C# 判断一个字符串是否数字开头

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;

using System.Text.RegularExpressions;

namespace WindowsFormsApplication1

{

public partial class Form1 : Form

{

public Form1()

{

InitializeComponent();

}

private void button1_Click(object sender, EventArgs e)

{

Regex regChina = new Regex("^[^\x00-\xFF]");

Regex regNum = new Regex("^[0-9]");

Regex regChar = new Regex("^[a-z]");

Regex regDChar = new Regex("^[A-Z]");

string str = "YL闫磊";

if (regNum.IsMatch(str))

{

MessageBox.Show("是数字");

}

else if (regChina.IsMatch(str))

{

MessageBox.Show("是中文");

}

else if (regChar.IsMatch(str))

{

MessageBox.Show("小写");

}

else if (regDChar.IsMatch(str))

{

MessageBox.Show("大写");

}

}

}

}