feat(nfc): 添加flutter_nfc_kit支持并优化NFC认证流程

实现NFC卡片认证功能，替换原有nfc_manager实现
添加卡片录入界面和认证对话框
优化Android原生NFC处理逻辑

Author: unDefFtr

android/app/build.gradle.kts

@@ -24,7 +24,7 @@ android {
         applicationId = "com.example.classaware"
         // You can update the following values to match your application needs.
         // For more information, see: https://flutter.dev/to/review-gradle-config.
-        minSdk = flutter.minSdkVersion
+        minSdk = 26
         targetSdk = flutter.targetSdkVersion
         versionCode = flutter.versionCode
         versionName = flutter.versionName
@@ -42,3 +42,8 @@ android {
 flutter {
     source = "../.."
 }
+
+dependencies {
+    implementation("androidx.activity:activity:1.9.2")
+    implementation("androidx.activity:activity-ktx:1.9.2")
+}

android/app/src/main/kotlin/com/example/classaware/MainActivity.kt

@@ -3,6 +3,8 @@ package com.example.classaware
 import android.content.ComponentName
 import android.content.Context
 import android.content.Intent
+import android.app.PendingIntent
+import android.nfc.NfcAdapter
 import android.content.pm.LauncherApps
 import android.content.pm.PackageManager
 import android.content.pm.ResolveInfo
@@ -17,6 +19,7 @@ import io.flutter.embedding.android.FlutterActivity
 import io.flutter.embedding.engine.FlutterEngine
 import io.flutter.plugin.common.MethodChannel
 import java.io.ByteArrayOutputStream
+import im.nfc.flutter_nfc_kit.FlutterNfcKitPlugin
 
 class MainActivity : FlutterActivity() {
     private val CHANNEL = "com.example.classaware/launcher"
@@ -38,12 +41,52 @@ class MainActivity : FlutterActivity() {
                         result.error("ERROR", "Failed to get launchable apps", e.message)
                     }
                 }
+                "getAppIcon" -> {
+                    try {
+                        val packageName = call.argument<String>("packageName")
+                        if (packageName.isNullOrEmpty()) {
+                            result.error("ERROR", "Missing packageName", null)
+                        } else {
+                            Thread {
+                                try {
+                                    val bytes = getApplicationIconBytes(packageName)
+                                    runOnUiThread { result.success(bytes) }
+                                } catch (e: Exception) {
+                                    runOnUiThread { result.error("ERROR", "Failed to get app icon", e.message) }
+                                }
+                            }.start()
+                        }
+                    } catch (e: Exception) {
+                        result.error("ERROR", "Failed to get app icon", e.message)
+                    }
+                }
                 else -> {
                     result.notImplemented()
                 }
             }
         }
     }
+
+    override fun onResume() {
+        super.onResume()
+        val adapter: NfcAdapter? = NfcAdapter.getDefaultAdapter(this)
+        val pendingIntent: PendingIntent = PendingIntent.getActivity(
+            this, 0, Intent(this, javaClass).addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP), PendingIntent.FLAG_MUTABLE
+        )
+        adapter?.enableForegroundDispatch(this, pendingIntent, null, null)
+    }
+
+    override fun onPause() {
+        super.onPause()
+        val adapter: NfcAdapter? = NfcAdapter.getDefaultAdapter(this)
+        adapter?.disableForegroundDispatch(this)
+    }
+
+    override fun onNewIntent(intent: Intent) {
+        super.onNewIntent(intent)
+        val tag: android.nfc.Tag? = intent.getParcelableExtra(NfcAdapter.EXTRA_TAG)
+        tag?.apply(FlutterNfcKitPlugin::handleTag)
+    }
 
     // 使用LauncherApps服务获取应用 - 参考Lawnchair实现
     private fun getLaunchableAppsWithLauncherService(): List<Map<String, String>> {
@@ -70,17 +113,11 @@ class MainActivity : FlutterActivity() {
 
