1 案一：Try...Catch(执行效率不高)
2 private bool IsNumberic(string oText)
3 {
4 try
5 {
6 int var1=Convert.ToInt32 (oText);
7 return true;
8 }
9 catch
10 {
11 return false;
12 }
13 }
14
15 方案二：正则表达式(推荐)
16 a)
17 public static bool IsNumeric(string value)
18 {
19 return Regex.IsMatch(value, @"^[+-]?\d*[.]?\d*$");
20 }
21 public static bool IsInt(string value)
22 {
23 return Regex.IsMatch(value, @"^[+-]?\d*$");
24 }
25 public static bool IsUnsign(string value)
26 {
27 return Regex.IsMatch(value, @"^\d*[.]?\d*$");
28 }
29 public static bool isTel(string strInput)
30 {
31 return Regex.IsMatch(strInput, @"\d{3}-\d{8}|\d{4}-\d{7}");
32 }
33 b)
34 using System;
35 using System.Text.RegularExpressions;
36 public bool IsNumber(String strNumber)
37 {
38 Regex objNotNumberPattern=new Regex("[^0-9.-]");
39 Regex objTwoDotPattern=new Regex("[0-9]*[.][0-9]*[.][0-9]*");
40 Regex objTwoMinusPattern=new Regex("[0-9]*[-][0-9]*[-][0-9]*");
41 String strValidRealPattern="^([-]|[.]|[-.]|[0-9])[0-9]*[.]*[0-9]+$";
42 String strValidIntegerPattern="^([-]|[0-9])[0-9]*$";
43 Regex objNumberPattern =new Regex("(" + strValidRealPattern +")|(" + strValidIntegerPattern + ")");
44 return !objNotNumberPattern.IsMatch(strNumber) &&
45 !objTwoDotPattern.IsMatch(strNumber) &&
46 !objTwoMinusPattern.IsMatch(strNumber) &&
47 objNumberPattern.IsMatch(strNumber);
48 }
49
50
51 方案三：遍历
52 a)
53 public bool isnumeric(string str)
54 {
55 char[] ch=new char[str.Length];
56 ch=str.ToCharArray();
57 for(int i=0;i {
58 if(ch[i]<48 || ch[i]>57)
59 return false;
60 }
61 return true;
62 }
63
64 b)
65 public bool IsInteger(string strIn) {
66 bool bolResult=true;
67 if(strIn=="") {
68 bolResult=false;
69 }
70 else {
71 foreach(char Char in strIn) {
72 if(char.IsNumber(Char))
73 continue;
74 else {
75 bolResult=false;
76 break;
77 }
78 }
79 }
80 return bolResult;
81 }
82 c)
83
84 public static bool isNumeric(string inString)
85 {
86 inString=inString.Trim();
87 bool haveNumber=false;
88 bool haveDot=false;
89 for(int i=0;i {
90 if (Char.IsNumber(inString[i]))
91 {
92 haveNumber=true;
93 }
94 else if(inString[i]=='.')
95 {
96 if (haveDot)
97 {
98 return false;
99 }
100 else
101 {
102 haveDot=true;
103 }
104 }
105 else if(i==0)
106 {
107 if(inString[i]!='+'&&inString[i]!='-')
108 {
109 return false;
110 }
111 }
112 else
113 {
114 return false;
115 }
116 if(i>20)
117 {
118 return false;
119 }
120 }
121 return haveNumber;
122 }
123
124
125 方案四：改写vb的IsNumeric源代码(执行效率不高)
126 //主调函数
127 public static bool IsNumeric(object Expression)
128 {
129 bool flag1;
130 IConvertible convertible1 = null;
131 if (Expression is IConvertible)
132 {
133 convertible1 = (IConvertible) Expression;
134 }
135 if (convertible1 == null)
136 {
137 if (Expression is char[])
138 {
139 Expression = new string((char[]) Expression);
140 }
141 else
142 {
143 return false;
144 }
145 }
146 TypeCode code1 = convertible1.GetTypeCode();
147 if ((code1 != TypeCode.String) && (code1 != TypeCode.Char))
148 {
149 return Utils.IsNumericTypeCode(code1);
150 }
151 string text1 = convertible1.ToString(null);
152 try
153 {
154 long num2;
155 if (!StringType.IsHexOrOctValue(text1, ref num2))
156 {
157 double num1;
158 return DoubleType.TryParse(text1, ref num1);
159 }
160 flag1 = true;
161 }
162 catch (Exception)
163 {
164 flag1 = false;
165 }
166 return flag1;
167 }//子函数
168 // return Utils.IsNumericTypeCode(code1);
169 internal static bool IsNumericTypeCode(TypeCode TypCode)
170 {
171 switch (TypCode)
172 {
173 case TypeCode.Boolean:
174 case TypeCode.Byte:
175 case TypeCode.Int16:
176 case TypeCode.Int32:
177 case TypeCode.Int64:
178 case TypeCode.Single:
179 case TypeCode.Double:
180 case TypeCode.Decimal:
181 {
182 return true;
183 }
184 case TypeCode.Char:
185 case TypeCode.SByte:
186 case TypeCode.UInt16:
187 case TypeCode.UInt32:
188 case TypeCode.UInt64:
189 {
190 break;
191 }
192 }
193 return false;
194 }
195
196 //-----------------
197 //StringType.IsHexOrOctValue(text1, ref num2))
198 internal static bool IsHexOrOctValue(string Value, ref long i64Value)
199 {
200 int num1;
201 int num2 = Value.Length;
202 while (num1 < num2)
203 {
204 char ch1 = Value[num1];
205 if (ch1 == '&')
206 {
207 ch1 = char.ToLower(Value[num1 + 1], CultureInfo.InvariantCulture);
208 string text1 = StringType.ToHalfwidthNumbers(Value.Substring(num1 + 2));
209 if (ch1 == 'h')
210 {
211 i64Value = Convert.ToInt64(text1, 0x10);
212 }
213 else if (ch1 == 'o')
214 {
215 i64Value = Convert.ToInt64(text1, 8);
216 }
217 else
218 {
219 throw new FormatException();
220 }
221 return true;
222 }
223 if ((ch1 != ' ') && (ch1 != '\u3000'))
224 {
225 return false;
226 }
227 num1++;
228 }
229 return false;
230 }
231 //----------------------------------------------------
232 // DoubleType.TryParse(text1, ref num1);
233 internal static bool TryParse(string Value, ref double Result)
234 {
235 bool flag1;
236 CultureInfo info1 = Utils.GetCultureInfo();
237 NumberFormatInfo info3 = info1.NumberFormat;
238 NumberFormatInfo info2 = DecimalType.GetNormalizedNumberFormat(info3);
239 Value = StringType.ToHalfwidthNumbers(Value, info1);
240 if (info3 == info2)
241 {
242 return double.TryParse(Value, NumberStyles.Any, info2, out Result);
243 }
244 try
245 {
246 Result = double.Parse(Value, NumberStyles.Any, info2);
247 flag1 = true;
248 }
249 catch (FormatException)
250 {
251 flag1 = double.TryParse(Value, NumberStyles.Any, info3, out Result);
252 }
253 catch (Exception)
254 {
255 flag1 = false;
256 }
257 return flag1;
258 }
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