C++ Try Catch Block 不捕获异常答案

【问题标题】：C++ Try Catch Block does not catch an exceptionC++ Try Catch Block 不捕获异常
【发布时间】：2012-08-06 00:36:28
【问题描述】：

我是 C++ 的初学者，我正在尝试创建一个简单的控制台程序来计算线性方程的“m”和“b”...解析用户提供的输入双精度，我正在使用字符串流和使用 try-catch 块来检查错误输入。即使 catch 块有一个全局异常 [Unhandled exception at 0x74c8b9bc in Equation Solver.exe: Microsoft C++ exception: [rethrow] at memory location 0x00000000..]

double XOne;`enter code here`
double YOne;
double XTwo;
double YTwo;
bool inputCheck = false;
while (inputCheck == false)
{
    Clear();
    WriteLine("**Linear Equation**");
    Write("X1: ");
    string xone = ReadLine();
    Write("Y1: ");
    string yone = ReadLine();
    Write("X2: ");
    string xtwo = ReadLine();
    Write("Y2: ");
    string ytwo = ReadLine();
    try
    {
        stringstream s1(xone);
        if (s1 >> XOne) { s1 >> XOne; } else { throw; }
        stringstream s2(yone); // consider I give an invalid input for this variable
        if (s2 >> YOne) { s2 >> YOne; } else { throw; } // this doesn't solve the problem
        stringstream s3(xtwo);
        if (s3 >> XTwo) { s3 >> XTwo; } else { throw; }
        stringstream s4(ytwo);
        if (s4 >> YTwo) { s4 >> YTwo; } else { throw; }
    }
    catch (...) { WriteLine("Invalid Input"); ReadLine(); }
}

LinearEquation equation;
equation.Initialize(XOne, YOne, XTwo, YTwo);
stringstream s5;
s5 << equation.m;
string m = s5.str();
stringstream s6;
s6 << equation.b;
string b = s6.str();
Write("Y = ");
Write(m);
Write("X + ");
WriteLine(b);
ReadLine();

编辑第一个建议就像一个魅力......谢谢！这是我按照审稿人修改后的代码。

double XOne;
double YOne;
double XTwo;
double YTwo;
bool inputCheck = false;
while (inputCheck == false)
{
    Clear();
    WriteLine("**Linear Equation**");
    Write("X1: ");
    string xone = ReadLine();
    Write("Y1: ");
    string yone = ReadLine();
    Write("X2: ");
    string xtwo = ReadLine();
    Write("Y2: ");
    string ytwo = ReadLine();
    try
    {
        stringstream s1(xone);
        if (s1 >> XOne) { s1 >> XOne; } else { throw runtime_error("Invalid Input"); }
        stringstream s2(yone);
        if (s2 >> YOne) { s2 >> YOne; } else { throw runtime_error("Invalid Input"); }
        stringstream s3(xtwo);
        if (s3 >> XTwo) { s3 >> XTwo; } else { throw runtime_error("Invalid Input"); }
        stringstream s4(ytwo);
        if (s4 >> YTwo) { s4 >> YTwo; } else { throw runtime_error("Invalid Input"); }
    }
    catch (runtime_error e) { WriteLine(e.what()); ReadLine(); }
}

LinearEquation equation;
equation.Initialize(XOne, YOne, XTwo, YTwo);
stringstream s5;
s5 << equation.m;
string m = s5.str();
stringstream s6;
s6 << equation.b;
string b = s6.str();
Write("Y = ");
Write(m);
Write("X + ");
WriteLine(b);
ReadLine();

【问题讨论】：

标签： c++ exception error-handling try-catch

【解决方案1】：

throw 不带参数只能在处理异常时使用（即在 catch 块中或从 catch 块直接或间接调用的函数中），否则您必须使用带有参数的 throw通常是某种异常对象。

如果在未处理异常时执行throw std::terminate 将被调用以结束您的程序。

例如（在#include <stdexcept>之后）

throw std::runtime_error("Bad input");

【讨论】：