Как я могу использовать Lambda/Action/Delegate в моем коде?

Question

Я должен продемонстрировать использование Lambdas/Actions/Delegates в моей программе для моего уровня A, чтобы сделать его более сложным. Я знаю, как сделать все это и (что), что они делают, но не когда их использовать.

Может кто-нибудь сообщить мне, где в моем коде я могу использовать один, два или все из них? Я не был уверен, что это подходящее место для этого, дайте мне знать, если нет.

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

//Command-Line Arguements for SizeX and SizeY 

namespace prjT02L08_Predator_Prey 
{ 
    public partial class frmSim : Form 
    { 
     Point GridSize; //Creates a pair of X and Y co-ordinates 
     Random r = new Random(); //Used for any random number needed in the program 
     float FoodSpawnChance = 50; //The chance that food has of spawning 
     int SimTick = 0; //How long the program has been running for 
     int ImageScale = 7; //How much to scale the bitmap grid up for displaying 
     int SizeX = 60; //The number of pixels on the X axis 
     int SizeY = 60; //The number of pixels on the Y axis 

    bool StepDone = true; //Has one update of the simulation happened? 

    public frmSim() //Main constructor method 
    { 
     InitializeComponent(); 

     GridSize = new Point(SizeX, SizeY); //Sets the size of the grid using the size of the X and Y axis 
     AStar.Grid = Node.MakeGrid(GridSize.X, GridSize.Y, 10); 

     for (int i = 0; i < 10; i++) 
      new Mitosis(r.Next(0, SizeX) /*Produces a random number between 0 and the size of the X axis*/, 
       r.Next(0, SizeY)/*Random number between 0 and the size of the Y axis*/); //Adds new Mitosis bacteria for the first time 

     for (int i = 0; i < 8; i++) 
      new Meiosis(r.Next(0, SizeX), r.Next(0, SizeY)); //Adds new Meiosis bacteria for the first time 
     chkNaturalSpawn.Checked = true; //Sets the food's natural spawn to true, so it randomly spawns 
    } 

    private void UpdateSim() //Updates the whole simulation 
    { 
     UpdateVars(); //Updates all the variables in the simulation 

     if (SimTick == 20) //If the simulation has run for 20 ticks, 
      for (int i = 0; i < 10; i++) 
       new VirusP(1, 1); //Creates a new virus at the X position 1, and Y position 1 

     if (chkNaturalSpawn.Checked == true) //If natural spawning has been selected 
      SpawnFood(); //then try to spawn food 

     Entity.UpdateAll(SimTick); //Updates all entities 
    } 

    private void UpdateVars() //Updates all the variables in the simulation 
    { 
     SimTick++; //Each timer tick, this variable is incremented 
     tmrSimClock.Interval = trcInterval.Value; //The gap between ticks is set based of the trackbar (Which has been reversed right-to-left) 

     if (chkNaturalSpawn.Checked == true) //Checks if natural food spawning is enabled 
      FoodSpawnChance = trcFoodSpawn.Value; //then if true, sets the chance of food spawning to the value of the trackbar 

     VirusP.DoubleStepChance = trcPred2Step.Value; //The chance of the Virus moving two places instead of one is set of the trackbar 
    } 

    private void SpawnFood() //Attempts to spawn food at a random location 
    { 
     //Chance to spawn based on FoodSpawnChance variable 
     if (r.Next(0, 1000) < (FoodSpawnChance * 100)) //Uses a random number to determine whether food can spawn or not 
     { 
      int x = r.Next(0, GridSize.X); //Sets the value of x to a random number between 0 and the value of the Gridsize.X 
      int y = r.Next(0, GridSize.Y); //Sets the value of y to a random number between 0 and the value of the Gridsize.Y 

      if (!AStar.Grid[x, y].IsWall) //Checks if the random position chosen isn't a wall 
       new Food(x, y); //then if true, food is spawned at that position 

     } 
    } 

    private void frmSim_Load(object sender, EventArgs e) 
    { 

    } 

    private void btnStep_Click(object sender, EventArgs e) 
    { 
     if (StepDone == true) //Checks if the previous update from this button has already been completed or not - Prevents slow down 
     { 
      StepDone = false; 
      UpdateSim(); //Updates the simulation once 
      DrawSim(); //Redraws the bitmap image to show a visual update 
      StepDone = true; 
     } 
    } 

    private void DrawSim() //Creates the bitmap of the grid which is dispalyed on the screen and scales it up 
    { 
     Bitmap bmp = new Bitmap(GridSize.X, GridSize.Y); //Creates the bitmap specifying the width and height of it 
     //These two for loops loop through every part of the grid: 
     for (int x = 0; x < GridSize.X; x++) //For every value in the height of the grid 
     { 
      for (int y = 0; y < GridSize.Y; y++)//and every value in the width of the grid 
      { 
       Color Colour = Color.Black; //Creates a new color used to set the pixel colour on the bitmap (Empty space is black) 

       foreach (Entity e in Entity.GetEntitiesAt(x, y)) //For every entity a the current location... 
       { 
        if ((e as Food) != null) //If it is Food, set the colour to green 
         Colour = Color.FromArgb(Colour.R, 255, Colour.B); 
        else if ((e as Mitosis) != null) //If it is bacteria Mitosis, set the colour to blue 
         Colour = Color.FromArgb(Colour.R, Colour.G, 255); 
        else if ((e as Meiosis) != null) //If it is bacteria Meiosis, set the colour to gold 
         Colour = Color.Gold; 
        else //If it's none of these, the only entity left is the Virus, set the colour to red 
         Colour = Color.FromArgb(255, Colour.G, Colour.B); 
       } 

       if (AStar.Grid[x, y].IsWall) //If that location is a wall, set the colour to white 
        Colour = Color.White; 

       bmp.SetPixel(x, y, Colour); //Set the pixel at position x and y to the colour chosen above 
      } 
     } 

