用Javascript对象在画布上画板

Question

I want to create a simple game with Javascript and using canvas to show it. 我想用Javascript创建一个简单的游戏，并使用画布显示它。 I have an object for the board, and don't understand how to draw the col and row on the canvas, using the board object previously generated. 我有一个用于木板的对象，并且不理解如何使用先前生成的木板对象在画布上绘制行和行。

I have tried to make the function drawBoard, a prototype of Board, to use the this.width and this.height. 我试图使函数drawBoard（Board的原型）使用this.width和this.height。 But it doesn't use these values. 但是它不使用这些值。

I am quite lost about how to reuse the object properties (width and height) in this function drawing the board. 我对于如何在此功能板上重用对象属性（宽度和高度）感到迷茫。 Quite new at canvas. 在画布上相当新。

<html>
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-compatible" content="IE-edge">
<meta name="viewport" content="width=device-width, initial-scale-1">
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/animate.css/3.7.0/animate.css">
<script src="https://code.jquery.com/jquery-3.3.1.js" integrity="sha256-2Kok7MbOyxpgUVvAk/HJ2jigOSYS2auK4Pfzbm7uH60=" crossorigin="anonymous"></script>

  <title>Lava Temple</title>

<style>
* {
  padding: 0;
  border: 0;
}

body{
  background-color: #181818;
}

#board {
  display: block;
  background-color: white;
  margin: 0 auto;
  margin-top: 100px;
}
</style>

</head>
<body>
    <canvas id="board" width="800" height="800"></canvas>

<script>

function Board(width, height) {
  this.width = width;
  this.height = height;
  this.chartBoard = [];

  for (var i = 0; i < this.width; i++) {
    const row = [];
    this.chartBoard.push(row);
    for (var j = 0; j < this.height; j++) {
        const col = {};
        row.push(col);
    }
  }
}

let board = new Board(10, 10);
console.log(board);

const canvas = document.getElementById('board');
const ctx = canvas.getContext('2d');

Board.prototype.drawBoard = drawBoard;

function drawBoard() {

  for (var i = 0; i < this.width; i++) {
    for (var j = 0; j < this.height; j++) {
        ctx.beginPath();
        ctx.strokeStyle = 'black';
        ctx.strokeRect(j * 80, i * 80, 80, 80);
        ctx.closePath();
    }
  }
}

drawBoard();

</script>

</body>
</html>

Actual results: There is a canvas and a board object create, visible in the console. 实际结果：在控制台中可见一个画布和一个木板对象。

Expected results: That this board created is also drawn on the canvas with black strokes. 预期结果：该板创建时也在黑色笔划上绘制在画布上。

Why: This board object will then contain the objects Players / Weapons... 原因：此棋盘对象将包含玩家/武器...

Answer 1

You need to use Board.prototype.drawBoard = function() {.... Then when you call drawBoard() you call it like this: board.drawBoard() because it's a method of the board object. 您需要使用Board.prototype.drawBoard = function() {....然后，当您调用drawBoard()您应这样称呼它： board.drawBoard()因为它是board对象的一种方法。

 function Board(width, height) { this.width = width; this.height = height; this.chartBoard = []; for (var i = 0; i < this.width; i++) { const row = []; this.chartBoard.push(row); for (var j = 0; j < this.height; j++) { const col = {}; row.push(col); } } } Board.prototype.drawBoard = function() { for (var i = 0; i < this.width; i++) { for (var j = 0; j < this.height; j++) { ctx.beginPath(); ctx.strokeStyle = "black"; ctx.strokeRect(j * 80, i * 80, 80, 80); ctx.closePath(); } } }; let board = new Board(10, 10); const canvas = document.getElementById("board"); const ctx = canvas.getContext("2d"); board.drawBoard();

 * { padding: 0; border: 0; } body{ background-color: #181818; } #board { display: block; background-color: white; margin: 0 auto; margin-top: 100px; }

 <canvas id="board" width="800" height="800"></canvas>

用Javascript对象在画布上画板

问题描述

1 个解决方案

解决方案1
2 已采纳 2019-01-17 09:00:17

用Javascript对象在画布上画板

问题描述

1 个解决方案

解决方案1 2 已采纳 2019-01-17 09:00:17

解决方案1
2 已采纳 2019-01-17 09:00:17