我正在尝试使用列表来存储和显示数据，从而在控制台应用程序中构建联系人管理器程序。我需要查看显示可用联系人摘要的报告，然后有一个菜单允许用户与该程序进行交互。我有一个方法来创建一个联系人和一个联系人对象。我还有一种更新联系人的方法，但我想让用户能够选择联系人的名字，姓氏，电子邮件地址，电话号码，类型，并能够使用用户输入的信息进行更新。但是在这一行Console.WriteLine（＆＃34; \ nUpdate联系人：{1}＆＃34;，contactList）;我一直收到错误：
未处理的类型＆＃39; System.FormatException＆＃39;发生了， 附加信息：索引（从零开始）必须大于或 等于零且小于参数列表的大小。
任何指导都将不胜感激。
static void Main(string[] args)
{
//Declare the list
List<Contact> contactList = new List<Contact>();
//Main Driver
char menuItem;
Console.WriteLine("Contact List\n");
menuItem = GetMenuItem();
while (menuItem != 'Q')
{
ProcessMenuItem(menuItem, contactList);
menuItem = GetMenuItem();
}
Console.WriteLine("\nThank you, goodbye");
Console.ReadLine();
}
//Returns either a 'C', 'R', 'U', 'D', 'L', or 'X' to the caller
static char GetMenuItem()
{
char menuItem;
DisplayMenu();
menuItem = char.ToUpper(IOConsole.GetChar("\nPlease pick an item: "));
while (menuItem != 'C'
&& menuItem != 'R' && menuItem != 'Q' && menuItem != 'U' && menuItem != 'D' && menuItem != 'S' && menuItem != 'L' && menuItem != 'F' && menuItem != 'P' && menuItem != 'T')
{
Console.WriteLine("\nError - Invalid menu item");
DisplayMenu();
menuItem = char.ToUpper(IOConsole.GetChar("\nEnter option or M for menu:"));
}
return menuItem;
}
static void DisplayMenu()
{
Console.WriteLine("C-> Create Contacts");
Console.WriteLine("R-> Remove Contacts");
Console.WriteLine("U-> Update Contacts");
Console.WriteLine("D -> Load data from file");
Console.WriteLine("S-> Save data to file");
Console.WriteLine("L-> View sorted by last name");
Console.WriteLine("F-> View sorted by first name");
Console.WriteLine("P-> View by partial name search");
Console.WriteLine("T-> View by contact type");
Console.WriteLine("Q-> Quit");
}
//Routes to the appropriate process routine based on the user menu choice
static void ProcessMenuItem(Char menuItem, List<Contact> contactList)
{
switch (menuItem)
{
case 'C':
createContact();
break;
case 'R':
Console.WriteLine("enter the contact name To delete");
removeContact(contactList, Console.Read().ToString() );
break;
case 'U':
updateContact(contactList);
break;
case 'D':
LoadFromFile();
break;
case 'S':
saveToFile();
break;
case 'L':
sortByLastName(contactList);
break;
case 'F':
sortByFirstName(contactList);
break;
case 'P':
DisplayList(contactList);
break;
case 'T':
sortByContactType();
break;
case 'Q':
break;
}
}
// allows the user to update a contact
public static void updateContact(List<Contact> contactList)
{
char answer, answer2, answer3, answer4,asnwer5;
String newFirstName = " ";
String newLastName = " ";
String newPhoneNumber = " ";
String newEmailAddress = " ";
//Type newContactType = Contact.ContactTypes;
Console.WriteLine("\nUpdate Contact:{1}" , contactList);
foreach (Contact obj in contactList)
{
answer = IOConsole.GetChar("\nEdit FirstName?: Y/N: ");
if (answer.Equals('Y') || answer.Equals('y'))
{
newFirstName = IOConsole.Getstring("\nUpdate Contact: please enter the contact's new first name: ");
obj.GetFirstName = newFirstName;
break;
}
else if (answer.Equals('N') || answer.Equals('n'))
{
}
answer2 = IOConsole.GetChar("\nEdit LastName?: Y/N: ");
if (answer2.Equals('Y') || answer.Equals('y'))
{
newLastName = IOConsole.Getstring("\nUpdate Contact: please enter the contact's new last name: ");
obj.GetFirstName = newLastName;
break;
}
else if (answer2.Equals('N') || answer.Equals('n'))
{
}
answer2 = IOConsole.GetChar("\nEdit EmailAddress?: Y/N: ");
if (answer2.Equals('Y') || answer.Equals('y'))
{
newEmailAddress = IOConsole.Getstring("\nUpdate Player: please enter the contact's new emailaddress) name: ");
obj.GetFirstName = newEmailAddress;
break;
}
else if (answer2.Equals('N') || answer.Equals('n'))
{
}
answer3 = IOConsole.GetChar("\nEdit phonenumber?: Y/N: ");
if (answer3.Equals('Y') || answer.Equals('y'))
{
newPhoneNumber = IOConsole.Getstring("\nUpdate Contact: please enter the contact's new phonenumber: ");
obj.GetFirstName = newPhoneNumber;
break;
}
else if (answer3.Equals('N') || answer.Equals('n'))
{
}
answer4 = IOConsole.GetChar("\nEdit ContactType?: Y/N: ");
/* if (answer4.Equals('Y') || answer.Equals('y'))
{
newContactType = IOConsole.Getstring("\nUpdate Player: please enter the contact's new type: ");
obj.GetFirstName = newContactType;
break;
}
else if (answer4.Equals('N') || answer.Equals('n'))
{
}*/
}
}
答案 0 :(得分：4)
你能改变一下吗？
Console.WriteLine("\nUpdate Contact:{1}" , contactList);
要：
Console.WriteLine("\nUpdate Contact:{0}" , contactList);
在格式化字符串时， 必须以0开头，按参数列表给出的顺序。