System.Windows.Forms.TextBox textBox, KeyPressEventArgs e) 
        { 
            int len = textBox.Text.Length; 

            if (Char.IsDigit(e.KeyChar) || e.KeyChar == '.' || e.KeyChar == 8) 
            { 
                if (e.KeyChar != 8) 
                { 
                    if (len == 2 && e.KeyChar != '.') 
                    { 
                        string tmp = textBox.Text + e.KeyChar; 
                        if (textBox.Name == "textBox1") 
                        { 
                            if (Int32.Parse(tmp) > 223) // 进行验证 
                            { 
                                MessageBox.Show(tmp + " 不是一个有效项目。请指定一个介于 1 和 223 之间的数值。"); 
                                textBox.Text = "223"; 
                                textBox.Focus(); 
                                return; 
                            } 

                            textBox2.Focus(); 
                            textBox2.SelectAll(); 

                        } 
                        else if (textBox.Name == "textBox2") 
                        { 
                            if (Int32.Parse(tmp) > 255) 
                            { 
                                MessageBox.Show(tmp + " 不是一个有效项目。请指定一个介于 1 和 255 之间的数值。"); 
                                textBox.Text = "255"; 
                                textBox.Focus(); 
                                return; 
                            } 
                            textBox3.Focus(); 
                            textBox3.SelectAll(); 
                        } 
                        else if (textBox.Name == "textBox3") 
                        { 
                            if (Int32.Parse(tmp) > 255) 
                            { 
                                MessageBox.Show(tmp + " 不是一个有效项目。请指定一个介于 1 和 255 之间的数值。"); 
                                textBox.Text = "255"; 
                                textBox.Focus(); 
                                return; 
                            } 
                            textBox4.Focus(); 
                            textBox4.SelectAll(); 
                        } 
                        else if (textBox.Name == "textBox4") 
                        { 
                            if (Int32.Parse(tmp) > 255) 
                            { 
                                MessageBox.Show(tmp + " 不是一个有效项目。请指定一个介于 1 和 255 之间的数值。"); 
                                textBox.Text = "255"; 
                                textBox.Focus(); 
                                return; 
                            } 

                        } 

                    } 
                    if (e.KeyChar == '.') 
                    { 
                        if (textBox.Name == "textBox1" && textBox.Text != "") 
                        { 
                            textBox2.Focus(); 
                            textBox2.SelectAll(); 
                        } 
                        if (textBox.Name == "textBox2" && textBox.Text != "") 
                        { 
                            textBox3.Focus(); 
                            textBox3.SelectAll(); 
                        } 
                        if (textBox.Name == "textBox3" && textBox.Text != "") 
                        { 
                            textBox4.Focus(); 
                            textBox4.SelectAll(); 
                        } 
                        if (textBox.Name == "textBox4" && textBox.Text != "") 
                        { 

                        } 
                        e.Handled = true; 
                    } 
                } 
                else 
                { 
                    if (textBox.Name == "textBox1" && textBox.Text == "") 
                    { 

                    } 
                    if (textBox.Name == "textBox2" && textBox.Text == "") 
                    { 
                        textBox1.Focus(); 
                        textBox1.SelectionStart = textBox1.Text.Length; 
                    } 
                    if (textBox.Name == "textBox3" && textBox.Text == "") 
                    { 
                        textBox2.Focus(); 
                        textBox2.SelectionStart = textBox2.Text.Length; 
                    } 
                    if (textBox.Name == "textBox4" && textBox.Text == "") 
                    { 
                        textBox3.Focus(); 
                        textBox3.SelectionStart = textBox3.Text.Length; 
                    } 
                    e.Handled = false; 
                } 
            } 
            else 
                e.Handled = true; 
        } 


        [Browsable(true)] 
         
        // 获取 IpBox 的文本。 
         
        public new string Text 
        { 
            get 
            { 
                if (textBox1.Text == "" 
                 || textBox2.Text == "" 
                 || textBox3.Text == "" 
                 || textBox4.Text == "") 
                { 
                    _text = ""; 
                    return _text; 
                } 
                else 
                { 
                    _text = Convert.ToInt32(textBox1.Text).ToString() + "." + Convert.ToInt32(textBox2.Text).ToString() + "." + Convert.ToInt32(textBox3.Text).ToString() + "." + Convert.ToInt32(textBox4.Text).ToString(); 
                    return _text; 
                } 

            } 
            /**//* set  //  
             { 
              if(value != null) 
              { 
               // 255-255-255-255 
               //string pattern = @"^([1-9]|\d{2}|1[0-9]{1,2}|2[0-5]{2})\.(\d{1,2}|1[0-9]{1,2}|[1-2][0-5]{2})\.(\d{1,2}|1[0-9]{1,2}|[1-2][0-5]{2})\.(\d{1,2}|1[0-9]{1,2}|[1-2][0-5]{2})$"; 
               // 223-255-255-255 
               string pattern = @"^([1-9]|\d{2}|1[0-9]{1,2}|2[1-2][1-3])\.(\d{1,2}|1[0-9]{1,2}|[1-2][0-5]{2})\.(\d{1,2}|1[0-9]{1,2}|[1-2][0-5]{2})\.(\d{1,2}|1[0-9]{1,2}|[1-2][0-5]{2})$"; 

               if( !Regex.IsMatch(value , pattern) ) 
               { 
                _text = ""; 
                throw new Exception("IP 地址格式错误！"); 
               } 
               else 
               { 
                string[] ipnum = value.Split('.'); 
                textBox1.Text = ipnum[0]; 
                textBox2.Text = ipnum[1]; 
                textBox3.Text = ipnum[2]; 
                textBox4.Text = ipnum[3]; 
               } 
              } 

              _text = value; 

             } 
            */ 

        } 

    } 
}