Parse strings to double with comma and point

You want to treat dot (.) like comma (,). So, replace

if (double.TryParse(values[i, j], out tmp))

with

if (double.TryParse(values[i, j].Replace('.', ','), out tmp))

To treat both , and . as decimal point you must not only replace one with the other, but also make sure the Culture used parsing interprets it as a decimal point.

text = text.Replace(',', '.');
return double.TryParse(text, NumberStyles.Any, CultureInfo.InvariantCulture, out value);

You DO NOT NEED to replace the comma and dot..

I have had the very same problem. The reason is simple, the conversion culture plays a big role in which the comma or a dot is interpreted. I use a German culture where the comma distinguish the fractions, where as elsewhere the dot does the job.

Here I made a complete example to make the difference clear.

string[] doubleStrings = {"hello", "0.123", "0,123"};
double localCultreResult;
foreach (var doubleString in doubleStrings)
{
    double.TryParse(doubleString, NumberStyles.Any, CultureInfo.CurrentCulture, out localCultreResult);
    Console.WriteLine(string.Format("Local culture results for the parsing of {0} is {1}", doubleString, localCultreResult));
}

double invariantCultureResult;
foreach (var doubleString in doubleStrings)
{
    double.TryParse(doubleString, NumberStyles.Any, CultureInfo.InvariantCulture, out invariantCultureResult);
    Console.WriteLine(string.Format("Invariant culture results for the parsing of {0} is {1}", doubleString, invariantCultureResult));
}

The results is the following:

Play around with the culture and you will get the result you need.