格式化文本框以在运行时以带小数的千位分隔符的形式显示用户输入

Question

i am still new to c#, i am trying to build a simple calculator with c# windows form. i did all the coding but i am stuck in formating my calculator screen(text box in this case) to display numbers with thousand separator comma and decimal point.

for example: if the user input 1000 i want it to display 1,000 of if the user input 1000.0123 i want it to display 1,000.0123 on the fly(just like the windows 10 calculator)

i really appreciate the any help, i have been searching all around the internet for some solution and came to nothing

Answer 1

use string format, in the textbox where you show the numbers:

txtNumber.text = string.Format("{0:n}",12521452.646521); // 12,521,452.64

or:

txtNumber.text = string.Format("{0:#,0.#########}", 12521452.646521))   // 12,521,452.646521

see more: C# String Format Method

Answer 2

var input = 1024.10;
Console.WriteLine(input.ToString("N"));

Output:

1,024.10

Format as a numeric value with 2 decimal places. For 3 or 4 decimal places you can use ToString("N3") or N4. For No decimal places ToString("N0")