前端如何下载文件？

Question

后端返回了：

我需要把arraybuffer数据还原成file
并且自动开始下载这个file

我这样写了：

then(res => {
          console.log(res);
          const reader = new FileReader();
          reader.readAsArrayBuffer(res.blob.data);
          reader.onload = e => {
            const a = document.createElement("a");
            a.download = res.name;
            a.href = e.target.result;
            document.body.appendChild(a);
            a.click();
            document.body.removeChild(a);
          };
          reader.onerror = e => {
            console.log(e);
            throw e;
          };
        })

但是不行 怎么做？

Answer 1

// 应该是你想要的

var saveData = (function () {
    var a = document.createElement("a");
    document.body.appendChild(a);
    a.style = "display: none";
    return function (data, fileName) {
        var json = JSON.stringify(data),
            blob = new Blob([json], {type: "octet/stream"}),
            url = window.URL.createObjectURL(blob);
        a.href = url;
        a.download = fileName;
        a.click();
        window.URL.revokeObjectURL(url);
    };
}());

var data = { x: 42, s: "hello, world", d: new Date() },
    fileName = "my-download.json";

saveData(data, fileName);