IndexOutOfRangeException？

Question

在下面的代码中，我正在接收和超出范围异常。

private void btnRoll_Click(object sender, EventArgs e)
    {
        int success4 = 0;
        int success6 = 0;
        int success8 = 0;
        int success10 = 0;
        int success20 = 0;
        int botch4 = 0;
        int botch6 = 0;
        int botch8 = 0;
        int botch10 = 0;
        int botch20 = 0;

        if (cbnd4.SelectedIndex != 0)
        {

            int value = 4;
            int arraySize = (int)cbnd4.SelectedIndex;
            int[] refArray = randomNumber(value, arraySize);
            foreach (int i in refArray)
            {

                if (cbGame.SelectedIndex == 1)
                {
                    if (refArray[i] >= 2)
                    {
                        success4++;
                    }
                    if (refArray[i] == 1)
                    {
                        botch4++;
                    }
                }
                if (cbGame.SelectedIndex == 2)
                {
                    if(refArray[i] >= 2)
                    {
                        success4++;
                    }
                    if (refArray[i] == 1)
                    {
                        botch4++;
                    }
                }


            }
        }
           /* if (cbmd4.SelectedIndex != 0)
            {
            }
            */
         if (cbnd6.SelectedIndex != 0)
        {
            int value = 6;
            int arrySize = (int)cbnd6.SelectedIndex;
            int[] refArray = randomNumber(value, arrySize);
            foreach (int i in refArray)
            {


                if (cbGame.SelectedIndex == 1)
                {
                    if (refArray[i] >= 4)
                    {
                        success6++;
                    } if (refArray[i] == 1)
                    {
                        botch6++;
                    }
                }
                if (cbGame.SelectedIndex == 2)
                {
                    if (refArray[i] >= 4)
                    {
                        success6++;
                    }
                    if (refArray[i] == 1)
                    {
                        botch6++;
                    }
                }


            }
        }
        if (cbnd8.SelectedIndex != 0)
        {
            int value = 8;
            int arrySize = (int)cbnd8.SelectedIndex;
            int[] refArray = randomNumber(value, arrySize);
            foreach (int i in refArray)
            {

                if (cbGame.SelectedIndex == 1)
                {
                    if (refArray[i] >= 5)
                    {
                        success4++;
                    }
                    if (refArray[i] == 1)
                    {
                        botch8++;
                    }
                }
                if (cbGame.SelectedIndex == 2)
                {
                    if (refArray[i] >= 5)
                    {
                        success4++;
                    }
                    if (refArray[i] == 1)
                    {
                        botch8++;
                    }
                }


            }
        }
        if (cbnd10.SelectedIndex != 0)
        {
            int value = 10;
            int arrySize = (int)cbnd10.SelectedIndex;
            int[] refArray = randomNumber(value, arrySize);
            foreach (int i in refArray)
            {

                if (cbGame.SelectedIndex == 1)
                {
                    if (refArray[i] >= 7)
                    {
                        success10++;
                    }
                    if (refArray[i] == 1)
                    {
                        botch10++;
                    }
                }
                if (cbGame.SelectedIndex == 2)
                {
                    if (refArray[i] >= 7)
                    {
                        success10++;
                    }
                    if (refArray[i] == 1)
                    {
                        botch10++;
                    }
                }


            }
        }
        if (cbnd20.SelectedIndex != 0)
        {
            int value = 20;
            int arrySize = (int)cbnd20.SelectedIndex;
            int[] refArray = randomNumber(value, arrySize);
            foreach (int i in refArray)
            {

                if (cbGame.SelectedIndex == 1)
                {
                    if (refArray[i] >= 16)
                    {
                        success20++;
                    }
                    if (refArray[i] == 1)
                    {
                    botch20++;
                    }
                }
                if (cbGame.SelectedIndex == 2)
                {
                    if (refArray[i] >= 7)
                    {
                        success20++;
                    }
                    if (refArray[i] == 1)
                    {
                        botch20++;
                    }
                }


