如何使用Javascript从给定的URL下载GIF

问题描述

我正在尝试从Giphy 下载GIF （只需要下载它，就不需要在浏览器中显示它）。

我尝试在此问题this question中使用该解决方案，但是它会下载静态图片：

function download_img(e,link){
    var image = new Image();
    image.crossOrigin = "anonymous";
    image.src = link;
    image.onload = function () {
        var canvas = document.createElement('canvas');
        canvas.width = this.naturalWidth; // or 'width' if you want a special/scaled size
        canvas.height = this.naturalHeight; // or 'height' if you want a special/scaled size
        canvas.getContext('2d').drawImage(this,0);
        var blob;
        // ... get as Data URI
        if (image.src.indexOf(".jpg") > -1) {
            blob = canvas.toDataURL("image/jpeg");
        } else if (image.src.indexOf(".png") > -1) {
            blob = canvas.toDataURL("image/png");
        } else if (image.src.indexOf(".gif") > -1) {
            blob = canvas.toDataURL("image/gif");
        } else {
            blob = canvas.toDataURL("image/png");
        }
        tempbtn = document.createElement('a');
        tempbtn.href = blob;
        tempbtn.download = 'giphy.gif'; // or define your own name. 
        tempbtn.click();
        tempbtn.remove(); 
    };
}

<a href="#" onclick="download_img(this,'https://media2.giphy.com/media/DvyLQztQwmyAM/giphy.gif?cid=e9ff928175irq2ybzjyiuicjuxk21vv4jyyn0ut5o0d7co50&rid=giphy.gif')"  > Descargar gif </a>

我还想知道为什么需要创建一个new Image();和一个canvas tag

解决方法

通过在文档中附加链接，我也设法在Chrome和Firefox中也可以使用此功能。

var link = document.createElement('a');
link.href = 'images.jpg';
link.download = 'Download.jpg';
document.body.appendChild(link);
link.click();
document.body.removeChild(link);

,

这对我有用，我从这里获取了一些代码 https://randomtutes.com/2019/08/02/download-blob-as-file-in-javascript/

(async () => {
  //create new a element
  let a = document.createElement('a');
  // get image as blob
  let response = await fetch('https://media2.giphy.com/media/DvyLQztQwmyAM/giphy.gif?cid=e9ff928175irq2ybzjyiuicjuxk21vv4jyyn0ut5o0d7co50&rid=giphy.gif');
  let file = await response.blob();
  // use download attribute https://developer.mozilla.org/en-US/docs/Web/HTML/Element/a#Attributes
  a.download = 'myGif';
  a.href = window.URL.createObjectURL(file);
  //store download url in javascript https://developer.mozilla.org/en-US/docs/Learn/HTML/Howto/Use_data_attributes#JavaScript_access
  a.dataset.downloadurl = ['application/octet-stream',a.download,a.href].join(':');
  //click on element to start download
  a.click();
})();