如何在嵌套的foreach中继续迭代

Question

Here is my simple example:

IList<string> files = new string[] { "file1", "file2", "file3" };
IList<string> words = new string[] { "first", "second", "third", "fourth", "fifth", "sixth" };

foreach (var file in files) {
    int i = 1;
    foreach (var word in words) {
        MessageBox.Show(i.ToString());
        i++;
    }
}

After every iteration, I want to see in the MessageBox 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 but it gives me 3 times 1 , 2 , 3 , 4 , 5 , 6

Is it possible which I want?

Answer 1

The reason why the counter " resets " itself is because you instruct it to do so:

foreach (var file in files) {
    int i = 1;               //<--- for each file, reset the counter i to 1
    foreach (var word in words) {
        MessageBox.Show(i.ToString());
        i++;
    }
}

You can get the behavior you aim by initializing the counter outside the outer loop:

int i = 1;                   //<--- initialize outside outer loop
foreach (var file in files) {
    foreach (var word in words) {
        MessageBox.Show(i.ToString());
        i++;
    }
}