C sharp systemformatexpection [英] C sharp systemformatexpection
本文介绍了C sharp systemformatexpection的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
你好
我正在做一个C sharp控制台应用程序，但我有一个问题。这是警告信息和标记的行
Hello
Im doing an C sharp console application, but im having an issue. Here is the warning message and the line that is marked
<br />
An unhandled exception of type 'System.FormatException' occurred in mscorlib.dll<br />
<br />
line =Convert.ToInt32(temp);
这里是完整的代码
here is the full code
using System.Collections.Generic;
using System;
using System.Diagnostics;
using System.Data;
using System.Xml.Linq;
using Microsoft.VisualBasic;
using System.Collections;
using System.Linq;
using Microsoft.VisualBasic.CompilerServices;
namespace Assignment1
{
sealed class Module1
{
static string temp; //Global variable
static public void Main()
{
int price = 0;
int paid = 0;
int balance = 0;
int no_of_500 = 0;
int no_of_100 = 0;
int no_of_50 = 0;
int no_of_20 = 0;
int no_of_10 = 0;
int no_of_5 = 0;
int no_of_1 = 0;
Console.WriteLine();
Console.Write("Enter the price = ");
//let user to enter and assigning it to variable by explicitly casing to int since option "strict on" is activated
price = validateInput();
Console.WriteLine();
Console.Write("Paid = ");
paid = validateInput();
//check paid cash is not less than the price
if (paid < price)
{
Console.WriteLine();
Console.WriteLine("Amount you paid is not sufficient.You need to pay more " + (price - paid).ToString() + " kr.");
Console.WriteLine();
//show balance
}
else
{
balance = paid - price;
Console.WriteLine();
Console.Write("Balance = " + balance.ToString());
Console.WriteLine();
Console.WriteLine();
//check for how many 500 notes
//if balance is greater than 500
//then using "\" divition find how many 500 s inside the balance
//finally update the balance by subtracting toatal value of 500 notes
//same logic will apply for all notes and coins in the order of 500,100,50,20,10,5,1
if (balance >= 500)
{
no_of_500 = balance / 500;
balance = balance - no_of_500 * 500;
}
if (balance >= 100)
{
no_of_100 = balance / 100;
balance = balance - no_of_100 * 100;
}
if (balance >= 50)
{
no_of_50 = balance / 50;
balance = balance - no_of_50 * 50;
}
if (balance >= 20)
{
no_of_20 = balance / 20;
balance = balance - no_of_20 * 20;
}
if (balance >= 10)
{
no_of_10 = balance / 10;
balance = balance - no_of_10 * 10;
}
if (balance >= 5)
{
no_of_5 = balance / 5;
balance = balance - no_of_5 * 5;
}
//at last the remainig balance less than five means there will be equal no of 1 crown coins
if (balance <= 4)
{
no_of_1 = balance;
}
//show how many notes and coins to change back
if (no_of_500 > 0)
{
Console.WriteLine(no_of_500.ToString() + " x 500 sek note");
}
if (no_of_100 > 0)
{
Console.WriteLine(no_of_100.ToString() + " x 100 sek note");
}
if (no_of_50 > 0)
{
Console.WriteLine(no_of_50.ToString() + " x 50 sek note");
}
if (no_of_20 > 0)
{
Console.WriteLine(no_of_20.ToString() + " x 20 sek note");
}
if (no_of_10 > 0)
{
Console.WriteLine(no_of_10.ToString() + " x 10 kr");
}
if (no_of_5 > 0)
{
Console.WriteLine(no_of_5.ToString() + " x 5 kr");
}
if (no_of_1 > 0)
{
Console.WriteLine(no_of_1.ToString() + " x 1 kr");
}
}
//wait for key press to stop sudden closing
Console.ReadLine();
}
private static int validateInput()
{
int value = default(int);
try
{
//take no of items to string num
temp = Console.ReadLine();
//if input is not numeric this will throw an InvalidCastException when it tries to cast to integer and
//will jump to catch block
value =Convert.ToInt32(temp);
//check whether is it has decimal places by checking for (".")
//if input is like 12.5 it will split in to two parts as 12 and 5 by "."
//and length of parts() will be two. that means entered value is not a whole number
string[] parts = temp.Split('.');
if (parts.Length == 2)
{
Console.WriteLine();
Console.WriteLine(" Input must be an Non negative / whole / numeric value.");
Console.ReadLine();
ProjectData.EndApp();
}
else
{
// if it is not charcter and not fractional then cast it to integer
value = int.Parse(temp);
}
//if number is negative
if (value < 0)
{
Console.WriteLine();
Console.WriteLine(" Input must be an Non negative / whole / numeric value.");
Console.ReadLine();
ProjectData.EndApp();
}
}
catch (InvalidCastException)
{
Console.WriteLine();
Console.WriteLine(" Input must be an Non negative / whole / numeric value.");
Console.ReadLine();
ProjectData.EndApp();
}
return value;
}
}
}
推荐答案
使用 Int32.TryParse [ ^ ]而不是直接演员。
Use Int32.TryParse[^] instead of a direct cast.
这篇关于C sharp systemformatexpection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！
查看全文
