C#全角转换成半角并检查

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());

        }

    }

}