String.Format中数字的动态长度 [英] Dynamic length of a number in a String.Format

问题描述

大家好

我有一段代码来创建具有4个变量的文档编号.

前缀，后缀，NextNum和长度.

前三个很简单.在过去的第四版中，我已经进行了硬编码，但现在需要改进.一个答案是使用switch语句使用用户可能选择的几个选项之一，但这似乎是不好的编码.

代码:

Hi All

I have a piece of code to create document numbers featuring, 4 variables.

Prefix, Suffix, NextNum and Length.

The first 3 are rather simple. In the past the 4th one I have hard coded but now it needs improvement. One answer is to use a switch statement to use one of a few options the user may have selected but that seems like bad coding.

Code:

list = fa.SelectList("select Prefix, Suffix, NextNum, Length from docnumbers where Form = 'Invoice' limit 1", list);

t0.Text = String.Format("{0}{2:000000}{1}", list[0][0], list[1][0], Convert.ToInt32(list[2][0]), list[3][0]);

我已经硬编码必须显示6个字符，但是现在我希望它从数据库中的Length变量中获取.

有什么想法吗?

非常感谢
安德鲁

开关看起来像

I have hardcoded that 6 characters must be displayed but now I want it to get it from the Length variable in the database.

Any ideas?

Many thanks
Andrew

Switch would look like

list = fa.SelectList("select Prefix, Suffix, NextNum, Length from docnumbers where Form = 'Invoice' limit 1", list);

switch (list[3][0])
            {
                case 1:
                    t0.Text = String.Format("{0}{2:0}{1}", list[0][0], list[1][0], Convert.ToInt32(list[2][0]));
                    break;
                case 2:
                    t0.Text = String.Format("{0}{2:00}{1}", list[0][0], list[1][0], Convert.ToInt32(list[2][0]));
                    break;
                case 3:
                    t0.Text = String.Format("{0}{2:000}{1}", list[0][0], list[1][0], Convert.ToInt32(list[2][0]));
                    break;
                case 4:
                    t0.Text = String.Format("{0}{2:0000}{1}", list[0][0], list[1][0], Convert.ToInt32(list[2][0]));
                    break;
                case 5:
                    t0.Text = String.Format("{0}{2:00000}{1}", list[0][0], list[1][0], Convert.ToInt32(list[2][0]));
                    break;
                case 6:
                    t0.Text = String.Format("{0}{2:000000}{1}", list[0][0], list[1][0], Convert.ToInt32(list[2][0]));
                    break;
                case 7:
                    t0.Text = String.Format("{0}{2:0000000}{1}", list[0][0], list[1][0], Convert.ToInt32(list[2][0]));
                    break;
                case 8:
                    t0.Text = String.Format("{0}{2:00000000}{1}", list[0][0], list[1][0], Convert.ToInt32(list[2][0]));
                    break;
                case 9:
                    t0.Text = String.Format("{0}{2:000000000}{1}", list[0][0], list[1][0], Convert.ToInt32(list[2][0]));
                    break;
                case 10:
                    t0.Text = String.Format("{0}{2:0000000000}{1}", list[0][0], list[1][0], Convert.ToInt32(list[2][0]));
                    break;
                default:
                    t0.Text = String.Format("{0}{2}{1}", list[0][0], list[1][0], Convert.ToInt32(list[2][0]));
                    break;
            }

推荐答案

您可以创建一个字符串变量并使用它:

You could create a string variable and use it:

string zeroes = new string(''0'', (list[3][0]));
string testFormat = "{0}{2:" + zeroes + "}{1}";
tx0.Text = String.Format(testFormat, list[0][0], list[1][0], Convert.ToInt32(list[2][0]));

这篇关于String.Format中数字的动态长度的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！