Why does declaring a variable of the same name as in for loop causes variable name ambiguity in C# in opposition to Java [duplicate]

This question already has an answer here:

• C# Variable Scoping 3 answers

As for Java refugee this code is perfectly fine. The int i lives in the loop only and the second int i causes no conflict. So there should be no problem. Altough, This code in C# causes i variable ambiguity.

static void Main(String[] args)
{
    for (int i = 0; i < 10; i++)
    {
    }
    int i = 0;
    while (i < 10) { i++; }
}

Thus(beign naive) this code should be valid

static void Main(String[] args)
{
    for (int i = 0; i < 10; i++)
    {
    }
    i++;
}

but it says the i variable is not declared which as expected is true. Finally only nesting second int i in the block fixes the ambiguity:

static void Main(String[] args)
{
    for (int i = 0; i < 10; i++)
    {
    }
    {
        int i = 0;
        while (i < 10) { i++; }
    }
}

The question is: what rule/mechanism of C# language causes variable name ambiguity in the first example given?

The printscreen from VS2013: