Use a regular expression to verify whether the input is a number

Use a regular expression to verify whether the input is a number

Sometimes the content entered in the text box must be data. How can we determine whether the content entered by the user is legal? Here I use a regular expression to achieve this effect, two lines of code (C #) done! Haha...

 

Static bool isnumeric (string Str)

{

System. Text. regularexpressions. RegEx reg1

= New system. Text. regularexpressions. RegEx (@ "^ [-]? (/D + /.? /D * |/./d +) $ ");

Return reg1.ismatch (STR );

}

The following events are used to call the above static method.

Private void button#click (Object sender, system. eventargs E)

{

If (! Isnumeric (this. textbox1.text. Trim ()))

{

MessageBox. Show ("the input content is invalid! ");

}

Else

{

MessageBox. Show ("the input data is valid! ");

}

}