double latSource = Convert.ToDouble(lat1); code example
Example 1: convert int to double c#
int x = 420;
double y = Convert.ToDouble(x);
Example 2: convert string to double c#
Console.WriteLine(Convert.ToDouble("104.1169"));
int x = 420;
double y = Convert.ToDouble(x);
Console.WriteLine(Convert.ToDouble("104.1169"));