如何防止C＃中输入无效导致崩溃？

我写的程序设置为只接受正整数作为输入。 如果用户输入了一个字母，那么它就会崩溃。 负整数不会导致任何问题，尽管它对我的程序如何运作并不“有效”。

我想做的是：

1. 防止程序从无效输入中崩溃。

2. 如果输入无效，则显示错误消息

3. 让程序从中断处继续，而不影响程序的其余部分。

此外，我的计划的一部分涉及分裂。 有没有办法阻止用户输入全零？

这是在C＃

我的代码：

using System; 

使用System.Collections.Generic; 使用System.Linq; 使用System.Text;

namespace OverallCalculator {

 class Program { static void Main(string[] args) { bool shouldContinue; do { Console.WriteLine("Enter Striking Level: "); string striking = Console.ReadLine(); Console.WriteLine("Enter Grappling Level: "); string grappling = Console.ReadLine(); Console.WriteLine("Enter Submission Level: "); string submission = Console.ReadLine(); Console.WriteLine("Enter Durability Level: "); string durability = Console.ReadLine(); Console.WriteLine("Enter Technical Level: "); string technical = Console.ReadLine(); Console.WriteLine("Enter Speed Level: "); string speed = Console.ReadLine(); Console.WriteLine("Enter Hardcore Level: "); string hardcore = Console.ReadLine(); Console.WriteLine("Enter Charisma Level: "); string charisma = Console.ReadLine(); int gra = Convert.ToInt32(grappling); int str = Convert.ToInt32(striking); int dur = Convert.ToInt32(durability); int spd = Convert.ToInt32(speed); int tec = Convert.ToInt32(technical); int hdc = Convert.ToInt32(hardcore); int cha = Convert.ToInt32(charisma); int sub = Convert.ToInt32(submission); int total = str + gra + sub + dur + tec + spd + cha + hdc; int overall = total / 8 + 8; Console.WriteLine("The Overall is " + overall); Console.WriteLine("Do you wish to continue? y/n? "); if (Console.ReadLine() == "y") { shouldContinue = true; } else break; } while (shouldContinue == true); } } 

}

Answer 1

干得好：

 using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace OverallCalculator { class Program { static void Main(string[] args) { bool shouldContinue = true; while (shouldContinue) { int strikingLevel = GetValue("Enter Striking Level: "); int grapplingLevel = GetValue("Enter Grappling Level: "); int submissionLevel = GetValue("Enter Submission Level: "); int durabilityLevel = GetValue("Enter Durability Level: "); int technicalLevel = GetValue("Enter Technical Level: "); int speedLevel = GetValue("Enter Speed Level: "); int hardcoreLevel = GetValue("Enter Hardcore Level: "); int charismaLevel = GetValue("Enter Charisma Level: "); int total = strikingLevel + grapplingLevel + durabilityLevel + submissionLevel + technicalLevel + speedLevel + charismaLevel + hardcoreLevel; int overall = total / 8 + 8; Console.WriteLine("\nThe Overall is {0}.", overall); while (true) { Console.WriteLine("Do you wish to continue? y/n? "); string response = Console.ReadLine(); if (response.Equals("y", StringComparison.CurrentCultureIgnoreCase) || response.Equals("yes", StringComparison.CurrentCultureIgnoreCase)) { shouldContinue = true; break; } else if (response.Equals("n", StringComparison.CurrentCultureIgnoreCase) || response.Equals("no", StringComparison.CurrentCultureIgnoreCase)) { shouldContinue = false; break; } } } } private static int GetValue(string prompt) { while (true) { Console.WriteLine(prompt); string input = Console.ReadLine(); int value; if (int.TryParse(input, out value)) { if (value <= 0) Console.WriteLine("Please enter a positive number."); else return value; } else { Console.WriteLine("Please enter a number."); } } } } } 

Answer 2

 int value = 0; if (!int.TryParse(input, out value)) { MessageBox.Show("Oops"); } else { // use the value in the variable "value". } 

Answer 3

 static void Main(string[] args) { bool validInput = false; string inputString; UInt32 validPositiveInteger = 0; while (!validInput) { Console.WriteLine("Please enter a positive 32 bit integer:"); inputString = Console.ReadLine(); if (!UInt32.TryParse(inputString, out validPositiveInteger)) { Console.WriteLine("Input was not a positive integer."); } else if (validPositiveInteger.Equals(0)) { Console.WriteLine("You cannot enter zero."); } else { validInput = true; //Or you could just break //break; } } Console.WriteLine(String.Format("Positive integer = {0}", validPositiveInteger)); } 

Answer 4

是的…在进行任何计算之前，您需要validation要使用的数据。 如果任何数据不正确，则会显示一个消息框，详细说明错误并将焦点返回到表单，以便用户可以修复错误。 根据需要重复。

Answer 5

当我第一次学习C＃时，我在很多个月前写过这个。 这是我在VB5天回来的VB函数的转换。 该函数的主要好处是没有错误 – 输入将不允许预定义列表之外的任何字符。

 /*********************************************************************** * bool ValiText(char inChar, * string valid, * bool editable, * bool casesensitive * Description: Validate Input Characters As They Are Input * Notes: For each control whose input you wish to validate, just put * e.Handled = ValiText(e.KeyChar, "0123456789/-" [,true][,true]) * In The KeyPress Event ***********************************************************************/ public bool ValiText(char inChar, string valid, bool editable, bool casesensitive) { string inVal = inChar.ToString(); string tst = valid; /// Editable - Add The Backspace Key if (editable) tst += ((char)8).ToString(); /// Case InSensitive - Make Them Both The Same Case if (!casesensitive) { tst = tst.ToLower(); inVal = inVal.ToLower(); } return tst.IndexOf(inVal,0,tst.Length) < 0; } public bool ValiText(char inChar, string valid, bool editable) { string tst = valid; /// Editable - Add The Backspace Key if (editable) tst += ((char)8).ToString(); return tst.IndexOf(inChar.ToString(),0,tst.Length) < 0; } public bool ValiText(char inChar, string valid) { return valid.IndexOf(inChar.ToString(),0,valid.Length) < 0; } 

请注意，这在Web APP上不起作用。