正则表达式在程序设计中有着重要的位置，经常被用于处理字符串信息。
用Regex类的IsMatch方法，使用正则表达式可以验证电话号码是否合法。
一、涉及到的知识点
Regex类的IsMatch方法用于指示正则表达式使用pattern参数中指定的正则表达式是否在输入字符串中找到匹配项。语法格式如下：
public static bool IsMatch(string input,string patterm)参数说明
Input：字符串对象，表示要搜索匹配项的字符串。
Pattern：字符串对象，表示要匹配的正则表达式模式。
Bool：返回布尔值，如果正则表达式找到匹配项，则返回值为true，否则返回值为false。其中，正则表达式中匹配位置的元字符“^”。正则表达式中“^”用于匹配行首，如果正则表达式匹配以First开头的行，则正则表达式如下：^First。
如果电话号码的格式：xxx-xxxxxxxx，其中，x—代表数字，那么匹配的正则表达式是：^(\d{3,4}-)?\d{6,8}$。
如果密码有a-z、A-Z、0-9组成，并且至少一个大小写字母和数字，那么其正则表达式：[A-Za-z]+[0-9]；
如果密码有a-z、A-Z、0-9组成，并且至少一个大小写字母或数字，那么其正则表达式：[A-Za-z0-9]+，其中+有没有都可以；
如果把正则表达式改为[A-Z]+[a-z]+[0-9]，就变成依次至少一个大写、一个小写、一个数字了，打乱了顺序都不行。
由6位数字组成的邮编的正则表达式：^\d{6}$；
手机号码由11位数字组成，以1开头、第二位数字为3，4，5，6，7，8，9中一个、第三位到十一位数字为0到9的任意一个数字，其正则表达式：^1[3-9]\d{9}$；
18位身份号码是特征组合码，由十七位数字本体码和一位校验码组成。排列顺序从左至右依次为：六位数字地址码，八位数字出生日期码，三位数字顺序码和一位校验码。其中：
- 地址码：表示编码对象常住户口所在县(市、旗、区)的行政区划代码，按GB/T2260的规定执行。其中前两位为省份编码。
- 出生日期码：表示编码对象出生的年、月、日，按GB/T7408的规定执行，格式如20240130，之间不用分隔符。
- 顺序码：表示在同一地址码所标识的区域范围内，对同年、同月、同日出生的人编定的顺序号，顺序码的奇数分配给男性，偶数分配给女性。
- 校验码计算方式：
（1）对前17位数字本体码加权求和公式为：S = Sum(Ai * Wi), i = 1, ... , 17。其中Ai表示第i位置上的身份证号码数值；Wi表示第i位置上的加权因子，按位置依次为：7 9 10 5 8 4 2 1 6 3 7 9 10 5 8 4 2；
（2）以11对计算结果取模：Y = mod(S, 11)；
（3）根据模的值得到对应的校验码，对应关系为：
Y值：0 1 2 3 4 5 6 7 8 9 10
校验码：1 0 X 9 8 7 6 5 4 3 2
身份证号正则表达式：
//闰年
^[1-9]\d{5}(19|20)\d{2}((01|03|05|07|08|10|12)(0[1-9]|[1-2]\d|3[0-1])|(04|06|09|11)(0[1-9]|[1-2]\d|30)|02(0[1-9]|[1-2]\d))\d{3}[\dXx]$
//平年
^[1-9]\d{5}(19|20)\d{2}((01|03|05|07|08|10|12)(0[1-9]|[1-2]\d|3[0-1])|(04|06|09|11)(0[1-9]|[1-2]\d|30)|02(0[1-9]|1\d|2[0-8]))\d{3}[\dXx]$用正则表达式可以校验指定小数点后的位数是否匹配，比如验证小数点后位数是否2位的正则表达式：^[0-9]+(.\d{2})?$，^[0-9]+.\d{2}$，^[0-9]+\.\d{2}$，^[0-9]+\.[0-9]{2}$；
验证输入的数值是否有效的月份的正则表达式：^(0?[[1-9]1[0-2]]$，其中0?表示匹配零个或1个“0”，[1-9]表示匹配数字1～9，1[0-2]表示匹配数字10、11、12。
二、实例1：验证电话号码的格式
//使用正则表达式验证电话号码
namespace _070
{public partial class Form1 : Form{private Label? label1;private Label? label2;private Label? label3;private Button? button1;private TextBox? textBox1;public Form1(){InitializeComponent();Load += Form1_Load;}private void Form1_Load(object? sender, EventArgs e){// // label1// label1 = new Label{AutoSize = true,Location = new Point(36, 22),Name = "label1",Size = new Size(68, 17),TabIndex = 0,Text = "输入号码："};// // label2// label2 = new Label{AutoSize = true,Location = new Point(156, 49),Name = "label2",Size = new Size(79, 17),TabIndex = 1,Text = "xxx-xxxxxxxx"};// // label3// label3 = new Label{AutoSize = true,Location = new Point(36, 49),Name = "label3",Size = new Size(68, 17),TabIndex = 2,Text = "号码格式："};// // button1// button1 = new Button{Location = new Point(160, 76),Name = "button1",Size = new Size(75, 23),TabIndex = 3,Text = "号码验证",UseVisualStyleBackColor = true};button1.Click += Button1_Click;// // textBox1// textBox1 = new TextBox{Location = new Point(115, 16),Name = "textBox1",Size = new Size(120, 23),TabIndex = 4};// // Form1// AutoScaleDimensions = new SizeF(7F, 17F);AutoScaleMode = AutoScaleMode.Font;ClientSize = new Size(294, 111);Controls.Add(textBox1);Controls.Add(button1);Controls.Add(label3);Controls.Add(label2);Controls.Add(label1);Name = "Form1";StartPosition = FormStartPosition.CenterScreen;Text = "使用正则表达式验证电话号码";}/// <summary>/// 验证电话号码格式是否正确/// </summary>private void Button1_Click(object? sender, EventArgs e){if (!IsTelephone(textBox1!.Text)){ MessageBox.Show("电话号码格式不正确"); }else { MessageBox.Show("电话号码格式正确"); }}/// <summary>/// 验证电话号码格式是否匹配/// </summary>/// <param name="str_telephone">电话号码信息</param>/// <returns>方法返回布尔值</returns>public static bool IsTelephone(string str_telephone){return MyRegex().IsMatch(str_telephone);}[System.Text.RegularExpressions.GeneratedRegex(@"^(\d{3,4}-)?\d{6,8}$")]private static partial System.Text.RegularExpressions.Regex MyRegex();}
}
三、实例2：验证密码的格式
// 使用正则表达式验证密码格式
namespace _071
{public partial class Form1 : Form{private GroupBox? groupBox1;private Button? button1;private TextBox? textBox1;private Label? label1;public Form1(){InitializeComponent();Load += Form1_Load;}private void Form1_Load(object? sender, EventArgs e){// // button1// button1 = new Button{Location = new Point(171, 58),Name = "button1",Size = new Size(100, 23),TabIndex = 2,Text = "验证密码格式",UseVisualStyleBackColor = true};button1.Click += Button1_Click;// // textBox1// textBox1 = new TextBox{Location = new Point(126, 24),Name = "textBox1",Size = new Size(145, 23),TabIndex = 1};// // label1//label1 = new Label{AutoSize = true,Location = new Point(35, 30),Name = "label1",Size = new Size(68, 17),TabIndex = 0,Text = "输入密码："};// // groupBox1// groupBox1 = new GroupBox{Location = new Point(12, 12),Name = "groupBox1",Size = new Size(307, 87),TabIndex = 0,TabStop = false,Text = "密码必须由数字和大小写字母组成"};groupBox1.Controls.Add(button1);groupBox1.Controls.Add(textBox1);groupBox1.Controls.Add(label1);groupBox1.SuspendLayout();// // Form1// AutoScaleDimensions = new SizeF(7F, 17F);AutoScaleMode = AutoScaleMode.Font;ClientSize = new Size(331, 111);Controls.Add(groupBox1);Name = "Form1";StartPosition = FormStartPosition.CenterScreen;Text = "正则表达式验证密码格式";groupBox1.ResumeLayout(false);groupBox1.PerformLayout();}private void Button1_Click(object? sender, EventArgs e){if (!IsPassword(textBox1!.Text.Trim())){ MessageBox.Show("密码格式不正确!!!"); }else{MessageBox.Show("密码格式正确!!!!!");}}/// <summary>/// 验证码码输入条件/// </summary>/// <param name="str_password">密码字符串</param>/// <returns>返回布尔值</returns>public static bool IsPassword(string str_password){return MyRegex().IsMatch(str_password);}[System.Text.RegularExpressions.GeneratedRegex(@"[A-Za-z]+[0-9]")]//至少有一个字母，至少有一个数字//[System.Text.RegularExpressions.GeneratedRegex(@"[A-Z]+[a-z]+[0-9]")]//依次至少有一个大写一个小写一个//[System.Text.RegularExpressions.GeneratedRegex(@"[A-Za-z0-9]+")]//至少一个private static partial System.Text.RegularExpressions.Regex MyRegex();}
}
四、实例3：验证邮编的格式
// 用正则表达式验证邮编合法性
namespace _072
