JavaScript save blob to localStorage

问题

I am trying to save blob data (favicon) retrieved via AJAX, to localStorage.

Code :

var xhr = new XMLHttpRequest();
xhr.open('GET', 
'http://g.etfv.co/http://www.google.com',
true);
xhr.responseType = "blob";
xhr.onload = function(e){ //Stringify blob...
    localStorage['icon'] = JSON.stringify(xhr.response);
    //reload the icon from storage
    var fr = new FileReader();
    fr.onload = 
        function(e) {
            document.getElementById("myicon").src = fr.result;
        }
    fr.readAsDataURL(JSON.parse(localStorage['icon']));
    }
xhr.send(null);

The code is adapted from here with minor modifications to make it work with localStorage. localStorage saves all data as strings, so blobs need to be stringified somehow before being saved.

JSON doesn't deal with blobs as one of it's supported types, so it's no surprise that this code fails.

Is there any way to get the blob into localStorage?

回答1:

Just store the blob as a data uri in local storage

var xhr = new XMLHttpRequest();
xhr.open('GET', 
'http://g.etfv.co/http://www.google.com',
true);
xhr.responseType = "blob";
xhr.onload = function(e){ //Stringify blob...
    //reload the icon from storage
    var fr = new FileReader();
    fr.onload = 
        function(e) {
            localStorage['icon'] = e.target.result;
            document.getElementById("myicon").src = localStorage['icon'];
        }
    fr.readAsDataURL(xhr.response);
}
xhr.send(null);

来源：https://stackoverflow.com/questions/21008732/javascript-save-blob-to-localstorage