Get double value from .Net TextBox in C++

Question

How can I get the double value from a textbox in .NET using C++. Do I have to get the text and do an atof() or is there an easier way?

Answer 1

Yes, you have to get the text and parse it - although you could stick within .NET and use Double.TryParse instead of atof(), which lets you detect user error more easily.

Convert.ToDouble and Double.Parse would both throw exceptions in the case of failure; atof() will silently ignore bad input from what I remember. Double.TryParse just returns true/false to indicate success/failure, and uses an out parameter to pass back the result of the parse. This is usually the right thing to do for user input - you want to be able to detect the failure, but exceptions aren't really appropriate as users entering invalid data is a far from exceptional situation.

Answer 2

In .NET you can use Double.Parse, Double.TryParse, or Convert.ToDouble.

Answer 3

You have to parse the text.

Double value = 0.0;

if (Double.TryParse(textBox.Text, out value))
{
    // Value is valid here.
}
else
{
   // Handle invalid input here.
}

Answer 4

it gives me an error when I try to use Double.TryParse, what do I need to include for this. sorry usually use linux.