矩阵类：

using System.Text;

namespace matrix.MatrixDemo
{
    public class Matrix
    {
        //矩阵的阶数 n行，m列
        private int n;
        private int m;
        //一维数组
        private int[,] table;

        public Matrix(int n = 0)
        {
            this.table = null;
            if (n > 0)
            {
                this.n = n;
                this.m = n;
                this.table = new int[n, m];
                for (int i = 0; i < n; i++)
                {
                    for (int j = 0; j < m; j++)
                    {
                        this.table[i, j] = 0;
                    }
                }
            }
        }

        public Matrix(int[,] matrix1, int n, int m)
        {
            if (n > 0 && m > 0 && matrix1 != null)
            {
                this.n = n;
                this.m = m;
                this.table = new int[n, m];
                for (int i = 0; i < n; i++)
                {
                    for (int j = 0; j < m; j++)
                    {
                        this.table[i, j] = matrix1[i, j];
                    }
                }
            }
        }


        public Matrix(Matrix matrix1)
        {
            this.n = matrix1.getRow();
            this.m = matrix1.getColumn();
            this.table = new int[n,m];
            for (int i = 0; i < n; i++)
            {
                for (int j = 0; j < m; j++)
                {
                    this.table[i, j] = matrix1.get(i,j);
                }
            }

        }


        public int getRow() {
            return n;
        }

        public int getColumn() {
            return m;
        }
        public int get(int i, int j){
            if(i>=0 && i<n && j>=0 && j<m){
                return this.table[i,j];
            }else{
                return -32767;
            }
        }

        public bool set(int i, int j, int k) {
            if(i>=0 && i<n && j>=0 && j<m) {
                this.table[i,j] = k;
                return true;
            }else {
                return false;    
            }
        }


        public static Matrix operator +(Matrix matrix1, Matrix matrix2){
            Matrix matrix3 = new Matrix(matrix1);
            int row = matrix1.getRow();
            int column = matrix1.getColumn();

            for(int i=0;i<row;i++){
                for(int j=0;j<column;j++){
                    int value = matrix1.get(i,j) +matrix2.get(i,j);
                    matrix3.set(i,j,value);
                }
            }
            return matrix3;
        }


        public override string ToString() {
            StringBuilder sb = new StringBuilder();
            sb.Append("矩阵:\n");
            for(int i = 0;i<n;i++){
                for(int j = 0;j<m;j++){
                    sb.Append(this.get(i,j));
                    sb.Append(" ");
                }
                sb.Append("\n");
            }

            return sb.ToString();
        }

    }
}

调用方法类：

using System;
using matrix.MatrixDemo;

namespace matrix
{
    class Program
    {
        static void Main(string[] args)
        {
            int [,] arr1 = {
                {1,2,3,4},
                {0,1,0,0},
                {0,0,1,0},
                {0,0,0,1}
            };
            int [,] arr2 = {
                {0,0,0,1},
                {0,0,1,0},
                {0,1,0,0},
                {1,0,0,0}
            };

            Matrix matrix1 = new Matrix(arr1, 4, 4);            
            Matrix matrix2 = new Matrix(arr2, 4, 4);
            Matrix matrix3 = matrix1 + matrix2;
            Console.Write(matrix3);
        }
    }
}

程序输出如下：

1.png