.NET中Decimal.ToString()在不同电脑返回值不同，求原因

Let me break down why you're seeing this inconsistent output with your code:

decimal i = 5; 
return i.ToString();

On your machine it returns "5.0", but on another it returns "5" — this boils down to regional culture settings between the two systems.

Here's the full breakdown:

• When you call ToString() without parameters on a decimal, .NET uses the current thread's default CultureInfo to format the number. This pulls rules directly from your system's regional settings for how numeric values should be displayed.
• The key setting here is NumberDecimalDigits in the culture's NumberFormatInfo: it controls how many decimal places are shown by default. If one machine has this set to 1 (either via default regional settings or manual customization), it will append .0 to integer values. The machine returning "5" almost certainly has this set to 0.

To confirm this, you can run a quick test on both machines:

Console.WriteLine(System.Globalization.CultureInfo.CurrentCulture.NumberFormat.NumberDecimalDigits);

You’ll see the output matches your original discrepancy (1 vs 0).

For a consistent result across all machines, you have two solid options:

• Use the invariant culture to bypass regional formatting entirely:

  return i.ToString(System.Globalization.CultureInfo.InvariantCulture);
  

• Use a custom numeric format string to explicitly define your desired output (e.g., i.ToString("G") for the shortest possible representation, or i.ToString("#.0") to force one decimal place if needed).

内容的提问来源于stack exchange，提问作者Sadegh Alinejad