2015-12-06 106 views
1

我一直在阅读(并尝试)我可以在此主题上找到的所有内容,但没有运气。我的目标是将来自arr_images的所有图像源加载到包含图像对象的数组中,然后在画布上绘制特定图像。JavaScript未将图像对象从数组加载到画布上

任何帮助非常感谢!提前致谢。

的index.html

<!DOCTYPE html> 
<html> 
<head lang="en"> 
<meta charset="UTF-8"> 
<title></title> 
<link rel="stylesheet" type="text/css" href="css/main.css"> 
<script src="js/jquery-2.1.4.min.js"></script> 
<script src="js/enginev2.js"></script> 
</head> 
<body> 
<canvas id="main" width="1000" height="500"></canvas> 
</body> 
</html> 

enginev2.js

var arr_images = ["images/player.jpg"]; 
var obj_images = []; 

$.each(arr_images, function(key, image) { 
    var img = new Image(); 
    img.src = image; 
    obj_images.push(img); 
}); 

var c = document.getElementById("main"); 
var ctx = c.getContext("2d"); 

$(document).ready(function() { 
    ctx.drawImage(obj_images[0], 0, 0, 100, 100); 
}); 

回答

2

我的猜测,现在是,当你尝试绘制图像加载不正确(文档可能是之前准备就绪图像完全加载)。

尝试使用IMG对象的回调函数调用您的ctx.drawImage功能:

img.onload = drawImage; // calls ctx.drawImage 
0
var arr_images = ["images/player.jpg"]; 
var obj_images = []; 

$.each(arr_images, function(key, image) { 
    var img = new Image(); 
    img.src = image; 
    obj_images.push(img); 
    img.onload = function() { 
     ctx.drawImage(obj_images[0], 0, 0, 100, 100); 
    } 
}); 

var c = document.getElementById("main"); 
var ctx = c.getContext("2d");