     //Scales up the bitmap into a new bitmap 
     Bitmap bmpscale = new Bitmap(GridSize.X * ImageScale, GridSize.Y * ImageScale); 
     for (int x = 0; x < GridSize.X; x++) 
     { 
      for (int y = 0; y < GridSize.Y; y++) 
      { 
       for (int sx = 0; sx < ImageScale; sx++) 
       { 
        for (int sy = 0; sy < ImageScale; sy++) 
        { 
         bmpscale.SetPixel(((x * ImageScale) + sx), ((y * ImageScale) + sy), bmp.GetPixel(x, y)); 
        } 
       } 
      } 
     } 

     this.CreateGraphics().DrawImage(bmpscale, new Point(10, 10)); //Draws the bitmap image at set co-ordinates on the form 
    } 

    private void tmrSimClock_Tick(object sender, EventArgs e) //Every time the timer updates 
    { 
     UpdateSim(); //Updates the simulation 
     DrawSim(); //Redraws the simulation 
    } 

    private void btnRun_Click(object sender, EventArgs e) 
    { 
     tmrSimClock.Enabled = !tmrSimClock.Enabled; //Put timer in opposite state 
     btnStep.Enabled = !btnStep.Enabled; //Put button in opposite state 

     if (tmrSimClock.Enabled) 
      btnRun.Text = "Running..."; 
     else 
      btnRun.Text = "Run"; 
    } 

    private void btnReset_Click(object sender, EventArgs e) 
    { 
     Entity.Entities = new List<Entity>(); //Recreates the list of entitites 
     SimTick = 0; //Restarts the simulation timer 
     tmrSimClock.Enabled = false; //Turns the timer off 
     for (int i = 0; i < 10; i++)//Recreates entities Mitosis and Meiosis 
     { 
      new Mitosis(r.Next(0, SizeX), r.Next(0, SizeY)); 
      new Meiosis(r.Next(0, SizeX), r.Next(0, SizeY)); 
     } 
     btnRun.Text = "Run"; 
    } 

    private void chkNaturalSpawn_CheckedChanged(object sender, EventArgs e) 
    { 
     lblFood.Enabled = chkNaturalSpawn.Checked == true ? true : false; //Turnery Statement 
     trcFoodSpawn.Enabled = chkNaturalSpawn.Checked == true ? true : false; //If checked is true, return true, else return false 
    } 
} 
} 

Answer 1

Во-первых, я должен согласиться с Джоном: сначала сделайте это аккуратным. Это пример использования лямбда, используя действие как анонимную функцию делегата/лямбда. Вы, возможно, придется играть на скрипке, чтобы заставить его работать

private void traverseBmp(Action<int, int> doIt) 
    { 
     for (int x = 0; x < GridSize.X; x++) //For every value in the height of the grid 
     { 
      for (int y = 0; y < GridSize.Y; y++)//and every value in the width of the grid 
      { 
       doIt(x, y); 
      } 
     } 

    private void DrawSim() //Creates the bitmap of the grid which is dispalyed on the screen and scales it up 
    { 
     Bitmap bmp = new Bitmap(GridSize.X, GridSize.Y); //Creates the bitmap specifying the width and height of it 
     //These two for loops loop through every part of the grid: 
     traverseBmp((x, y) => 
      { 
       Color Colour = Color.Black; 
        //Creates a new color used to set the pixel colour on the bitmap (Empty space is black) 

       foreach (Entity e in Entity.GetEntitiesAt(x, y)) //For every entity a the current location... 
       { 
        if ((e as Food) != null) //If it is Food, set the colour to green 
         Colour = Color.FromArgb(Colour.R, 255, Colour.B); 
        else if ((e as Mitosis) != null) //If it is bacteria Mitosis, set the colour to blue 
         Colour = Color.FromArgb(Colour.R, Colour.G, 255); 
        else if ((e as Meiosis) != null) //If it is bacteria Meiosis, set the colour to gold 
         Colour = Color.Gold; 
        else //If it's none of these, the only entity left is the Virus, set the colour to red 
         Colour = Color.FromArgb(255, Colour.G, Colour.B); 
       } 

       if (AStar.Grid[x, y].IsWall) //If that location is a wall, set the colour to white 
        Colour = Color.White; 

       bmp.SetPixel(x, y, Colour); //Set the pixel at position x and y to the colour chosen above 
      }); 

     //Scales up the bitmap into a new bitmap 
     Bitmap bmpscale = new Bitmap(GridSize.X * ImageScale, GridSize.Y * ImageScale); 
     traverseBmp((x,y) => 
      { 
       for (int sx = 0; sx < ImageScale; sx++) 
       { 
        for (int sy = 0; sy < ImageScale; sy++) 
        { 
         bmpscale.SetPixel(((x*ImageScale) + sx), ((y*ImageScale) + sy), bmp.GetPixel(x, y)); 
        } 
       } 
      }); 

     this.CreateGraphics().DrawImage(bmpscale, new Point(10, 10)); //Draws the bitmap image at set co-ordinates on the form 
    }