[C#]列舉(enum)的使用

Code:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        enum Shape : int
        {
            Circle=0,
            Line=1,
            Arc=2
        }

        private void Draw(int vType)
        {
            Graphics g;
            Pen p = new Pen(Color.Red);
            g = this.CreateGraphics();
            g.Clear(Color.White);

            switch (vType)
            {
                case    0:
                    g.DrawEllipse(p, 90, 30, 90, 90);
                    break;
                case    1:
                    g.DrawLine(p, 90, 50, 180, 100);
                    break;
                case    2:
                    g.DrawArc(p, 90, 30, 90, 90, 0, 250);
                    break;

                default:
                    MessageBox.Show("沒這個喔");
                    break;
            }
        }

        private void Draw(Shape vType)
        {
            Graphics g;
            Pen p = new Pen(Color.Red);
            g = this.CreateGraphics();
            g.Clear(Color.White);

            switch (vType)
            {
                case Shape.Circle:
                    g.DrawEllipse(p, 60, 30, 90, 90);
                    break;
                case Shape.Line:
                    g.DrawLine(p, 60, 50, 180, 100);
                    break;
                case Shape.Arc:
                    g.DrawArc(p, 60, 30, 90, 90, 0, 250);
                    break;

                default:
                    MessageBox.Show("沒這個喔");
                    break;
            }
        }

        private void BTN_Circle_Click(object sender, EventArgs e)
        {
            //Draw(0);
            Draw(Shape.Circle);
        }

        private void BTN_LINE_Click(object sender, EventArgs e)
        {
            //Draw(1);
            Draw(Shape.Line);
        }

        private void BTN_Arc_Click(object sender, EventArgs e)
        {
            //Draw(2);
            Draw(Shape.Arc);
        }
    }
}

[C#]排序方法比較

問題：
透過內建函式做排序真的會比較快嗎？

前言：
一般而言函式都是透過優化而產出的，所以理論上而言會是比較快。
但是一切都要透過驗證，所以做了以下實驗，透過一些方式做實驗發現...

Code:

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

namespace ConsoleApplication3
{
    class Program
    {
        static void Main(string[] args)
        {
            int[] arrayMax = new int[10000000];
            int[] arrayMax2 = new int[10000000];
            int[] arrayMax3 = new int[10000000];
            for (int i = 0; i <= arrayMax.GetUpperBound(0); i++)
            {
                Random rnd = new Random();
                arrayMax[i] = rnd.Next();
                arrayMax2[i] = arrayMax[i];
                arrayMax3[i] = arrayMax[i];
            }

            /*
             *  方法一，use sort
             */
            DateTime start2 = DateTime.Now;
            Console.WriteLine("Start:" + start2.ToString() + "\n");
            Array.Sort(arrayMax2);
            Console.WriteLine("Max is:" + arrayMax2[arrayMax2.Length-1] + "\n");
            Console.WriteLine("End:" + DateTime.Now.Subtract(start2) + "\n");

            Console.WriteLine("*** next one ***\n");

            /*
             *  方法二，迴圈尋找
             */
            DateTime start = DateTime.Now;
            Console.WriteLine("Start:" + start.ToString() + "\n");
            Console.WriteLine("Max is:{0}\n", GetMax(ref arrayMax));
            Console.WriteLine("End:" + DateTime.Now.Subtract(start) + "\n");

            /*
             *  方法三，use sort and Reverse
             */
            DateTime start3 = DateTime.Now;
            Console.WriteLine("Start:" + start3.ToString() + "\n");
            Array.Sort(arrayMax3);
            Array.Reverse(arrayMax3);
            Console.WriteLine("Max is:" + arrayMax3[0] + "\n");
            Console.WriteLine("End:" + DateTime.Now.Subtract(start3) + "\n");

            Console.WriteLine("*** next one ***\n");

            Console.Read();
        }

        private static int GetMax(ref int[] arrayMax)
        {
            int i, max;
            max = arrayMax[0];
            for (i = 0; i <= arrayMax.GetUpperBound(0); i++)
            {
                if (max < arrayMax[i])
                {
                    max = arrayMax[i];
                }
            }
            return max;
        }
    }
}

結果：
迴圈比較快...

備註：
End為執行的時間，如果驗證方式有誤，麻煩不吝指教。

[C#]引數的傳遞方式

問題：
引數的傳遞方式？
參考：稍微靠靠腰

Code：

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

namespace ConsoleApplication2
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("\n *** 一般函式傳遞 *** \n");
            int a = 10, b = 20;
            
            Console.WriteLine("\n 未進入函式前\t\t:a={0} \t b={1}", a, b);
           
            CallValues(a, b);
            Console.WriteLine("\n 進入函式後\t\t:a={0} \t b={1}", a, b);

            CallValuesUseRef(ref a, ref b);
            Console.WriteLine("\n 進入函式後\t\t:a={0} \t b={1}", a, b);

            int initX, initY;
            Console.WriteLine("\n 進入函式前\t\t:initX,initY 沒有初始值");
            CallValuesUseOut(out initX, out initY);
            Console.WriteLine("\n 進入函式後\t\t:initX={0} \t initY={1}", initX, initY);

            Console.Read();
        }

        private static void CallValuesUseOut(out int x, out int y)
        {
            int z;
            x = 20;
            y = 30;
            Console.WriteLine("\n 函式內 交換前\t\t:x={0} \t y={1}", x, y);

            z = x;
            x = y;
            y = z;

            Console.WriteLine("\n 函式內 交換後\t\t:x={0} \t y={1}", x, y);

        }

        private static void CallValuesUseRef(ref int x, ref int y)
        {
            int z;
            x = 20;
            y = 30;
            Console.WriteLine("\n 函式內 交換前\t\t:x={0} \t y={1}", x, y);

            z = x;
            x = y;
            y = z;

            Console.WriteLine("\n 函式內 交換後\t\t:x={0} \t y={1}", x, y);
        }

        private static void CallValues(int x, int y)
        {
            int z;
            x = 20;
            y = 30;
            Console.WriteLine("\n函式內 交換前\t\t:x={0} \t y={1}", x, y);

            z = x;
            x = y;
            y = z;

            Console.WriteLine("\n函式內 交換後\t\t:x={0} \t y={1}", x, y);
        }
    }
}

結果：