HTML5 Canvas toDataUrl - 上传gif解决方法 [英] HTML5 Canvas toDataUrl - Upload gif workaround
问题描述
我想知道是否可以在canvas元素中预览.gif图像并将其作为'image / gif'文件类型上传。我发现了这个 SO问题,但它错误地提到了.gif在标题中但没有提及如何在任何回复/评论中处理画布和GIF。
I'm wondering if it's possible to preview a .gif image within a canvas element and uploaded it as an 'image/gif' file type. I found this SO question, but it incorrectly mentions .gif in the title but no references on how to deal with canvas and gifs within any of the responses/comments.
根据文档,'image / gif'不是接受 toDataUrl
的类型。是否有一个解决方法/ lib允许我在预览画布中放置一个gif并将画布文件上传为gif?
According to the docs, 'image/gif' is not an accepted type for toDataUrl
. Is there a workaround / lib which will allow me to place a gif within a preview canvas and upload the canvas file as a gif?
推荐答案
< h2> FileReader.readAsDataURL()
来自 mozilla.org
function previewFile() {
var preview = document.querySelector('img');
var file = document.querySelector('input[type=file]').files[0];
var reader = new FileReader();
reader.onloadend = function() {
preview.src = reader.result;
}
if (file) {
reader.readAsDataURL(file);
} else {
preview.src = "";
}
}
<input type="file" onchange="previewFile()">
<br>
<img src="" height="200" alt="Image preview...">
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