how to judge if a file is exist

Unity Engine
1

hello i want to use script to upload a outside picture to show on a button,but i am afraid if the link isn’t exist but seams not work, i can got the pic to the button when it exist ,but i can’t change the button’s picture to a default pic when it wan’t exist help

var download = new WWW (“…/Assets/” + “mypic.jpg”);
yield download;

var productPic:Texture = download.texture;

if (productPic==null){

//if the file not exist ,i am not sure what to use ,anyway this isn’t work

getFile( “/Product/Default/”+ DefaultTexture.jpg);
productPic = download.texture;

print(“find error”); }

help help
more problem heppend to the text and bytes, help please
Jonny thanks

2

The WWW.error value will usually tell you if the file was not found (it’s the usual HTTP 404 error). However, you should be careful that your server handles this correctly - some servers are set up to return an error page without a 404 error.

3

recenty the picture is still in my couputer ,so for i can’t get the right result lol. so WWW.error ==null means no problem . when i use www.error !=null. seams it didn’t work too ,srange