                         try {
                             val appName = activityInfo.label.toString()
-                            // 获取应用图标的Base64编码
-                            val iconBase64 = getAppIconBase64(componentName)
-                            
                             appList.add(mapOf(
                                 "name" to appName,
-                                "packageName" to packageName,
-                                "icon" to iconBase64
+                                "packageName" to packageName
                             ))
-                        } catch (e: Exception) {
-                            // 跳过无法获取信息的应用
-                        }
+                        } catch (_: Exception) {}
                     }
                 }
             } catch (e: Exception) {
@@ -91,19 +128,21 @@ class MainActivity : FlutterActivity() {
         return appList.sortedBy { it["name"] }
     }
 
-    /**
-     * 获取应用图标的Base64编码
-     */
-    private fun getAppIconBase64(componentName: ComponentName): String {
+    private fun getApplicationIconBytes(packageName: String): ByteArray? {
         return try {
-            val packageManager = packageManager
-            val drawable = packageManager.getActivityIcon(componentName)
-            val bitmap = drawableToBitmap(drawable)
+            val pm = packageManager
+            val drawable = pm.getApplicationIcon(packageName)
+            val src = drawableToBitmap(drawable)
+            val density = resources.displayMetrics.density
+            val sizePx = (48 * density).toInt().coerceAtLeast(32)
+            val bmp = if (src.width != sizePx || src.height != sizePx) {
+                Bitmap.createScaledBitmap(src, sizePx, sizePx, true)
+            } else src
             val outputStream = ByteArrayOutputStream()
-            bitmap.compress(Bitmap.CompressFormat.PNG, 100, outputStream)
-            Base64.encodeToString(outputStream.toByteArray(), Base64.NO_WRAP)
-        } catch (e: Exception) {
-            "" // 返回空字符串表示无图标
+            bmp.compress(Bitmap.CompressFormat.PNG, 80, outputStream)
+            outputStream.toByteArray()
+        } catch (_: Exception) {
+            null
         }
     }
 

android/build.gradle.kts

@@ -19,6 +19,18 @@ subprojects {
     project.evaluationDependsOn(":app")
 }
 
+// Force a single version of androidx.activity to avoid duplicate R classes
+subprojects {
+    configurations.all {
+        resolutionStrategy {
+            force(
+                "androidx.activity:activity:1.9.2",
+                "androidx.activity:activity-ktx:1.9.2"
+            )
+        }
+    }
+}
+
 tasks.register<Delete>("clean") {
     delete(rootProject.layout.buildDirectory)
 }

lib/main.dart

@@ -7,6 +7,8 @@ import 'screens/schedule_screen.dart';
 import 'screens/settings_screen.dart';
 import 'package:shared_preferences/shared_preferences.dart';
 import 'services/auth_service.dart';
+import 'package:flutter_nfc_kit/flutter_nfc_kit.dart';
+import 'dart:async';
 
 // 页面缓存包装器，防止页面重复构建
 class AutomaticKeepAliveWrapper extends StatefulWidget {
@@ -93,6 +95,7 @@ class _MainScreenState extends State<MainScreen> with TickerProviderStateMixin {
   final _selectIndex = ValueNotifier(0);
   bool _switchingPage = false;
   late final VoidCallback _authListener;
+  StreamSubscription? _nfcSub;
 
   final List<Widget> _screens = const [
     HomeScreen(),
@@ -109,13 +112,15 @@ class _MainScreenState extends State<MainScreen> with TickerProviderStateMixin {
     _pageController = PageController(initialPage: _selectIndex.value);
     _authListener = _onAuthActiveChanged;
     AuthService.instance.authActive.addListener(_authListener);
+    _setupNfcEvents();
   }
 
   @override
   void dispose() {
     _pageController.dispose();
     _selectIndex.dispose();
     AuthService.instance.authActive.removeListener(_authListener);
+    _nfcSub?.cancel();
     super.dispose();
   }
 
