add single_asset

example/lib/main.dart

                 text: "photo",
                 onTap: () => _pickAsset(PickType.onlyImage),
               ),
+              IconTextButton(
+                icon: Icons.photo,
+                text: "single photo",
+                onTap: () => _pickAsset(PickType.onlyImage, single: true),
+              ),
               IconTextButton(
                 icon: Icons.videocam,
                 text: "video",
     _pickAsset(PickType.all, pathList: assetPathList);
   }
 
-  void _pickAsset(PickType type, {List<AssetPathEntity> pathList}) async {
+  void _pickAsset(PickType type, {List<AssetPathEntity> pathList, bool single = false}) async {
     /// context is required, other params is optional.
     /// context is required, other params is optional.
     /// context is required, other params is optional.
     List<AssetPathEntity> pathList2 = await PhotoManager.getAssetPathList(
         hasAll: true, type: RequestType.image,);
-    PickedEntity entity = await PhotoPicker.pickAsset(
+        if (!single) {
+          PickedEntity entity = await PhotoPicker.pickAsset(
       context: context,
       padding: 4.0,
       itemRadio: 1,
-      maxSelected: 2,
+      maxSelected: 9,
       provider: I18nProvider.english,
       rowCount: 4,
       thumbSize: 150,
       sortDelegate: SortDelegate.common,
-      pickType: PickType.onlyVideo,
+      pickType: type,
       photoPathList: pathList2,
     );
 
       Navigator.push(context,
           MaterialPageRoute(builder: (_) => PreviewPage(list: preview)));
     }
+        } else {
+          final AssetEntity asset = await PhotoPicker.pickSingleAsset(
+            context: context,
+            padding: 4.0,
+            itemRadio: 1,
+            provider: I18nProvider.english,
+            rowCount: 4,
+            thumbSize: 150,
+            sortDelegate: SortDelegate.common,
+            pickType: type,
+            photoPathList: pathList2,
+          );
+          print(asset);
+        }
+    
     setState(() {});
   }
 

lib/photo.dart

     List<AssetPathEntity> photoPathList,
     List<AssetEntity> pickedAssetList,
   }) {
+    assert(maxSelected != 0, "maxSelected must be not 0");
     assert(provider != null, "provider must be not null");
     assert(context != null, "context must be not null");
     assert(pickType != null, "pickType must be not null");
     );
   }
 
+
+  static Future<AssetEntity> pickSingleAsset({
+    @required BuildContext context,
+    int rowCount = 4,
+    double padding = 1,
+    double itemRadio = 1.0,
+    int thumbSize = 180,
+    PhotoTheme theme,
+    I18nProvider provider = I18nProvider.chinese,
+    SortDelegate sortDelegate,
+    LoadingDelegate loadingDelegate,
+    PickType pickType = PickType.all,
+    List<AssetPathEntity> photoPathList,
+  }) async {
+    final PickedEntity result = await PhotoPicker.pickAsset(
+      context: context,
+      rowCount: rowCount,
+      maxSelected: 1,
+      padding: padding,
+      itemRadio: itemRadio,
+      thumbSize: thumbSize,
+      theme: theme,
+      provider: provider,
+      sortDelegate: sortDelegate,
+      loadingDelegate: loadingDelegate,
+      pickType: pickType,
+      photoPathList: photoPathList,
+      pickedAssetList: [],
+    );
+    if (result.asset.isNotEmpty) {
+      return result.asset[0];
+    }
+    return null;
+  }
+
   static Future<File> pickCamera({
     double maxWidth,
     double maxHeight,

lib/src/ui/page/photo_main_page.dart

           ),
         ),
         body: _buildBody(),
-        bottomNavigationBar: _BottomWidget(
+        bottomNavigationBar: options.maxSelected > 1 ? _BottomWidget(
           key: scaffoldKey,
           provider: i18nProvider,
           options: options,
           onTapSure: selectedList.isEmpty ? null : sure,
           selectedProvider: this,
           galleryListProvider: this,
-        ),
+        ) : null,
       ),
     );
   }
               loadingDelegate: options.loadingDelegate,
               badgeDelegate: options.badgeDelegate,
             ),
+            if (options.maxSelected > 1)
             _buildMask(containsEntity(data)),
+            if (options.maxSelected > 1)
             _buildSelected(data),
           ],
         ),
   }
 
   void _onItemClick(AssetEntity data, int index) {
+    if (options.maxSelected == 1) {
+      widget.onClose?.call(PickedEntity(
+        asset: [data],
+        isFullImage: true,
+      ));
+      return;
+    }
     var result = PhotoPreviewResult();
     isPushed = true;
     Navigator.of(context).push(

pubspec.lock

       name: flutter_plugin_android_lifecycle
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "1.0.7"
+    version: "1.0.8"
   flutter_test:
     dependency: "direct dev"
     description: flutter
     source: sdk
     version: "0.0.0"
+  http:
+    dependency: transitive
+    description:
+      name: http
+      url: "https://pub.flutter-io.cn"
+    source: hosted
+    version: "0.12.1"
+  http_parser:
+    dependency: transitive
+    description:
+      name: http_parser
+      url: "https://pub.flutter-io.cn"
+    source: hosted
+    version: "3.1.4"
   image_picker:
     dependency: "direct main"
     description:
       name: image_picker
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "0.6.6+1"
+    version: "0.6.7"
   image_picker_platform_interface:
     dependency: transitive
     description:
       name: image_picker_platform_interface
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "1.0.0"
+    version: "1.1.0"
   matcher:
     dependency: transitive
     description:
       url: "https://pub.flutter-io.cn"
     source: hosted
     version: "1.7.0"
+  pedantic:
+    dependency: transitive
+    description:
+      name: pedantic
+      url: "https://pub.flutter-io.cn"
+    source: hosted
+    version: "1.9.0"
   photo_manager:
     dependency: "direct main"
     description:
       name: provider
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "4.0.5"
+    version: "4.1.2"
   sky_engine:
     dependency: transitive
     description: flutter
     version: "2.0.8"
 sdks:
   dart: ">=2.7.0 <3.0.0"
-  flutter: ">=1.12.13 <2.0.0"
+  flutter: ">=1.16.0 <2.0.0"

pubspec.yaml

 name: photo
 description: image picker, multi picker support video/icloud asset, use flutter as ui, if you want to build custom ui, you just use photo_manager.
-version: 0.5.1
+version: 0.5.2
 author: caijinglong<cjl_spy@163.com>
 homepage: https://github.com/CaiJingLong/flutter_photo