Pass your app context to the static method.
public static List <String> fromSDCard(Context context)
{
List <String> listChurchWall = new ArrayList <String>();
// listing Wallpaper using church names
String string = "/mnt/sdcard/Church/Wallpaper/";
f = new File (string+name+"/");
if (f.exists())
{
files = f.listFiles ();
}else{
// 1. Instantiate an AlertDialog.Builder with its constructor
AlertDialog.Builder builder = new AlertDialog.Builder(context);
// 2. Chain together various setter methods to set the dialog characteristics
builder.setMessage(R.string.dialog_message)
.setTitle(R.string.dialog_title);
// 3. Get the AlertDialog from create()
AlertDialog dialog = builder.create();
// 4. Show the dialog
dialog.show()
}
return listChurchWall;
}
If calling from your activity.
public MyActivity extends Activity
{
....
private void Method()
{
List<String> list = fromSdCard(this);
}
....
}