C#程序提取中文首字母转换方法

C# GUI的：

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;

namespace WindowsApplication22
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            string str = textBox1.Text;
            MessageBox.Show(GetPYString(str));
        }
        public string GetPYString(string str)
        {
            string tempStr = "";
            foreach (char c in str)//当前在text里的中文
            {
                if ((int)c >= 33 && (int)c <= 126)