{public partial class Form1 : Form{private GroupBox? groupBox1;private TextBox? textBox1;private Button? button1;private Label? label1;public Form1(){InitializeComponent();Load += Form1_Load;}private void Form1_Load(object? sender, EventArgs e){// // textBox1// textBox1 = new TextBox{Location = new Point(139, 32),Name = "textBox1",Size = new Size(100, 23),TabIndex = 2};// // button1// button1 = new Button{Location = new Point(139, 61),Name = "button1",Size = new Size(100, 23),TabIndex = 1,Text = "验证邮编",UseVisualStyleBackColor = true};button1.Click += Button1_Click;// // label1// label1 = new Label{AutoSize = true,Location = new Point(55, 35),Name = "label1",Size = new Size(68, 17),TabIndex = 0,Text = "输入邮编："};// // groupBox1// groupBox1 = new GroupBox{Location = new Point(12, 12),Name = "groupBox1",Size = new Size(280, 98),TabIndex = 0,TabStop = false,Text = "验证邮编格式："};groupBox1.Controls.Add(textBox1);groupBox1.Controls.Add(button1);groupBox1.Controls.Add(label1);groupBox1.SuspendLayout();// // Form1// AutoScaleDimensions = new SizeF(7F, 17F);AutoScaleMode = AutoScaleMode.Font;ClientSize = new Size(304, 122);Controls.Add(groupBox1);Name = "Form1";StartPosition = FormStartPosition.CenterScreen;Text = "验证邮编格式合法性";groupBox1.ResumeLayout(false);groupBox1.PerformLayout();}private void Button1_Click(object? sender, EventArgs e){if (!IsPostalcode(textBox1!.Text)){ MessageBox.Show("邮政编号不正确!!!"); }else {MessageBox.Show("邮政编号正确!!!!!"); }}/// <summary>/// 验证邮编格式是否正确/// </summary>/// <param name="str_postalcode">邮编字符串</param>/// <returns>返回布尔值</returns>public static bool IsPostalcode(string str_postalcode){return MyRegex().IsMatch(str_postalcode);}[System.Text.RegularExpressions.GeneratedRegex(@"^\d{6}$")]private static partial System.Text.RegularExpressions.Regex MyRegex();}
}
五、实例4：验证手机号码的格式
//用正则表达式验证手机号码合法性
namespace _073
{public partial class Form1 : Form{private GroupBox? groupBox1;private Button? button1;private TextBox? textBox1;private Label? label1;public Form1(){InitializeComponent();Load += Form1_Load;}private void Form1_Load(object? sender, EventArgs e){// // button1// button1 = new Button{Location = new Point(129, 60),Name = "button1",Size = new Size(120, 23),TabIndex = 3,Text = "验证手机号码",UseVisualStyleBackColor = true};button1.Click += Button1_Click;// // textBox1// textBox1 = new TextBox{Location = new Point(129, 31),Name = "textBox1",Size = new Size(120, 23),TabIndex = 1};// // label1// label1 = new Label{AutoSize = true,Location = new Point(31, 37),Name = "label1",Size = new Size(92, 17),TabIndex = 0,Text = "输入手机号码："};// // groupBox1// groupBox1 = new GroupBox{Location = new Point(12, 12),Name = "groupBox1",Size = new Size(280, 92),TabIndex = 0,TabStop = false,Text = "验证手机号码"};groupBox1.Controls.Add(button1);groupBox1.Controls.Add(textBox1);groupBox1.Controls.Add(label1);groupBox1.SuspendLayout();// // Form1// AutoScaleDimensions = new SizeF(7F, 17F);AutoScaleMode = AutoScaleMode.Font;ClientSize = new Size(304, 122);Controls.Add(groupBox1);Name = "Form1";StartPosition = FormStartPosition.CenterScreen;Text = "验证手机号码合法性";groupBox1.ResumeLayout(false);groupBox1.PerformLayout();}private void Button1_Click(object? sender, EventArgs e){if (!IsHandset(textBox1!.Text)){ MessageBox.Show("手机号不正确!!!"); }else{MessageBox.Show("手机号正确!!!!!"); }}/// <summary>/// 验证手机号是否正确/// </summary>/// <param name="str_handset">手机号码字符串</param>/// <returns>返回布尔值</returns>public static bool IsHandset(string str_handset){return MyRegex().IsMatch(str_handset);}[System.Text.RegularExpressions.GeneratedRegex(@"^[1]+[3-9]+\d{9}$")]private static partial System.Text.RegularExpressions.Regex MyRegex();}
