methods: { async upfile() { let upload = document.getElementById("file1"); let f = upload.files[0]; let size = 1024 * 100; let start = 0, end = 0; let data; while (start < f.size) { end += size; if (end > f.size) end = f.size; console.log("size: %d start: %d end: %d ", f.size, start, end); data = f.slice(start, end); start = end; let r = await fetch("http://127.0.0.1:8080/upload", { method: "POST", body: data, }); console.log(await r.json()); data = null; } },