Is .NET double.ToString threadsafe?
I'm seeing an issue in a production ASP.NET application that involves the following code, which is used to render the geocoordinates of a particular object:
private double _longitude;
private double _latitude;
public string ToCsvString()
{
return _latitude + "," + _longitude;
}
Thread.CurrentThread.CurrentCulture will be set to different values based on the incoming request. The behavior I'm seeing is that the result of this function will vary independent of the threadlocal culture. At times the decimal points and commas are incorrect for the current culture. More strangely, it seems that once set wrong, the wrong value persists.
Does ToString on double cache values?
It shouldn't cache the values, especially because of the culture issue you mentioned. Two things come to mind:
为什么不使用显式的ToString方法来让你手动指定一个区域性的IFormatProvider？
For rendering geocoordinates, I suggest that you best define your own fixed formatting or culture rather than leaving it for the framework, default culture setting or culture info of the running thread.
I would do it like this to format it to 4 decimal points:
return _latitude.ToString("0.0000") + "," + _longitude.ToString("0.0000");
or
string.Format("{0:0.0000}, "{1:0.0000}", _latitude, _longitude);
Or if you want the decimal separator to be culture specific,
CultureInfo ci = System.Globalization.CultureInfo.GetCultureInfo("en-AU");
return _latitude.ToString("N4", ci) + "," + _longitude.ToString("N4", ci);