Resolving C# non-static field, method or property "islandnum.Program.getIslandCount(int[][], int, int)" requires an object reference

Run a piece of code for a two-dimensional array in c#:

When the following code is called in the main function main

getIslandCount(map, row, col);

Error in error title:

A non-static field, method or property 'islandnum.Program.getIslandCount(int[][], int, int)' requires an object reference

Before the main function, this function is defined as follows:

public int getIslandCount(int[][] map, int row, int col)

Then just change the above line of code to:

public static int getIslandCount(int[][] map, int row, int col)

The error is solved, just add a static.