How to keep zero decimal place for zero?

Question

I used:

Result_TextBox.Text = result.ToString(".#######");  //result is double

But if the result is 100.0000000, it becomes 100. What should I use in order to keep the accuracy of 7 decimals place?

I tried:

Result_TextBox.Text = Math.round(result, 7);  //but this is effective at all, why?

Please help

Update: can someone explain "#" and "0"?

Answer 1

Use:

Result_TextBox.Text = result.ToString("0.0000000");

The second line doesn't work because you're trying to assign a numeric data type to a string without conversion.

Answer 2

这有效

Result_TextBox.Text = result.ToString("#.0000000");

Answer 3

尝试：

result.ToString("0.0000000")

Answer 4

There is a Standard numeric format strings for that.
You can use The Fixed-Point ("F") Format Specifier followed by a number to define the number of decimal digits.

Console.WriteLine(100.ToString("F7"));
// -> 100.0000000

Console.WriteLine(100.ToString("F3"));
// -> 100.000