feat: 优化图片加载和展示功能

- 新增 SmartImage 组件优化图片加载体验
- 新增 ImageGrid 组件支持多图布局展示
- 新增 imageHelper 工具函数
- 优化 PostCard 帖子卡片图片展示
- 优化消息页面 SegmentRenderer
- 优化日程页面 ScheduleScreen
- 优化上传服务 uploadService

src/components/business/PostCard.tsx

@@ -20,6 +20,7 @@ import Avatar from '../common/Avatar';
 import { ImageGrid, ImageGridItem, SmartImage } from '../common';
 import VotePreview from './VotePreview';
 import { useResponsive, useResponsiveValue } from '../../hooks/useResponsive';
+import { getPreviewImageUrl, ImageDisplayMode } from '../../utils/imageHelper';
 
 interface PostCardProps {
   post: Post;
@@ -206,6 +207,8 @@ const PostCard: React.FC<PostCardProps> = ({
       id: img.id,
       url: img.url,
       thumbnail_url: img.thumbnail_url,
+      preview_url: img.preview_url,
+      preview_url_large: img.preview_url_large,
       width: img.width,
       height: img.height,
     }));
@@ -224,6 +227,8 @@ const PostCard: React.FC<PostCardProps> = ({
           borderRadius={imageBorderRadius}
           showMoreOverlay={true}
           onImagePress={onImagePress}
+          displayMode={variant === 'grid' ? 'grid' : 'list'}
+          usePreview={true}
         />
       </View>
     );
@@ -335,6 +340,11 @@ const PostCard: React.FC<PostCardProps> = ({
     const aspectRatios = [0.7, 0.75, 0.8, 0.85, 0.9, 1, 1.1, 1.2];
     const aspectRatio = aspectRatios[hash % aspectRatios.length];
 
+    // 获取封面图预览 URL
+    const coverUrl = hasImage
+      ? getPreviewImageUrl(coverImage, 'grid')
+      : '';
+
     // 获取正文预览（无图时显示）
     const getContentPreview = (content: string | undefined | null): string => {
       if (!content) return '';
@@ -369,9 +379,10 @@ const PostCard: React.FC<PostCardProps> = ({
             onPress={() => onImagePress?.(post.images || [], 0)}
           >
             <SmartImage
-              source={{ uri: coverImage.thumbnail_url || coverImage.url || '' }}
+              source={{ uri: coverUrl }}
               style={[styles.gridCoverImage, { aspectRatio }]}
               resizeMode="cover"
+              usePreview={true}
             />
           </TouchableOpacity>
         )}

src/components/common/ImageGrid.tsx

@@ -2,6 +2,7 @@
  * ImageGrid 图片网格组件
  * 支持 1-9 张图片的智能布局
  * 根据图片数量自动选择最佳展示方式
+ * 支持预览图优化
  */
 
 import React, { useMemo, useCallback, useState, useEffect } from 'react';
@@ -16,6 +17,7 @@ import {
 } from 'react-native';
 import { SmartImage, ImageSource } from './SmartImage';
 import { colors, spacing, borderRadius } from '../../theme';
+import { getPreviewImageUrl, ImageDisplayMode } from '../../utils/imageHelper';
 
 const { width: SCREEN_WIDTH } = Dimensions.get('window');
 
@@ -69,6 +71,10 @@ export interface ImageGridProps {
   onImagePress?: (images: ImageGridItem[], index: number) => void;
   /** 测试ID */
   testID?: string;
+  /** 显示模式 */
+  displayMode?: ImageDisplayMode;
+  /** 是否使用预览图 */
+  usePreview?: boolean;
 }
 
