调整数组大小时，为什么索引超出数组范围？

Question

这是我正在研究的程序的一小部分。 我试图通过创建另一个数组，将所有内容从第一个数组复制到第二个数组，然后让第一个数组引用第二个数组来手动调整数组的大小。

RoundInfo[] rounds = new RoundInfo[10];
int numRounds = 0;
RoundInfo ri;
RoundInfo[] newRI;

public void AddRound(int height, int speed)
        {
            if (numRounds >= rounds.Length) // creates a new array of RI objects if numRounds is greater than rounds.Length
            {
                newRI = new RoundInfo[numRounds + 1];
               // Console.WriteLine("numRounds: {0}   length: {1}", numRounds, rounds.Length); // me checking if the AddRound correctly increments numRounds, it does.
                //Console.WriteLine(newRI.Length);
                for (int i = 0; i < newRI.Length; i++)
                    newRI[i] = rounds[i]; // *THE PROGRAM CRASHES HERE*
                rounds = newRI;
                ri = new RoundInfo(height, speed);
                rounds[numRounds] = ri;
                numRounds++;

            }
            if (numRounds < rounds.Length) // the program goes through this fine
            {
                ri = new RoundInfo(height, speed);
                rounds[numRounds] = ri;
                numRounds++;
            }

        }

我不明白如果新数组更长的话为什么会崩溃。

Answer 1

因为当numRounds == rounds.Length时，您要先输入。 其中10 == rounds.Length（是10）

然后添加

        if (numRounds >= rounds.Length) // here you're having numRounds as 10
        {
            newRI = new RoundInfo[numRounds + 1]; //here you're adding + 1 will get newRI = new RoundInfo[11]
            for (int i = 0; i < newRI.Length; i++)
                newRI[i] = rounds[i]; // *THE PROGRAM CRASHES HERE*
                                      // so in here your program will crash due to indexOutOfBOunds because newRI[11] = rounds[11];
                                      //rounds[11] is not existing
            rounds = newRI;
            ri = new RoundInfo(height, speed);
            rounds[numRounds] = ri;
            numRounds++;
        }

您可以通过不在newRI上添加+1来防止这种情况

        if (numRounds >= rounds.Length)
        {
            newRI = new RoundInfo[numRounds]; //remove +1 here
            //etc codes
        }

---

我不知道你这部分打算

//如果numRounds大于rounds，则创建一个新的RI对象数组。

复制数组但超过先前的数组长度是不可能的。 看来您正在尝试做（newArray [oldArray.Length + 1] == oldArray [oldArray.Length]），因为它确实超出了您的范围。

newArray [11]不能具有oldArray [11]，因为它不存在

您可以尝试的是oldArray的长度，而不是new

for (int i = 0; i < rounds.Length; i++)
            newRI[i] = rounds[i];