C# 静态方法调用非静态方法

转载：http://blog.csdn.net/seattle1215/article/details/6657814

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace Cash
{
    class Program
    {
        static void Main(string[] args)
        {
            (new Program()).run();

            // writeFee(calculate(dailyRate, workDay));
            // 对于非 static 方法，若想像上面这样直接调用则会报以下错
            // Error    1 An object reference is required
            // for the non-static field, method, or
            // property 'Cash.Program.readDouble(string)'

            printfOtherthing("static method is called.");        // static 方法可直接调用
            Program program = new Program();        // 非 static 方法需要先创建一个对象
                                                    // 然后用对象调用
            program.printSomething("non-static menthod is called.");
        }

        public void run()
        {
            double dailyRate = readDouble("please enter your rate: ");
            int workDay = readInt("please enter your days of working: ");
            writeFee(calculate(dailyRate, workDay));
        }

        private void writeFee(double p)
        {
            Console.WriteLine("The consultant's fee is: {0}", p * 1.6);
        }

        private double calculate(double dailyRate, int workDay)
        {
            return dailyRate * workDay;
        }

        private int readInt(string p)
        {
            Console.WriteLine(p);
            string a = Console.ReadLine();          // 读取输入的字符（readline读取的
                                                    // 字符都是 string 类型）
            return int.Parse(a);                    // 把 a 转换为 int 类型，并返回
        }

        private double readDouble(string p)
        {
            Console.WriteLine(p);
            string line = Console.ReadLine();
            return double.Parse(line);
        }

        private void printSomething(string a)       // non-static method
        {
            Console.WriteLine(a);
        }

        private static void printfOtherthing(string a)          // static method
        {
            Console.WriteLine(a);
        }
    }
}
静态方法是无法直接调用非静态方法的，可以通过对象的引用来调用非静态方法，静态方法存储在内存中，而非静态方法是由对象的实例化来创建的，所以要通过对象的引用在静态方法中调用非静态方法，非静态方法是与对象实例化共生共亡