IndexOutOfRange on GetFiles

Question

我试图阅读大量的文件，并将一些信息存储在字典中。我的完整代码是：

[HttpGet("[action]")]

public JsonResult GenerateMapFiles()
{
    Dictionary<string, List<Tuple<string, ushort>>>[] CodeMapping = new Dictionary<string, List<Tuple<string, ushort>>>[256];

    /* Pre-creating some dictionaries */
    CodeMapping[2] = new  Dictionary<string, List<Tuple<string, ushort>>>(256);
    CodeMapping[8] = new  Dictionary<string, List<Tuple<string, ushort>>>(256);
    CodeMapping[16] = new  Dictionary<string, List<Tuple<string, ushort>>>(256);
    CodeMapping[32] = new  Dictionary<string, List<Tuple<string, ushort>>>(256);
    CodeMapping[64] = new  Dictionary<string, List<Tuple<string, ushort>>>(256);
    CodeMapping[128] = new  Dictionary<string, List<Tuple<string, ushort>>>(256);
    CodeMapping[256] = new  Dictionary<string, List<Tuple<string, ushort>>>(256);

    string[] fileList = System.IO.Directory.GetFiles("C:\\mySQL");

    /* Processing code was here, but I commented it and it is still generating exception */

    return Json(CodeMapping);
}

行string[] fileList = System.IO.Directory.GetFiles("C:\\mySQL");引发一个异常：

Exception thrown: 'System.IndexOutOfRangeException' in XXXXX.dll: 'Index was outside the bounds of the array.'

如果我对CodeMappingX赋值进行注释，则没有错误，并且填充了fileList。我不明白前几行为什么会影响到这一行。有人能向我解释原因吗？

Answer 1

好的，我在提交时找到了解决方案，它显然是Visual的一个错误，在调试模式中没有指向正确的行。我的第一句话应该是：

Dictionary<string, List<Tuple<string, ushort>>>[] CodeMapping = new Dictionary<string, List<Tuple<string, ushort>>>[257];

Answer 2

我认为您应该在n-1位置上创建字典，因为如果集合了256个元素，则最大索引将从0到255。

所以你把这个改写成：

/* Pre-creating some dictionaries */
    CodeMapping[1] = new  Dictionary<string, List<Tuple<string, ushort>>>(256);
    CodeMapping[7] = new  Dictionary<string, List<Tuple<string, ushort>>>(256);
    CodeMapping[15] = new  Dictionary<string, List<Tuple<string, ushort>>>(256);
    CodeMapping[31] = new  Dictionary<string, List<Tuple<string, ushort>>>(256);
    CodeMapping[63] = new  Dictionary<string, List<Tuple<string, ushort>>>(256);
    CodeMapping[127] = new  Dictionary<string, List<Tuple<string, ushort>>>(256);
    CodeMapping[255] = new  Dictionary<string, List<Tuple<string, ushort>>>(256);