我正在嘗試使用Raymond Camden的水印代碼以及來自Phonegap相機API的示例。畫布未定義
相機運作良好。
然而,
Uncaught ReferenceError: canvas is not defined
示於logcat中。
我試圖將函數中的變量放在全局變量中。但錯誤仍然出現。我的代碼如下:
<!DOCTYPE html>
<head>
<script type="text/javascript" charset="utf-8" src="cordova-2.7.0.js"></script>
<link rel="stylesheet" type="text/css" href="jquery/css/jquery.mobile-1.3.1.min.css"/>
<script type="text/javascript" charset="utf-8" src="jquery/jquery-1.9.1.min.js"></script>
<script type="text/javascript" charset="utf-8" src="jquery/jquery.mobile-1.3.1.min.js"><script>
<script type="text/javascript" charset="utf-8">
var watermark;
var canvasDOM;
var canvas;
document.addEventListener("deviceready",onDeviceReady,false);
function onDeviceReady() {
} </script>
<script type="text/javascript" charset="utf-8">
canvasDOM = $("myCanvas")[0];
canvas = canvasDOM.getContext("2d");
watermark = new Image();
watermark.src = "q1.jpg";
function cybershot() {
navigator.camera.getPicture(camSuccess, camError, {quality: 75, targetWidth: 400, targetHeight: 400, destinationType: Camera.DestinationType.FILE_URI});
}
function camError(e) {
console.log("Camera Error");
console.log(JSON.stringify(e));
}
function camSuccess(picuri) {
console.log("Camera Success");
var img = new Image();
img.src=picuri;
img.onload = function(e) {
canvas.drawImage(img, 0, 0);
canvas.drawImage(watermark, canvasDOM.width-watermark.width, canvasDOM.height - watermark.height);
}
}
</script>
<style>
#myCanvas {
width: 400px;
height: 400px;
}
</style>
</head>
<body>
<h1>Watermark Camera</h1>
<button onclick="cybershot();">Capture Photo</button> <br>
<p/>
<canvas id="myCanvas"></canvas>
</body>
</html>
我試過你的解決方案,我能夠縮小這個錯誤。現在,我發現getContext未能被調用。我想知道任何可能的建議? @Gajotres –
我解決了這個問題,現在完美工作。非常感謝您的意見和建議。 –