图片上传时base64转成formData

export const  base64ToBlobios = (base64Str) => {
    let byteCharacters = atob(base64Str);
    let byteNumbers = new ArrayBuffer(byteCharacters.length);
    let byteArray = new Uint8Array(byteNumbers);
    for (let i = 0; i < byteCharacters.length; i++) {
        byteArray[i] = byteCharacters.charCodeAt(i);
    }
    let blob = new Blob([byteNumbers], { type: "image/jpeg" });
    let formData = new FormData();
    formData.append("file", blob, new Date().getTime() + ".png");
    return formData;
}