}
六、实例5：验证身份证号码的格式
// 用正则表达式验证身份证号码合法性
namespace _074
{public partial class Form1 : Form{private GroupBox? groupBox1;private Button? button1;private TextBox? textBox1;private Label? label1;public Form1(){InitializeComponent();Load += Form1_Load;}private void Form1_Load(object? sender, EventArgs e){// // label1// label1 = new Label{AutoSize = true,Location = new Point(16, 28),Name = "label1",Size = new Size(104, 17),TabIndex = 0,Text = "输入身份证号码："};// // textBox1// textBox1 = new TextBox{Location = new Point(125, 22),Name = "textBox1",Size = new Size(140, 23),TabIndex = 1};// // button1// button1 = new Button{Location = new Point(190, 57),Name = "button1",Size = new Size(75, 23),TabIndex = 2,Text = "验证",UseVisualStyleBackColor = true};button1.Click += Button1_Click;// // groupBox1// groupBox1 = new GroupBox{Location = new Point(12, 12),Name = "groupBox1",Size = new Size(280, 99),TabIndex = 0,TabStop = false,Text = "验证身份证号码"};groupBox1.Controls.Add(button1);groupBox1.Controls.Add(textBox1);groupBox1.Controls.Add(label1);groupBox1.SuspendLayout();// // Form1// AutoScaleDimensions = new SizeF(7F, 17F);AutoScaleMode = AutoScaleMode.Font;ClientSize = new Size(304, 123);Controls.Add(groupBox1);Name = "Form1";StartPosition = FormStartPosition.CenterScreen;Text = "验证身份证号码合法性";groupBox1.ResumeLayout(false);groupBox1.PerformLayout();}private void Button1_Click(object? sender, EventArgs e){if (!IsIDcard(textBox1!.Text.Trim())){ MessageBox.Show("身份证号不正确!!!");}else { MessageBox.Show("身份证号正确!!!!!"); }}/// <summary>/// 验证身份证号是否正确/// </summary>/// <param name="idcard">身份证号字符串</param>/// <returns>返回布尔值</returns>public static bool IsIDcard(string idcard){if (DateTime.IsLeapYear(Convert.ToInt32(idcard.Substring(6, 4)))){return MyRegex().IsMatch(idcard);}else{return MyRegex1().IsMatch(idcard);} }[System.Text.RegularExpressions.GeneratedRegex(@"(^[1-9]\d{5}(19|20)\d{2}((01|03|05|07|08|10|12)(0[1-9]|[1-2]\d|3[0-1])|(04|06|09|11)(0[1-9]|[1-2]\d|30)|02(0[1-9]|[1-2]\d))\d{3}[\dXx]$)")]private static partial System.Text.RegularExpressions.Regex MyRegex();[System.Text.RegularExpressions.GeneratedRegex(@"(^[1-9]\d{5}(19|20)\d{2}((01|03|05|07|08|10|12)(0[1-9]|[1-2]\d|3[0-1])|(04|06|09|11)(0[1-9]|[1-2]\d|30)|02(0[1-9]|1\d|2[0-8]))\d{3}[\dXx]$)")]private static partial System.Text.RegularExpressions.Regex MyRegex1();}
}
七、实例6：验证小数点后位数是否2位
// 验证小数点后是否为2位
namespace _075
{public partial class Form1 : Form{private GroupBox? groupBox1;private Button? button1;private TextBox? textBox1;private Label? label1;public Form1(){InitializeComponent();Load += Form1_Load;}private void Form1_Load(object? sender, EventArgs e){// // label1// label1 = new Label{AutoSize = true,Location = new Point(25, 30),Name = "label1",Size = new Size(68, 17),TabIndex = 0,Text = "输入小数："};// // textBox1// textBox1 = new TextBox{Location = new Point(121, 24),Name = "textBox1",Size = new Size(135, 23),TabIndex = 1};// // button1// button1 = new Button{Location = new Point(181, 59),Name = "button1",Size = new Size(75, 23),TabIndex = 2,Text = "验证",UseVisualStyleBackColor = true};button1.Click += Button1_Click;// // groupBox1// groupBox1 = new GroupBox{Location = new Point(12, 11),Name = "groupBox1",Size = new Size(280, 100),TabIndex = 0,TabStop = false,Text = "验证小数点后位数"};groupBox1.Controls.Add(button1);groupBox1.Controls.Add(textBox1);groupBox1.Controls.Add(label1);groupBox1.SuspendLayout();// // Form1// AutoScaleDimensions = new SizeF(7F, 17F);AutoScaleMode = AutoScaleMode.Font;ClientSize = new Size(304, 123);Controls.Add(groupBox1);Name = "Form1";StartPosition = FormStartPosition.CenterScreen;Text = "验证小数点后是否2位";groupBox1.ResumeLayout(false);groupBox1.PerformLayout();}private void Button1_Click(object? sender, EventArgs e){if (!IsDecimal(textBox1!.Text.Trim())){ MessageBox.Show("请输入两位小数!!!", "提示"); }else{ MessageBox.Show("输入正确!!!!!", "提示"); }}/// <summary>/// 验证小数是否正确/// 等效的正则：@"^[0-9]+\.\d{2}$"/// 等效的正则：@"^[0-9]+(.\d{2})$"/// 等效的正则：@"^[0-9]+.\d{2}$"/// 等效的正则：@"^[0-9]+\.[0-9]{2}$"/// </summary>/// <param name="str_decimal">小数字符串</param>/// <returns>返回布尔值</returns>public static bool IsDecimal(string str_decimal){return MyRegex().IsMatch(str_decimal);}[System.Text.RegularExpressions.GeneratedRegex(@"^[0-9]+(.\d{2})?$")]private static partial System.Text.RegularExpressions.Regex MyRegex();}
}
八、实例7：验证输入的数值是否有效月
// 用正则表达式验证输入的数字是否有效月
namespace _076
{public partial class Form1 : Form{private GroupBox? groupBox1;private Button? button1;private TextBox? textBox1;private Label? label1;public Form1(){InitializeComponent();Load += Form1_Load;}private void Form1_Load(object? sender, EventArgs e){// // label1// label1 = new Label{AutoSize = true,Location = new Point(34, 33),Name = "label1",Size = new Size(92, 17),TabIndex = 0,Text = "输入月份数值："};// // textBox1// textBox1 = new TextBox{Location = new Point(132, 30),Name = "textBox1",Size = new Size(100, 23),TabIndex = 1};// // button1// button1 = new Button{Location = new Point(157, 59),Name = "button1",Size = new Size(75, 23),TabIndex = 2,Text = "验证",UseVisualStyleBackColor = true};button1.Click += Button1_Click;// // groupBox1// groupBox1 = new GroupBox{Location = new Point(12, 11),Name = "groupBox1",Size = new Size(280, 100),TabIndex = 0,TabStop = false,Text = "验证是否有效的月"};groupBox1.Controls.Add(button1);groupBox1.Controls.Add(textBox1);groupBox1.Controls.Add(label1);groupBox1.SuspendLayout();// // Form1// AutoScaleDimensions = new SizeF(7F, 17F);AutoScaleMode = AutoScaleMode.Font;ClientSize = new Size(304, 123);Controls.Add(groupBox1);Name = "Form1";StartPosition = FormStartPosition.CenterScreen;Text = "验证数字是否有效月";groupBox1.ResumeLayout(false);groupBox1.PerformLayout();}private void Button1_Click(object? sender, EventArgs e){if (!IsMonth(textBox1!.Text.Trim())){MessageBox.Show("输入月份不正确!!!", "提示");}else{MessageBox.Show("输入信息正确!!!!!", "提示"); }}/// <summary>/// 验证月份是否正确/// </summary>/// <param name="str_Month">月份信息字符串</param>/// <returns>返回布尔值</returns>public static bool IsMonth(string str_Month){return MyRegex().IsMatch(str_Month);}[System.Text.RegularExpressions.GeneratedRegex(@"^(0?[[1-9]|1[0-2])$")]private static partial System.Text.RegularExpressions.Regex MyRegex();}
}