@@ -282,4 +287,19 @@ class _MainScreenState extends State<MainScreen> with TickerProviderStateMixin {
       ),
     );
   }
+  Future<void> _setupNfcEvents() async {
+    final prefs = await SharedPreferences.getInstance();
+    final allowNfc = prefs.getBool('auth_use_nfc') ?? false;
+    final uids = prefs.getStringList('auth_nfc_uids') ?? const [];
+    if (!allowNfc || uids.isEmpty) return;
+    _nfcSub = FlutterNfcKit.tagStream.listen((tag) async {
+      final id = (tag.id ?? '').trim();
+      if (id.isEmpty) return;
+      final prefs2 = await SharedPreferences.getInstance();
+      final wl = prefs2.getStringList('auth_nfc_uids') ?? const [];
+      if (wl.map((e) => e.toLowerCase()).contains(id.toLowerCase())) {
+        await AuthService.instance.grantAdminSession();
+      }
+    });
+  }
 }

lib/screens/apps_screen.dart

@@ -4,6 +4,7 @@ import 'package:url_launcher/url_launcher.dart';
 import '../services/auth_service.dart';
 import 'package:installed_apps/installed_apps.dart';
 import 'package:flutter/services.dart';
+import 'package:flutter/foundation.dart';
 import 'dart:convert';
 import '../utils/logger.dart';
 
@@ -25,6 +26,8 @@ class _AppsScreenState extends State<AppsScreen> with AutomaticKeepAliveClientMi
 
   // MethodChannel for native Android communication
   static const platform = MethodChannel('com.example.classaware/launcher');
+  final Map<String, Uint8List?> _iconCache = {};
+  final Map<String, Future<Uint8List?>> _iconFutures = {};
 
   @override
   bool get wantKeepAlive => true; // 保持页面状态，避免重复加载应用列表
@@ -68,8 +71,12 @@ class _AppsScreenState extends State<AppsScreen> with AutomaticKeepAliveClientMi
 
       for (var appData in launchableApps) {
         final Map<String, dynamic> app = Map<String, dynamic>.from(appData);
-        
-        // 原生Android代码已经包含图标数据
+        final iconStr = (app['icon'] ?? '').toString();
+        if (iconStr.isNotEmpty) {
+          try {
+            app['iconBytes'] = base64Decode(iconStr);
+          } catch (_) {}
+        }
         apps.add(app);
       }
 
