C # method to verify whether the input is numeric

In fact, you can use regular expressions
static bool IsNumeric (String str)
{
if (Str==null | |) str. length==0)
return false;
foreach (char c in str)
{
if (! Char.isnumber (c))
{
return false;
}
}
return true;
}

Regular expressions are written in the following way:


static bool IsNumeric (String str)
{
System.Text.RegularExpressions.Regex REG1
= new System.Text.RegularExpressions.Regex (@ "^[-]?\d+[.")? \d*$ ");
Return REG1. IsMatch (str);
}


In fact, the most single is the function in vb.net, the following code snippet
Using Microsoft.VisualBasic

Information.isnumeric (Str_input)
Returns TRUE or FALSE to determine whether a number
However, it is necessary to add-lmicrosoft.visualbasic at compile time to compile successfully
CSDN Netizen (2005-11-24)
What if it's done directly?
try{
Float F=float.parse (temp);
}
catch (Exception ex)
{
MessageBox.Show ("This is not a number");
}
Dancefire (2005-11-13)
I think the regular expression is not correct, leading 0 in front of the decimal point should allow omitting, 0 after the decimal point, but also allow omitting, but do not allow separate decimal point. Your expression cannot satisfy a leading 0 omission. And, most importantly, "." Any character is represented in a regular expression, so for your expression, 2A2 can also pass the test.
^[-]?\d+[.]? \d*$

Should read as follows:
^[-]? (\d+\.?) \d*|\.\d+) $