C# 字典按位置打印列表值

Question

From this example: https://stackoverflow.com/a/27034916/1312879

I have this kind of dictionary

Dictionary<int, List<string>> fileList = new Dictionary<int, List<string>>();

The example prints "fijo", "Frigy", "lijo", "liji", "vimal", "vilma"

How can I print "fijo", "lijo", "vimal", "Frigy", "liji", "vilma", I mean all the [0] position of each list, the [1] position and so on

Answer 1

You can code pretty much as you said:

foreach (var kvp in fileList)
{
    Console.WriteLine (kvp.Value[0]);
}
foreach (var kvp in fileList)
{
    Console.WriteLine (kvp.Value[1]);
}

And if there is more item in the inner list, you might want to use a loop for that, assuming they all have the same length:

for (int i = 0; i < fileList.First().Value.Count; i++)
{
    foreach (var kvp in fileList)
    {
        Console.WriteLine (kvp.Value[i]);
    }
}

Answer 2

Here you go:

for(int i=0; i < fileList.Values.Max(v=> v==null ? 0 : v.Length); i++)
{
    foreach(var keyValuePair in fileList)
    {
        if(kvp.Value == null || i >= kvp.Value.Length)
            continue;
        Console.WriteLine(kvp.Value[i]);
    }
}

However, I wonder reason behind traversing data structure in columnar fashion when it was created based on rows (or vice versa). You may be better off using different data structure that can serve all use cases.