blob转base64位 base64位转blob

摘自http://www.cnblogs.com/fj99/p/5502130.html

base64转blob

function base64ToBlob(dataurl) {

var arr = dataurl.split(','),mime = arr[0].match(/:(.*?);/)[1],

bstr = atob(arr[1]),n = bstr.length,u8arr =new Uint8Array(n);

while(n--) {

u8arr[n] = bstr.charCodeAt(n);

}

return new Blob([u8arr],{type: mime});

}

blob 转 dataURL

function blobToDataURL(blob, callback) {

var a =new FileReader();

a.onload=function(e) {

callback(e.target.result);

}

a.readAsDataURL(blob);

}