because you want to upload a compressed image in vue, convert the file to base64 first, and then compress it to upload to the oss platform

1. But now the files obtained by the oss platform are as follows. You don"t even have a suffix, but you can see the picture by typing the link in oss.
2. I downloaded the file to local, double-click the file, but was told that the file does not exist, so that delete can not be deleted. But it"s on the table.
3.base64 to file I console out is obviously an img file, how to upload to oss is a picture file. Not like this

//reader
            let reader = new FileReader();

            //base64
            reader.readAsDataURL(files[i]);
            //
            reader.onloadend = function() {
              let result = this.result;
              let img = new Image();
              img.src = result;
              // console.log("****************");
              // console.log(result.length);
              img.onload = function() {
                let data = self.compress(img);
                self.imgUrl = result;

                let blob = self.dataURItoBlob(data);
                self.file[self.file.length] = blob;
                if(self.file.length == self.all) {
                  var formData = new FormData();
                  for (var j = 0; j < self.file.length; jPP) {
                    formData.append("file[]", self.file[j]);
                  }

                  self.tirggerFile(formData);
                }
                
                
                
  compress(img) {
    let canvas = document.createElement("canvas");
    let ctx = canvas.getContext("2d");
    let initSize = img.src.length;
    let width = img.width;
    let height = img.height;
    canvas.width = width;
    canvas.height = height;
    // 
    ctx.fillStyle = "-sharpfff";
    ctx.fillRect(0, 0, canvas.width, canvas.height);
    ctx.drawImage(img, 0, 0, width, height);

    //
    let ndata = canvas.toDataURL("image/jpeg", 0.1);
    // console.log("**************");
    // console.log(ndata)
    // console.log(ndata.length);
    return ndata;
  },
  // base64bolb
  dataURItoBlob(base64Data) {
    var byteString;
    if (base64Data.split(",")[0].indexOf("base64") >= 0)
      byteString = atob(base64Data.split(",")[1]);
    else byteString = unescape(base64Data.split(",")[1]);
    var mimeString = base64Data
      .split(",")[0]
      .split(":")[1]
      .split(";")[0];
    var ia = new Uint8Array(byteString.length);
    for (var i = 0; i < byteString.length; iPP) {
      ia[i] = byteString.charCodeAt(i);
    }
    return new Blob([ia], { type: mimeString });
  },