I am trying to check if a string contains a numeric value, if it doesnt return to a label if it does then I would like to show the main window. How can this be done?
If (mystring = a numeric value)
//do this:
var newWindow = new MainWindow();
newWindow.Show();
If (mystring = non numeric)
//display mystring in a label
label1.Text = mystring;
else return error to message box
use TryParse.
double val;
if (double.TryParse(mystring, out val)) {
..
} else {
..
}
This will work for strings that translate directly to a number. If you need to worry about stuff like $ and , also, then you'll need to do a little more work to clean it up first.
Int32 intValue;
if (Int32.TryParse(mystring, out intValue)){
// mystring is an integer
}
Or, if it's a decimal number:
Double dblValue;
if (Double.TryParse(mystring, out dblValue)){
// mystring has a decimal number
}
Some examples, BTW, can be found here.
Testing foo:
Testing 123:
It's an integer! (123)
It's a decimal! (123.00)
Testing 1.23:
It's a decimal! (1.23)
Testing $1.23:
It's a decimal! (1.23)
Testing 1,234:
It's a decimal! (1234.00)
Testing 1,234.56:
It's a decimal! (1234.56)
A couple more I've tested:
Testing $ 1,234: // Note that the space makes it fail
Testing $1,234:
It's a decimal! (1234.00)
Testing $1,234.56:
It's a decimal! (1234.56)
Testing -1,234:
It's a decimal! (-1234.00)
Testing -123:
It's an integer! (-123)
It's a decimal! (-123.00)
Testing $-1,234: // negative currency also fails
Testing $-1,234.56:
Double.TryParse can handle commas in a number but Int32.TryParse cannot.
double.TryParse as an integer is also a valid double. If you require that the number also be an integer, then use int.TryParsedouble value;
if (double.tryParse(mystring, out value))
{
var newWindow = new MainWindow();
newWindow.Show();
}
else
{
label1.Text = mystring;
}
You could simply reference Microsoft.VisualBasic.dll, then do the following:
if (Microsoft.VisualBasic.Information.IsNumeric(mystring))
{
var newWindow = new MainWindow();
newWindow.Show();
}
else
{
label1.Text = mystring;
}
The VB one actually performs better, as it doesn't throw an exception for every failed conversion.
VB to check if a string is numeric or not. there are so many other ways X.tryParse, Regex, LINQ, foreach some are better than the others, ** but there is just no need to use C# little brother - VB.** for this task(or should I say for tasks.)You may use a boolean to judge if the string contains numeric chars.
public bool GetNumberFromStr(string str)
{
string ss = "";
foreach (char s in str)
{
int a = 0;
if (int.TryParse(Convert.ToString(s), out a))
ss += a;
}
if ss.Length >0
return true;
else
return false;
}
Try taking the Label's caption into a string and
use Int.TryParse() method to decide whether text is integer or string. the method will return true if yes , else it will return false. Code will be like :
if (Int.TryParse(<string> , out Num) == True)
{
// is numeric
}
else
{
//is string
}
where Num will contain your integer value if conversion is a success
A good example of method that will do this can be found at: http://msdn.microsoft.com/en-us/library/f02979c7.aspx
There's even some code doing something almost exactly what you want. You can use a Int32.TryParse(string) if you're expecting integer values. If you anticipate doubles, use Double.TryParse(string).
