我必须在我的程序中演示使用Lambdas / Actions / Delegates来使我的A-Level更复杂。 我知道如何使它们全部和（它们）做什么，但不知道何时使用它们。
有人能让我知道我的代码在哪里可以使用其中的一个，两个或全部吗？我不确定这是不是正确的地方，如果没有，请告诉我。
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
}
}
}
答案 0 :(得分：1)
首先，我必须同意乔恩：先把它弄干净。这是使用动作作为匿名委托/ lambda函数的lambda使用示例。您可能不得不摆弄它以使其工作
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
}