非同步載入圖片函式封裝(使用Promise)
阿新 • • 發佈:2020-12-28
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<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
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<body>
<script>
loadImageAsync("./loadImg.jpg").then(image => document.body.appendChild(image))
// 非同步載入圖片函式封裝
function loadImageAsync(url) {
return new Promise(function(resolve, reject) {
const image = new Image();
image.src = url;
image.onload = function() {
resolve(image);
};
image.onerror = function() {
reject(new Error('Could not load image at ' + url));
};
});
}
</script>
</body>
</html>