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我正在尝试在画布上绘制一组图像，但没有绘制任何内容！以下是我的代码！我也在尝试了解 phonegap 和 javascript index.html：

    <!DOCTYPE html>
<html>
<head>
<title>Minecraft Background Check</title>
</head>
<body>
<canvas id="mycanvas" style="position:fixed; top:0; left:0; border:1px solid #c3c3c3; width: 100%; height: 100%;"></canvas>
<script type="text/javascript" src="cordova-2.5.0.js"></script>
<script type="text/javascript">
document.addEventListener("deviceready",ondeviceReady,false);
function onDeviceReady () {}
    //get element by id 
var c = document.getElementById("mycanvas");
var ctx = c.getContext("2d");
    //array image which need to draw in canvas
var image = ["img/image12","img/image13","img/image14","img/image15","img/image10"];
var m_arrImages = {};
for (var src in image) {
    m_arrImages[src] = new Image();

    m_arrImages[src].src = image[src];
}
var imagePositionsX = [20, 80, 140, 200, 260, 320, 380, 440, 500, 560];
var imagePositionsY = [20, 60, 100, 140, 180, 220, 260, 300, 340, 380];
var i, x, y;
for (i = 0; i < m_arrImages.length; i++) {
    x = imagePositionsX[ Math.floor(Math.random()*10) ];
    y = imagePositionsY[ Math.floor(Math.random()*10) ];

    ctx.drawImage(m_arrImages[i], x, y, 50, 50);
}
</script>
</body>
</html>
4

2 回答 2

2

您已将函数设置ondeviceReady为在deviceready事件中运行，但未定义该函数。您已经定义了一个名为onDeviceReady. Javascript 变量和函数名称区分大小写，因此在deviceready事件中不会运行任何内容。

改变：

document.addEventListener("deviceready",ondeviceReady,false);

至

document.addEventListener("deviceready",onDeviceReady,false);
于 2013-03-08T08:53:03.060 回答
1

可能是我错了，但是..“m_arrImages” - 它只是带有字符串的数组，而不是图像，不是吗？

我想，它应该是这样的：

var m_arrImages = {};
for (var src in image) {
    m_arrImages[src] = new Image();
    m_arrImages[src].src = image[src];
}
于 2013-03-08T08:57:32.037 回答