ArrayBuffer和Base64互相转换

//ArrayBuffer转base64
function translateArrayBufferToBase64(buffer){
    let binaryStr = "";
    const bytes = new Uint8Array(buffer);
    for(let i=0;len = bytes.byteLength;i<len;i++){
        binaryStr +=String.fromCharCode(bytes [i]);    
    }
    return window.btoa(binaryStr );
}

//base64转ArrayBuffer

function translateBase64ToArrayBuffer(base64){

    const binaryStr = window.atob(base64);
    const byteLength = binaryStr.length;
    const bytes = new Uint8Array(byteLength);
    for(let i=0;i<byteLength;i++){
        bytes[i] = binary.charCodeAt(i);
    }
    return bytes.buffer;
}