更新安装apk前申请安装权限

lib/dialog/app_update_dialog.dart

@@ -6,11 +6,11 @@ import 'package:eitc_erm_dental_flutter/funcs.dart';
 import 'package:eitc_erm_dental_flutter/widget/custom_divider.dart';
 import 'package:eitc_erm_dental_flutter/widget/main_button.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter/services.dart';
 import 'package:flutter_screenutil/flutter_screenutil.dart';
 import 'package:package_info_plus/package_info_plus.dart';
 import 'package:path_provider/path_provider.dart';
 import 'package:percent_indicator/percent_indicator.dart' as pi;
+import 'package:permission_handler/permission_handler.dart';
 
 import '../global.dart';
 import '../http/http.dart';
@@ -282,7 +282,14 @@ class _AppUpdateDialogState extends State<AppUpdateDialog> {
   }
 
   ///安装apk
-  void _installApk() {
+  void _installApk() async {
+    if (!await Permission.requestInstallPackages.isGranted) {
+      logd("app更新,没有安装apk权限,进行申请");
+      if (!await Permission.requestInstallPackages.request().isGranted) {
+        logd("app更新,申请安装apk权限被拒绝,终止安装");
+        return;
+      }
+    }
     logd("app更新,安装apk,path=$_filePath");
     AppInstaller.installApk(_filePath);
   }