我正在尝试使用Visual Studio编写一个C＃程序，该程序从文件中读取数据并允许我对数据执行各种排序。我是初学者，所以花了很多研究来弄清楚如何编写这段代码：现在我得到了一个：
格式异常未处理。输入字符串不正确 格式
我不确定我哪里出错了。这发生在以下代码行中：
Candidate newrec = new Candidate(str[0], str[1], str [2], str[3], str[4], str[5], str[6], Convert.ToInt32(str[7]), str[8], str[9], str[10], str[11]);
整个代码如下：
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.IO;
using System.Collections;
namespace Unit4IP
{
//used to sort in asceding and descending order
public struct Candidate:IComparable
{
public char[] _FirstName;
public char[] _LastName;
public char[] _Company;
public char[] _Address;
public char[] _City;
public char[] _Country;
public char[] _State;
public char[] _Phone;
public char[] _Fax;
public char[] _Email;
public char[] _Web;
public int _zip;
//for comparing objects
public int CompareTo(object obj)
{
Candidate Candidate2 = (Candidate)obj;
return _LastName.ToString().CompareTo(Candidate2._LastName.ToString());
}
//implements sorting based on assignments such as zip, lastname, etc.
public int CompareTo(Candidate Candidate2,
CandidateComparer.ComparisonType comptype)
{
if(comptype==CandidateComparer.ComparisonType.Lastname)
{
String _LName = new String(_LastName);
String LName = new String(Candidate2._LastName);
return _LName.CompareTo(LName);// Convert Character Array to String because CompareTo Works efficiently with Strings
}
else
{
return Candidate2._zip.CompareTo(_zip); // compareto values that are interchanged in descending order
}
}
//Constructor of Candidate Structure
public Candidate(string FirstName, string LastName, string Company, string Address, string City, string Country, string State, int zip, string Phone, string Fax, string Email, string Web)
{
_FirstName = new char[12];
_LastName = new char[16];
_Company = new char[32];
_Address = new char[32];
_City = new char[24];
_Country = new char[24];
_State = new char[2];
_Phone = new char[12];
_Fax = new char[12];
_Email = new char[32];
_Web = new char[42];
_FirstName = FirstName.ToCharArray();
_LastName = LastName.ToCharArray();
_Company = Company.ToCharArray();
_Address = Address.ToCharArray();
_City = City.ToCharArray();
_Country = Country.ToCharArray();
_State = State.ToCharArray();
_zip = zip;
_Phone = Phone.ToCharArray();
_Fax = Fax.ToCharArray();
_Email = Email.ToCharArray();
_Web = Web.ToCharArray();
}
//Implement IComparer Interface as nested structure
public struct CandidateComparer : IComparer
{
public enum ComparisonType
{ Lastname = 1, zip = 2 }
private ComparisonType _comparisonType;
public ComparisonType comptype
{
get { return _comparisonType; }
set { _comparisonType = value; }
}
public int Compare(object x, object y)
{
Candidate Candidate1 = (Candidate)x;
Candidate Candidate2 = (Candidate)y;
return Candidate1.CompareTo(Candidate2, _comparisonType);
}
}
}
class Program
{
static void Main(string[] args)
{
ArrayList ArrayTest = new ArrayList();
//Loading of File 'ITCO321_U4_sample_data.csv' into ArraList. File only holds values, no heading i.e. remove headings
StreamReader stream1 = File.OpenText("c:\\Users\\Cdhss\\Documents\\ITCO321_U4IP_sample_data-2.csv");
string recdata = null;
while ((recdata = stream1.ReadLine()) != null)
{
string[] str = recdata.Split(',');
Candidate newrec = new Candidate(str[0], str[1], str [2], str[3], str[4], str[5], str[6], Convert.ToInt32(str[7]), str[8], str[9], str[10], str[11]);
ArrayTest.Add(newrec);//add struct object into ArrayList
}
//Traversing of Records
Console.WriteLine("Traversing Records");
foreach (Candidate Candidate1 in ArrayTest)
{
string fname = new String(Candidate1._FirstName);
string lname=new String(Candidate1._LastName);
string company = new String(Candidate1._Company);
string address=new String(Candidate1._Address);
string city=new String(Candidate1._City);
string country = new String(Candidate1._Country);
string phone = new String(Candidate1._Phone);
string fax = new String(Candidate1._Fax);
string email=new String(Candidate1._Email);
string web = new String(Candidate1._Web);
Console.WriteLine( fname + "," + lname + "," + company + "," + address + "," + city + "," + country + "," + Candidate1._zip + "," + phone + "," + fax + "," + email + "," + web);
}
Candidate.CandidateComparer comparer = new Candidate.CandidateComparer();
//Sort by Lastname in ascending order
comparer.comptype = Candidate.CandidateComparer.ComparisonType.Lastname;
ArrayTest.Sort(comparer);
Console.WriteLine("Sorting of Elements by LastName");
foreach (Candidate Candidate1 in ArrayTest)
{
string fname = new String(Candidate1._FirstName);
string lname = new String(Candidate1._LastName);
string company = new String(Candidate1._Company);
Console.WriteLine("\t" + fname + "," + lname + "," + company);
}
// Data sorted in desending order of ZIP field
comparer.comptype = Candidate.CandidateComparer.ComparisonType.zip;
ArrayTest.Sort(comparer);
Console.WriteLine("Sorting of Elements by Zip");
foreach (Candidate Candidate1 in ArrayTest)
{
string fname = new String(Candidate1._FirstName);
string lname = new String(Candidate1._LastName);
string company = new String(Candidate1._Company);
Console.WriteLine("\t" + fname + "," + lname + "," + company + "," + Candidate1._zip);
}
//Display Records of 'NY' State
Console.WriteLine("Display Records of NY State");
foreach (Candidate Candidate1 in ArrayTest)
{
string fname = new String(Candidate1._FirstName);
string lname = new String(Candidate1._LastName);
string company = new String(Candidate1._Company);
string address = new String(Candidate1._Address);
string city = new String(Candidate1._City);
string country = new String(Candidate1._Country);
string phone = new String(Candidate1._Phone);
string fax = new String(Candidate1._Fax);
string email = new String(Candidate1._Email);
string web = new String(Candidate1._Web);
if (new String(Candidate1._State).Contains("NY"))
Console.WriteLine(fname + "," + lname + "," + company + "," + address + "," + city + "," + country + "," + Candidate1._zip + "," + phone + "," + fax + "," + email + "," + web);
}
Console.Read();
}
}
}
答案 0 :(得分：0)
您的问题出在您对Convert.ToInt32的调用中。无论你传递的是什么字符串都不能被解析为int。
这里一个好的解决方案可能是使用一些结构化的异常处理，使用try catch块或Int32.TryParse（string），例如你可以这样做
int intValue;
if (Int32.TryParse(str[7], out intValue))
{
//Do some thing with the int value
}
else
{
throw new Exception("Some informative error message, probably using string.Format to include the string you tried to parse");
}
如果解析成功，则TryParse返回true，否则返回false，并将解析后的整数值放入第二个out参数。
关于您的代码的一些其他评论可以帮助您。