请帮助..创建默认和最大数量 [英] Please Help.. Creating a default and maximum number

问题描述

我的程序现在正在运行并正确编译，但我仍然遇到设置最大和默认安装的问题。



我真的很感激一些指示。我是C＃的新手，所以非常感谢任何帮助！



一些指导原则：'H'最多可以安装5个。默认值为1.

'E'默认包含10个安装。对于10以上的每个安装，都会添加额外的价格。

'H'和'E'都有默认的附加程序0.数字不能是负数。



这是我的到目前为止的代码：

I have my program working and compiling correctly now, but I am still having an issue getting the maximum and default installations set.

I would really appreciate some pointers. I'm new to C#, so any help is greatly appreciated!

A few guidelines: 'H' can have a maximum of 5 installations. The default is 1.
'E' has a default of 10 installations included. For each installation above 10, the additional price is added.
Both 'H' and 'E' have a default of additional programs of 0. Number must not be negative.

Here is my code thus far:

private void btnCalculate_Click(object sender, EventArgs e)
   {
       const decimal U_CUST = 999;
       const decimal E_CUST = 249;
       const decimal ADD_E_CUST = 99;
       const decimal H_CUST = 99;
       const decimal ADD_H_CUST = 49;

       char CustType;
       int AdditionalPrograms = 0;
       int Installations = 10;
       decimal Bill = 0;

       if (txtCustType.Text.Length != 1)
       {
           MessageBox.Show("Customer type is required.", Text, MessageBoxButtons.OK, MessageBoxIcon.Information);
           txtCustType.Focus();
           return;
       }

       CustType = char.Parse(txtCustType.Text);
       CustType = char.ToUpper(CustType);
       txtCustType.Text = CustType.ToString();

       if (CustType != 'U' && CustType != 'H' && CustType != 'E')
       {
           MessageBox.Show("Invalid customer type - must be H, E or U.", Text, MessageBoxButtons.OK, MessageBoxIcon.Information);
           txtCustType.Focus();
           return;
       }

       //calculate bill according to customer type
       if (CustType == 'U')
       {
           Bill = U_CUST;
       }
       else
       {
           if (txtAddPrograms.Text != "") // AdditionalPrograms will remain at 0 if textbox is empty
           {
               bool isValid = int.TryParse(txtAddPrograms.Text, out AdditionalPrograms);
               if (!isValid || AdditionalPrograms < 0)
               {
                   MessageBox.Show("Invalid number of additional programs - can't be negative.", Text, MessageBoxButtons.OK, MessageBoxIcon.Information);
                   txtAddPrograms.Focus();
                   return;
               }
           }

           if (CustType == 'H')
           {
               Bill = H_CUST + ADD_H_CUST * AdditionalPrograms;
           }
           else  // Customer Type must be 'E'
           {
               if (txtInstallations.Text != "") // Installations will remain at 10 if textbox is empty
               {
                   bool isValid = int.TryParse(txtInstallations.Text, out Installations);
                   if (!isValid || Installations < 1)
                   {
                       MessageBox.Show("Invalid number of installations - must be positive.", Text, MessageBoxButtons.OK, MessageBoxIcon.Information);
                       txtInstallations.Focus();
                       return;
                   }
               }

               Bill = E_CUST + ADD_E_CUST * AdditionalPrograms;
               if (Installations > 10) Bill *= 1 + (Installations - 10) * 0.1m;
           }
       }

       //Display the result.
       lblBill.Text = Bill.ToString("C");
       if (CustType == 'E' && Installations > 40)
       {
           MessageBox.Show("Note that the unlimited plan would be more economic.", Text, MessageBoxButtons.OK, MessageBoxIcon.Information);
       }
   }

推荐答案

好的 - 让我们再看看这个...



那里有一些奇怪的代码 - 我认为你不知道字符串可以被处理作为 char 的数组？所以你可以替换它：

OK - let's have another look at this...

There is some rather odd code there - I take it you don't know that a string can be treated as an array of chars? So you could replace this:

CustType = char.Parse(txtCustType.Text);
CustType = char.ToUpper(CustType);
txtCustType.Text = CustType.ToString();

这个：

With this:

txtCustType.Text = txtCustType.Text.ToUpper();
CustType = txtCustType.Text[0];

哪个更明显一点。



但是......我个人也不会乱用角色 - 使用直接改为字符串！ ：笑：



其次，你似乎花了相当多的时间来转换数字并检查它们是否正面 - 你是否仅限于使用TextBoxes？因为如果你不是，那么有一个名为NumericUpDown的方便控件 - 它只能在一定范围内保存有效数字，并且不需要检查或转换，因为它提供十进制直接值。这可以清理你的代码！

Which is a little more obvious.

But...personally I wouldn't mess about with characters anyway - use the strings directly instead! :laugh:

Secondly, you seem to spend a fair amount of time converting numbers and checking they are positive - are you restricted to using TextBoxes? Because if you aren't, then there is a handy control called a NumericUpDown - which can only ever hold valid numbers in a certain range, and needs no checking or conversion as it provides a decimal value directly. This could clean your code up lots!

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