fix bug:android emulator

android/app/src/main/AndroidManifest.xml

@@ -6,6 +6,8 @@
          to allow setting breakpoints, to provide hot reload, etc.
     -->
     <uses-permission android:name="android.permission.INTERNET"/>
+    <uses-permission android:name="android.permission.MODE_WORLD_READABLE"/>
+    <uses-permission android:name="android.permission.MODE_WORLD_WRITEABLE"/>
 
     <!-- io.flutter.app.FlutterApplication is an android.app.Application that
          calls FlutterMain.startInitialization(this); in its onCreate method.

lib/common/provider.dart

@@ -11,27 +11,38 @@ class Provider {
   //初始化数据库
   // isCreate 用永远 copy 一个新的数据库
   Future init(bool isCreate) async {
+    //Get a location using getDatabasesPath
     String databasesPath = await getDatabasesPath();
     String path = join(databasesPath, 'flutter.db');
-    try {
-      db = await openDatabase(path);
-    } catch (e) {
-      print("Error $e");
-    }
-    if (isCreate) {
+    List<Map> list;
+    // try {
+    //   db = await openDatabase(path, readOnly: true);
+
+    // } catch (e) {
+    //   print("Error $e");
+    // }
+
+    if (db == null) {
+      // Delete the database
+      await deleteDatabase(path);
+
       ByteData data = await rootBundle.load(join("assets", "app.db"));
       List<int> bytes =
           data.buffer.asUint8List(data.offsetInBytes, data.lengthInBytes);
       await new File(path).writeAsBytes(bytes);
 
-      db = await openDatabase(path, version: 2,
-          onCreate: (Database db, int version) async {
-        print('db created version is $version');
-      }, onOpen: (Database db) async {
-        print('new db opened');
-      });
+      // db = await openDatabase(path, version: 2,
+      //     onCreate: (Database db, int version) async {
+      //   print('db created version is $version');
+      // }, onOpen: (Database db) async {
+      //   print('new db opened');
+      // });
+      db = await openDatabase(path, readOnly: true);
+            list = await db
+          .rawQuery('SELECT name FROM sqlite_master WHERE type = "table"');
+      print('$list 1234567891');
     } else {
-      // print('Opening existing database');
+      print("Opening existing database");
     }
   }
 }

lib/views/widgetPage/cate_card.dart

@@ -28,7 +28,7 @@ class _CateCardState extends State<CateCard> {
     Cat childCateCondition = new Cat(parentId: parentId);
 
     List<Cat> list = await catControl.getList(childCateCondition);
-    if (list.isNotEmpty&&list.length>=1) {
+    if (list.isNotEmpty&&list.length>=1 && this.mounted) {
       setState(() {
         _firstChildList = list;
       });

pubspec.yaml

@@ -47,6 +47,7 @@ flutter:
   assets:
     - assets/app.db
     - assets/images/
+
   # To add assets to your application, add an assets section, like this:
   # assets:
   #  - images/a_dot_burr.jpeg