FILEOPENPICKER
▪ var imageFile,
picker = new Windows.Storage.Pickers.FileOpenPicker();
picker.fileTypeFilter.replaceAll([".jpg", ".bmp", ".gif", ".png"]);
picker.viewMode = Windows.Storage.Pickers.PickerViewMode.thumbnail;
picker.pickSingleFileAsync().done(function (file) {
if (file)
imageFile = file;
});
/* picker.pickMultipleFileAsync().done(function (files) { }); */