javascript - How to convert a byte array into an image?

Question

Using Javascript, I'm making an AJAX call to a WCF service, and it is returning a byte array. How can I convert that to an image and display it on the web page?

Answer 1

I realize this is an old thread, but I managed to do this through an AJAX call on a web service and thought I'd share...

• I have an image in my page already:

   <img id="ItemPreview" src="" />
  

• AJAX:

  $.ajax({
          type: 'POST',
          contentType: 'application/json; charset=utf-8',
          dataType: 'json',
          timeout: 10000,
          url: 'Common.asmx/GetItemPreview',
          data: '{"id":"' + document.getElementById("AwardDropDown").value + '"}',
          success: function (data) {
              if (data.d != null) {
                  var results = jQuery.parseJSON(data.d);
                  for (var key in results) {
                      //the results is a base64 string.  convert it to an image and assign as 'src'
                      document.getElementById("ItemPreview").src = "data:image/png;base64," + results[key];
                  }
              }
          }
      });
  

My 'GetItemPreview' code queries a SQL server where I have an image stored as a base64 string and returns that field as the 'results':

     string itemPreview = DB.ExecuteScalar(String.Format("SELECT [avatarImage] FROM [avatar_item_template] WHERE [id] = {0}", DB.Sanitize(id)));
     results.Add("Success", itemPreview);
     return json.Serialize(results);

The magic is in the AJAX call at this line:

     document.getElementById("ItemPreview").src = "data:image/png;base64," + results[key];

Enjoy!