Added pickDirectory implementation for Windows

README.md

@@ -36,7 +36,7 @@ See [this](./install-old.md)
 
 ## API
 
-#### [Android only] `DocumentPicker.pickDirectory()`
+#### [Android and Windows only] `DocumentPicker.pickDirectory()`
 
 Open a system directory picker. Returns a promise that resolves to (`{ uri: string }`) of the directory selected by user.
 
@@ -66,7 +66,7 @@ If specified, the picked file is copied to `NSCachesDirectory` / `NSDocumentDire
 
 This should help if you need to work with the file(s) later on, because by default, [the picked documents are temporary files. They remain available only until your application terminates](https://developer.apple.com/documentation/uikit/uidocumentpickerdelegate/2902364-documentpicker). This may impact performance for large files, so keep this in mind if you expect users to pick particularly large files and your app does not need immediate read access.
 
-##### [UWP only] `readContent`:`boolean`
+##### [Windows only] `readContent`:`boolean`
 
 Defaults to `false`. If `readContent` is set to true the content of the picked file/files will be read and supplied in the result object.
 
@@ -107,7 +107,7 @@ The display name of the file. _This is normally the filename of the file, but An
 
 The file size of the document. _On Android some DocumentProviders may not provide this information for a document._
 
-##### [UWP only] `content`:
+##### [Windows only] `content`:
 
 The base64 encoded content of the picked file if the option `readContent` was set to `true`.
 

index.js

@@ -191,7 +191,7 @@ export default class DocumentPicker {
   }
 
   static pickDirectory() {
-    if (Platform.OS === 'android') {
+    if (Platform.OS === 'android' || Platform.OS === 'windows') {
       return RNDocumentPicker.pickDirectory();
     } else {
       return Promise.resolve(null);

windows/ReactNativeDocumentPicker/RCTDocumentPickerModule.cs

@@ -102,6 +102,32 @@ public async Task<List<JSValueObject>> Pick(JSValue options)
             return result;
         }
 
+        [ReactMethod("pickDirectory")]
+        public async Task<JSValueObject> PickDirectory()
+        {
+            TaskCompletionSource<JSValueObject> tcs = new TaskCompletionSource<JSValueObject>();
+
+            await CoreApplication.MainView.CoreWindow.Dispatcher.RunAsync(CoreDispatcherPriority.Normal, async () =>
+            {
+                var openFolderPicker = new FolderPicker();
+
+                openFolderPicker.ViewMode = PickerViewMode.List;
+                openFolderPicker.SuggestedStartLocation = PickerLocationId.DocumentsLibrary;
+                openFolderPicker.FileTypeFilter.Add("*");
+
+                var folder = await openFolderPicker.PickSingleFolderAsync();
+                JSValueObject obj = new JSValueObject
+                {
+                    { "uri", folder.Path }
+                };
+
+                tcs.SetResult(obj);
+            });
+
+            var result = await tcs.Task;
+            return result;
+        }
+
         private async Task<JSValueObject> PrepareFile(StorageFile file, bool cache, bool readContent)
         {
             string base64Content = null;