C#全角转换成半角并检查_.NET_编程开发_程序员俱乐部

新建一个项目quanbanjiao，在此项目下新建一个类Class1

 1 using System;
 2 using System.Web;
 3 using System.Text;
 4 
 5 namespace quanbanjiao
 6 {
 7     public class Class1
 8     {
 9         /**/
10         /// <summary>
11         /// 判断字符是否英文半角字符或标点
12         /// </summary>
13         /// <remarks>
14         /// 32    空格
15         /// 33-47    标点
16         /// 48-57    0~9
17         /// 58-64    标点
18         /// 65-90    A~Z
19         /// 91-96    标点
20         /// 97-122    a~z
21         /// 123-126  标点
22         /// </remarks>
23         public static bool IsBjChar(char c)
24         {
25             int i = (int)c;
26             return i >= 32 && i <= 126;
27         }
28 
29         /**/
30         /// <summary>
31         /// 判断字符是否全角字符或标点
32         /// </summary>
33         /// <remarks>
34         /// <para>全角字符 - 65248 = 半角字符</para>
35         /// <para>全角空格例外</para>
36         /// </remarks>
37         public static bool IsQjChar(char c)
38         {
39             if (c == '\u3000') return true;
40 
41             int i = (int)c - 65248;
42             if (i < 32) return false;
43             return IsBjChar((char)i);
44         }
45 
46         /* http://www.cnblogs.com/roucheng/ */
47         /// <summary>
48         /// 将字符串中的全角字符转换为半角
49         /// </summary>
50         public static string ToBj(string type,string s)
51         {
52             if (s == null || s.Trim() == string.Empty) return s;
53 
54             StringBuilder sb = new StringBuilder(s.Length);
55             for (int i = 0; i < s.Length; i++)
56             {
57                 if (s[i] == '\u3000')
58                     sb.Append('\u0020');
59                 else if (IsQjChar(s[i]))
60                     sb.Append((char)((int)s[i] - 65248));
61                 else
62                     sb.Append(s[i]);
63             }
64 
65             //如果是int类型的，则只能输入int类型，否则自动设为0
66 
67             if (type.ToLower() == "int")
68             {
69                 try
70                 {
71                     Convert.ToInt32(sb.ToString());
72                 }
73                 catch
74                 {
75                     return "0";
76                 }
77 
78             }
79 
80  
81 
82             //如果是float或double类型的，则只能输入这两种类型，否则自动设为0
83             if (type.ToLower() == "float" || type.ToLower() == "double")
84             {
85                 try
86                 {
87                     Convert.ToDouble(sb.ToString());
88                 }
89                 catch
90                 {
91                     return "0";
92                 }
93             }
94             return sb.ToString();
95         }
96     }
97 }

测试的例子：

using System;
using System.Web;
using quanbanjiao;//项目名称为quanbanjiao

namespace quanbanjiao
{
    public partial class WebForm1 : System.Web.UI.Page
    {
// keleyi.com
        protected void Page_Load(object sender, EventArgs e)
        {
        }

        protected void Button1_Click(object sender, EventArgs e)
        {
            TextBox1.Text = Class1.ToBj("string", TextBox1.Text.Trim());
        }
    }
}