Question

im new to android development so please forgive me if this is an easy thing to do.

i want to get all the files in a directory on the sd card and display them in a spinner, but i just cant work out how.
this is what i have and i dont even know if any of it is any good.

//creates this directory if its not there??     
File sd = new File("/sdcard/myfolder");

                 //gets a list of the files
                 File[] sdDirList = sd.listFiles(); 

                 //add them to the spinner array (this makes it crash)
                 for(int i=0;i<sdDirList.length;i++) 
                 array_spinnerLoad[i] = sdDirList[i].getName();

so where am i going wrong?
any usefull link to an easy to use tutorial anywhere?
it doesnt have to be a spinner, just some list i can select from

thank you 🙂

edit:
it doesnt crash with this but the spinner array is not filled

File[] sdDirList = sd.listFiles(); 
             if (sdDirList != null)
             {
                 array_spinnerLoad=new String[sdDirList.length];

             for(int i=0;i<sdDirList.length;i++)

             array_spinnerLoad[i] = sdDirList[i].getName();
         }

Answer 1

If /sdcard/myfolder doesn’t exist or is not a directory, then listFiles returns null. You’re probably crashing with a NPE. You can use exists() and isDirectory() to diagnose what’s wrong. (Plus, you can test that sdDirList != null.)

P.S. It would help you to get more accurate answers to post details about the crash — such as the exception.