@@ -238,9 +245,12 @@ class _AppsScreenState extends State<AppsScreen> with AutomaticKeepAliveClientMi
         SizedBox(height: 12.h),
         Expanded(
           child: ListView.builder(
+            cacheExtent: 200,
             itemCount: quickApps.length,
             itemBuilder: (context, index) {
               final app = quickApps[index];
+              final dpr = MediaQuery.of(context).devicePixelRatio;
+              final cacheSize = (48.w * dpr).round();
               return RepaintBoundary( // 添加重绘边界优化
                 child: GestureDetector(
                   onTap: () => _launchApp(app),
@@ -257,27 +267,7 @@ class _AppsScreenState extends State<AppsScreen> with AutomaticKeepAliveClientMi
                           ),
                           child: ClipRRect(
                             borderRadius: BorderRadius.circular(12.r),
-                            child: app['icon'] != null && app['icon'].toString().isNotEmpty
-                                ? Image.memory(
-                                    base64Decode(app['icon']),
-                                    width: 48.w,
-                                    height: 48.w,
-                                    fit: BoxFit.contain,
-                                    cacheWidth: (48.w * MediaQuery.of(context).devicePixelRatio).round(),
-                                    cacheHeight: (48.w * MediaQuery.of(context).devicePixelRatio).round(),
-                                    errorBuilder: (context, error, stackTrace) {
-                                      return Icon(
-                                        Icons.apps,
-                                        size: 24.sp,
-                                        color: Theme.of(context).colorScheme.onSurfaceVariant,
-                                      );
-                                    },
-                                  )
-                                : Icon(
-                                    Icons.apps,
-                                    size: 24.sp,
-                                    color: Theme.of(context).colorScheme.onSurfaceVariant,
-                                  ),
+                            child: _buildAppIcon(app['packageName'] as String, 48.w, cacheSize, fallbackColor: Theme.of(context).colorScheme.onSurfaceVariant, fallbackSize: 24.sp),
                           ),
                         ),
                         SizedBox(height: 4.h),
@@ -402,9 +392,12 @@ class _AppsScreenState extends State<AppsScreen> with AutomaticKeepAliveClientMi
                 final textHeight = fontSize * 1.2 * 2;
                 final tileHeight = iconSize + 4.h + textHeight + 12.0;
                 final aspect = (minTile / tileHeight).clamp(0.65, 1.0);
+                final dpr = MediaQuery.of(context).devicePixelRatio;
+                final cacheSize = (iconSize * dpr).round();
                 return GridView.builder(
                   physics: const BouncingScrollPhysics(),
                   shrinkWrap: true,
+                  cacheExtent: tileHeight * 2,
                   gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(
                     crossAxisCount: cols,
                     childAspectRatio: aspect,
@@ -434,27 +427,7 @@ class _AppsScreenState extends State<AppsScreen> with AutomaticKeepAliveClientMi
                                   ),
                                   child: ClipRRect(
                                     borderRadius: BorderRadius.circular(12.r),
-                                    child: app['icon'] != null && app['icon'].toString().isNotEmpty
-                                        ? Image.memory(
-                                            base64Decode(app['icon']),
-                                            width: 48.w,
-                                            height: 48.w,
-                                            fit: BoxFit.contain,
-                                            cacheWidth: (48.w * MediaQuery.of(context).devicePixelRatio).round(),
-                                            cacheHeight: (48.w * MediaQuery.of(context).devicePixelRatio).round(),
-                                            errorBuilder: (context, error, stackTrace) {
-                                              return Icon(
-                                                Icons.apps,
-                                                color: Theme.of(context).colorScheme.primary,
-                                                size: 28.w,
-                                              );
-                                            },
-                                          )
-                                        : Icon(
-                                            Icons.apps,
-                                            color: Theme.of(context).colorScheme.primary,
-                                            size: 28.w,
-                                          ),
+                                    child: _buildAppIcon(app['packageName'] as String, 48.w, cacheSize, fallbackColor: Theme.of(context).colorScheme.primary, fallbackSize: 28.w),
                                   ),
                                 ),
                                 SizedBox(height: 4.h),
@@ -499,4 +472,58 @@ class _AppsScreenState extends State<AppsScreen> with AutomaticKeepAliveClientMi
       return false;
     }
   }
+
+  Widget _buildAppIcon(String packageName, double size, int cacheSize, {required Color fallbackColor, required double fallbackSize}) {
+    final cached = _iconCache[packageName];
+    if (cached != null && cached.isNotEmpty) {
+      return Image.memory(
+        cached,
+        width: size,
+        height: size,
+        fit: BoxFit.contain,
+        cacheWidth: cacheSize,
+        cacheHeight: cacheSize,
+        filterQuality: FilterQuality.none,
+        gaplessPlayback: true,
+      );
+    }
+    final future = _iconFutures[packageName] ?? _requestIcon(packageName);
+    _iconFutures[packageName] = future;
+    return FutureBuilder<Uint8List?>(
+      future: future,
+      builder: (context, snap) {
+        if (snap.connectionState == ConnectionState.done && snap.data != null && snap.data!.isNotEmpty) {
+          return Image.memory(
+            snap.data!,
+            width: size,
+            height: size,
+            fit: BoxFit.contain,
+            cacheWidth: cacheSize,
+            cacheHeight: cacheSize,
+            filterQuality: FilterQuality.none,
+            gaplessPlayback: true,
+          );
+        }
+        return Icon(
+          Icons.apps,
+          color: fallbackColor,
+          size: fallbackSize,
+        );
+      },
+    );
+  }
+
+  Future<Uint8List?> _requestIcon(String packageName) async {
+    try {
+      final bytes = await platform.invokeMethod<Uint8List>('getAppIcon', {
+        'packageName': packageName,
+      });
+      if (bytes == null || bytes.isEmpty) return null;
+      _iconCache[packageName] = bytes;
+      return bytes;
+    } catch (_) {
+      _iconCache[packageName] = null;
+      return null;
+    }
+  }
 }