为什么我的数组抛出超出范围异常错误？

Question

Why does the following code throw an exception?

for (int i = 0; i <= Items.Length-1; i++)
{
    Console.WriteLine(Items[i,1]);
}

Exception:

System.IndexOutOfRangeException was unhandled
  Message="Index was outside the bounds of the array."
  Source="Es"
  StackTrace:
       at Es.Program.Main(String[] args) in C:\Users\Fero\Documents\Visual Studio 2005\Projects\Es\Es\Program.cs:line 19
       at System.AppDomain._nExecuteAssembly(Assembly assembly, String[] args)
       at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
       at System.Threading.ThreadHelper.ThreadStart()

Declaration of Items:

Function which gets the array of strings:

static string[,] ReadFromFile(string filename, int rowsF)
{
    StreamReader SR;
    string S;
    string[] S_split;

    SR = File.OpenText(filename);
    S = SR.ReadLine();

    string[,] myItems = new String[rowsF, 2];
    int row_number = 0;
    while (S != null)
    {
        S_split = S.Split('"');
        //temp_items[row_number,0] = 
        myItems[row_number,0] = S_split[1];
        myItems[row_number,1] = S_split[2];

        row_number++;
        S = SR.ReadLine();
    }
    SR.Close();
    return myItems;
}

string[,] Items = ReadFromFile(myFile, rowsF);

Answer 1

You have a straight two-dimensional array. Length gives you the total number of elements in the array, but you're using it to calculate the index for a single dimension. What you want is:

for (int i = 0; i < Items.GetLength(0); i++)
{
    Console.WriteLine(Items[i,1]);
}

Answer 2

Check the length of Items[i]. It appears to be a 2D array, and it's apparently not null, because you'd get a different exception for that, so it probably is just an empty array at Items[i], or only contains one item.

Check for:

Items[i] == null
Items[i].Length > 0

EDIT : Your additional code helped. When you split the string to initialize Items, for the item that's giving you trouble, check what you're storing at index 1. Other than that, I can't see a problem with it.

Answer 3

It's throwing an exception because Items[i].Length is < 2

you need to check that (Items[i].Length >= 2) before trying to access Items[i,1]

Answer 4

From what I see, there's a small chance one of the lines doesn't follow the format you require. It looks like you're retrieving text based on Quote (") delimitation, and S_split[] might not always have those number of fields.

A blank line at the end of the file, for example, will trigger the exception.

Answer 5

  S_split = S.Split('"'); //temp_items[row_number,0] = myItems[row_number,0] = S_split[1]; myItems[row_number,1] = S_split[2]; 

Are you sure you don't want S_Split[0] & S_Split[1]?

Should see the input file.