            }
        }
        lBotch_Result.Text = Convert.ToString(botch4 + botch6 + botch8 + botch10 + botch20);
        lSuccess_Result.Text = Convert.ToString(success4 + success6 + success8 + success10 + success20);
        MessageBox.Show("d4 successes: " +
            success4.ToString() +
            "\r\nd6 Successes: " +
            success6.ToString() +
            "\r\nd8 Successes: " +
            success8.ToString() +
            "\r\nd10 Successes: " +
            success10.ToString() +
            "\r\nd20 Successes: " +
            success20.ToString() +
            "\r\nd4 Botches: " +
            botch4.ToString() +
            "\r\nd6 Botches: " +
            botch6.ToString() +
            "\r\nd8 Botches: " +
            botch8.ToString() +
            "\r\nd10 Botches: " +
            botch10.ToString() +
            "\r\nd20 Botches: " +
            botch20.ToString());

}

当if(refArrayi >= 7)和refArray.Length包含一个奇数int值时，就会出现超出范围的异常。

下面是异常输出：

System.IndexOutOfRangeException未被处理

Message="IndexOutOfRangeException“

Table_Top_Game_Dice.Form1.btnRoll_Click(Object StackTrace:在System.Windows.Forms.Control._InternalWnProc(WM wm，Int32 wParam，EventArgs e) at System.Windows.Forms.Button.OnClick(EventArgs e) at System.Windows.Forms.ButtonBase.WnProc(WM wm，Int32 wParam，Int32 lParam)Int32 lParam) at Microsoft.AGL.Forms.EVL.EnterMainLoop(IntPtr hwnMain) at System.Windows.Forms.Application.Run(Form fm) at Table_Top_Game_Dice.Program.Main()

这里的任何建议都将不胜感激。为了解决这个问题，我已经用头撞墙5个小时了。

哦，refArray从以下函数获得它的值：(如果有帮助的话)

private int[] randomNumber(int value, int arraySize)
    {
        int[] randArray = new int[arraySize];
        maxValue = value;
        Random rand = new Random();
        for (int i = 0; i < arraySize; i++)
        {
           randArray[i] = rand.Next(minValue, maxValue);
        }
        return randArray;
    }

Answer 1

显然，您正在尝试访问数组结束后的数组元素。

randomNumber()方法生成一个随机数数组，其中数组的大小和最大值是独立的。因此，如果与{ 1, 7, 13 } 3和value 20一起调用，则可能返回value。

然后使用foreach (int i in refArray)迭代数组。因此，将有三个迭代，将i设置为1，然后是7，最后是13。

因此，如果使用refArray[i]访问数组，则尝试访问数组元素和索引1、7和13，因此在第二次迭代中获得一个IndexOutOfRangeException，因为您试图在索引7处访问元素，而数组只包含3个元素。

您是否打算使用for (int i = 0; i < refArray.Length; i++)而不是foreach循环？

Answer 2

我没有发现错误，但是您正在重复大量的代码。尝试将所有这些代码封装在函数中的每个"if (cbndXX.SelectedIndex != YY)“中。

就像这样：

private void RefactorizedFunction(ComboBox cmb, ComboBox cbGame, ref int success, ref int botch, int value, int maxsuxcess)
{
    var arraySize = (int)cmb.SelectedIndex;
    int[] refArray = randomNumber(value, arraySize);

    foreach (int i in refArray)    //WARNING HERE...
    {

                if (cbGame.SelectedIndex == 1)
                {
                    if (refArray[i] >= maxsuxcess)
                    {
                        success++;
                    }
                    if (refArray[i] == 1)
                    {
                        botch++;
                    }
                }
                if (cbGame.SelectedIndex != 2) continue;
                if (refArray[i] >= maxsuxcess)
                {
                    success++;
                }
                if (refArray[i] == 1)
                {
                    botch++;
                }
            }
    }

它没有经过测试，也不会解决您的问题，但我相信您的代码将更易于调试。还有其他改进代码的方法，比如使用字典或数组来代替所有这些successXX和botchXX vars，但是.循序渐进。

Answer 3

这段代码难道不能生成一个等于数组大小的int，然后在i从数组中读取该项时导致一个outofrange异常。

int[] refArray = randomNumber(value, arraySize);
            foreach (int i in refArray)
            {

                if (cbGame.SelectedIndex == 1)
                {
                    if (refArray[i] >= 2)
                    {
                        success4++;
                    }
                    if (refArray[i] == 1)
                    {
                        botch4++;
                    }
                }