feat: 新增添加背景图片设置项

Author: Xwei1645

lib/main.dart

@@ -1,5 +1,5 @@
 import 'dart:async';
-import 'dart:io' show Platform;
+import 'dart:io' show Platform, File;
 import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_localizations/flutter_localizations.dart';
@@ -181,6 +181,10 @@ class _HomeworkBoardState extends State<HomeworkBoard> with WindowListener, Tick
   // 背景不透明度
   double _backgroundOpacity = 1.0;
 
+  // 背景图片相关
+  String? _backgroundImagePath;
+  int _backgroundImageMode = 0;
+  
   // 快捷菜单动画控制器
   late AnimationController _quickMenuAnimationController;
   late Animation<double> _quickMenuOpacityAnimation;
@@ -299,6 +303,8 @@ class _HomeworkBoardState extends State<HomeworkBoard> with WindowListener, Tick
     final settingsService = SettingsService.instance;
     setState(() {
       _backgroundOpacity = settingsService.getBackgroundOpacity();
+      _backgroundImagePath = settingsService.getBackgroundImagePath();
+      _backgroundImageMode = settingsService.getBackgroundImageMode();
     });
   }
 
@@ -669,6 +675,13 @@ class _HomeworkBoardState extends State<HomeworkBoard> with WindowListener, Tick
                 color: _isFullScreen 
                     ? Theme.of(context).colorScheme.surface
                     : Theme.of(context).colorScheme.surface.withValues(alpha: _backgroundOpacity),
+                image: _backgroundImagePath != null && _backgroundImagePath!.isNotEmpty
+                    ? DecorationImage(
+                        image: FileImage(File(_backgroundImagePath!)),
+                        fit: _getBoxFitFromMode(_backgroundImageMode),
+                        opacity: 0.3, // 半透明显示
+                      )
+                    : null,
                 borderRadius: _isFullScreen 
                     ? BorderRadius.zero 
                     : BorderRadius.circular(12),
@@ -1429,4 +1442,17 @@ class _HomeworkBoardState extends State<HomeworkBoard> with WindowListener, Tick
       // 保存失败，静默处理
     }
   }
+
+  BoxFit _getBoxFitFromMode(int mode) {
+    switch (mode) {
+      case 0:
+        return BoxFit.contain; // 适应
+      case 1:
+        return BoxFit.cover; // 填充
+      case 2:
+        return BoxFit.fill; // 拉伸
+      default:
+        return BoxFit.contain;
+    }
+  }
 }

lib/models/app_config.dart

@@ -10,6 +10,8 @@ class AppConfig {
   final bool firstLaunch; // 是否首次启动
   final bool showInTaskbar; // 是否在任务栏显示
   final int? themeColor; // 自定义主题色，null表示使用默认色
+  final String? backgroundImagePath; // 背景图片路径
+  final int backgroundImageMode; // 背景图片显示模式: 0=适应, 1=填充, 2=拉伸
 
   const AppConfig({
     this.theme = 'light',
@@ -23,6 +25,8 @@ class AppConfig {
     this.firstLaunch = true,
     this.showInTaskbar = false,
     this.themeColor,
+    this.backgroundImagePath,
+    this.backgroundImageMode = 0,
   });
 
   AppConfig copyWith({
@@ -37,6 +41,8 @@ class AppConfig {
     bool? firstLaunch,
     bool? showInTaskbar,
     int? themeColor,
+    String? backgroundImagePath,
+    int? backgroundImageMode,
   }) {
     return AppConfig(
       theme: theme ?? this.theme,
@@ -50,6 +56,8 @@ class AppConfig {
       firstLaunch: firstLaunch ?? this.firstLaunch,
       showInTaskbar: showInTaskbar ?? this.showInTaskbar,
       themeColor: themeColor ?? this.themeColor,
+      backgroundImagePath: backgroundImagePath ?? this.backgroundImagePath,
+      backgroundImageMode: backgroundImageMode ?? this.backgroundImageMode,
     );
   }
 
@@ -67,6 +75,8 @@ class AppConfig {
       'firstLaunch': firstLaunch,
       'showInTaskbar': showInTaskbar,
       'themeColor': themeColor,
+      'backgroundImagePath': backgroundImagePath,
+      'backgroundImageMode': backgroundImageMode,
     };
   }
 
@@ -84,6 +94,8 @@ class AppConfig {
       firstLaunch: json['firstLaunch'] as bool? ?? true,
       showInTaskbar: json['showInTaskbar'] as bool? ?? false,
       themeColor: json['themeColor'] as int?,
+      backgroundImagePath: json['backgroundImagePath'] as String?,
+      backgroundImageMode: json['backgroundImageMode'] as int? ?? 0,
     );
   }
 }

lib/services/settings_service.dart

@@ -438,4 +438,48 @@ class SettingsService {
     }
   }
 
+  /// 获取背景图片路径
+  String? getBackgroundImagePath() {
+    final config = JsonStorageService.instance.getAppConfig();
+    return config.backgroundImagePath;
+  }
+
+  /// 设置背景图片路径
+  Future<bool> setBackgroundImagePath(String? path) async {
+    try {
+      // 更新JSON配置
+      final storageService = JsonStorageService.instance;
+      final currentConfig = storageService.getAppConfig();
+      final updatedConfig = currentConfig.copyWith(
+        backgroundImagePath: path,
+      );
+      await storageService.saveAppConfig(updatedConfig);
+      return true;
+    } catch (e) {
+      return false;
+    }
+  }
+
+  /// 获取背景图片显示模式
+  int getBackgroundImageMode() {
+    final config = JsonStorageService.instance.getAppConfig();
+    return config.backgroundImageMode;
+  }
+
+  /// 设置背景图片显示模式: 0=适应, 1=填充, 2=拉伸
+  Future<bool> setBackgroundImageMode(int mode) async {
+    try {
+      // 更新JSON配置
+      final storageService = JsonStorageService.instance;
+      final currentConfig = storageService.getAppConfig();
+      final updatedConfig = currentConfig.copyWith(
+        backgroundImageMode: mode,
+      );
+      await storageService.saveAppConfig(updatedConfig);
+      return true;
+    } catch (e) {
+      return false;
+    }
+  }
+
 }