 /**
@@ -201,6 +207,7 @@ const SingleImageItem: React.FC<SingleImageItemProps> = ({
 /**
  * 图片网格组件
  * 智能布局：根据图片数量自动选择最佳展示方式
+ * 支持预览图优化
  */
 export const ImageGrid: React.FC<ImageGridProps> = ({
   images,
@@ -214,6 +221,8 @@ export const ImageGrid: React.FC<ImageGridProps> = ({
   gridColumns = 3,
   onImagePress,
   testID,
+  displayMode = 'list',
+  usePreview = true,
 }) => {
   // 通过 onLayout 拿到容器实际宽度
   const [containerWidth, setContainerWidth] = useState(0);
@@ -256,6 +265,12 @@ export const ImageGrid: React.FC<ImageGridProps> = ({
   const renderSingleImage = () => {
     const image = displayImages[0];
     if (!image) return null;
+    
+    // 获取预览图 URL
+    const previewUrl = usePreview && displayMode
+      ? getPreviewImageUrl(image as any, displayMode)
+      : (image.uri || image.url || '');
+    
     return (
       <SingleImageItem
         image={image}
@@ -271,27 +286,33 @@ export const ImageGrid: React.FC<ImageGridProps> = ({
   const renderHorizontal = () => {
     return (
       <View style={[styles.horizontalContainer, { gap }]}>
-        {displayImages.map((image, index) => (
+        {displayImages.map((image, index) => {
-          <Pressable
+          const previewUrl = usePreview && displayMode
-            key={image.id || index}
+            ? getPreviewImageUrl(image as any, displayMode)
-            onPress={() => handleImagePress(index)}
+            : (image.uri || image.url || '');
-            style={[
+          
-              styles.horizontalItem,
+          return (
-              {
+            <Pressable
-                flex: 1,
+              key={image.id || index}
-                aspectRatio: 1,
+              onPress={() => handleImagePress(index)}
-                borderRadius: borderRadiusValue,
+              style={[
-              },
+                styles.horizontalItem,
-            ]}
+                {
-          >
+                  flex: 1,
-            <SmartImage
+                  aspectRatio: 1,
-              source={{ uri: image.uri || image.url, width: image.width, height: image.height }}
+                  borderRadius: borderRadiusValue,
-              style={styles.fullSize}
+                },
-              resizeMode="cover"
+              ]}
-              borderRadius={borderRadiusValue}
+            >
-            />
+              <SmartImage
-          </Pressable>
+                source={{ uri: previewUrl }}
-        ))}
+                style={styles.fullSize}
+                resizeMode="cover"
+                borderRadius={borderRadiusValue}
+              />
+            </Pressable>
+          );
+        })}
       </View>
     );
   };
@@ -303,6 +324,10 @@ export const ImageGrid: React.FC<ImageGridProps> = ({
         {displayImages.map((image, index) => {
           const isLastVisible = index === displayImages.length - 1;
           const showOverlay = isLastVisible && remainingCount > 0 && showMoreOverlay;
+          
+          const previewUrl = usePreview && displayMode
+            ? getPreviewImageUrl(image as any, displayMode)
+            : (image.uri || image.url || '');
 
           return (
             <Pressable
@@ -317,7 +342,7 @@ export const ImageGrid: React.FC<ImageGridProps> = ({
               ]}
             >
               <SmartImage
-                source={{ uri: image.uri || image.url, width: image.width, height: image.height }}
+                source={{ uri: previewUrl }}
                 style={styles.fullSize}
                 resizeMode="cover"
                 borderRadius={borderRadiusValue}
@@ -361,6 +386,10 @@ export const ImageGrid: React.FC<ImageGridProps> = ({
               ? image.width / image.height
               : 1;
             const height = itemWidth / aspectRatio;
+            
+            const previewUrl = usePreview && displayMode
+              ? getPreviewImageUrl(image as any, displayMode)
+              : (image.uri || image.url || '');
 
             return (
               <Pressable
@@ -376,7 +405,7 @@ export const ImageGrid: React.FC<ImageGridProps> = ({
                 ]}
               >
                 <SmartImage
-                  source={{ uri: image.uri || image.url, width: image.width, height: image.height }}
+                  source={{ uri: previewUrl }}
                   style={styles.fullSize}
                   resizeMode="cover"
                   borderRadius={borderRadiusValue}

src/components/common/SmartImage.tsx

@@ -4,7 +4,7 @@
  * 基于 expo-image 封装，原生支持 GIF/WebP 动图
  */
 
-import React, { useState, useCallback, useRef } from 'react';
+import React, { useState, useCallback, useRef, useEffect } from 'react';
 import {
   View,
   StyleSheet,
@@ -55,6 +55,14 @@ export interface SmartImageProps {
   onError?: (error: any) => void;
   /** 测试ID */
   testID?: string;
+  /** 预览图 URL */
+  previewUrl?: string;
+  /** 是否使用预览图（优先加载预览图） */
+  usePreview?: boolean;
+  /** 是否懒加载 */
+  lazyLoad?: boolean;
+  /** 缓存策略 */
+  cachePolicy?: 'memory' | 'disk' | 'memory-disk' | 'none';
 }
 
 /**
@@ -74,14 +82,33 @@ export const SmartImage: React.FC<SmartImageProps> = ({
   onLoad,
   onError,
   testID,
+  previewUrl,
+  usePreview = false,
+  lazyLoad = false,
+  cachePolicy = 'memory-disk',
 }) => {
   const [loadState, setLoadState] = useState<ImageLoadState>('loading');
+  const [isVisible, setIsVisible] = useState(!lazyLoad);
+  const [shouldLoadOriginal, setShouldLoadOriginal] = useState(false);
 
   // 解析图片源 - 支持 uri 或 url 字段
-  const imageUri = typeof source === 'string' 
+  const imageUri = typeof source === 'string'
-    ? source 
+    ? source
     : (source.uri || source.url || '');
 
+  // 解析预览图 URL
+  const previewUri = typeof previewUrl === 'string' ? previewUrl : '';
+
+  // 智能选择图片 URL
+  const getImageUrl = useCallback((): string => {
+    // 如果应该加载原图（预览图已加载完成或没有预览图）
+    if (shouldLoadOriginal || !usePreview || !previewUri) {
+      return imageUri;
+    }
+    // 否则使用预览图
+    return previewUri;
+  }, [imageUri, previewUri, usePreview, shouldLoadOriginal]);
+
   // 处理加载开始
   const handleLoadStart = useCallback(() => {
     setLoadState('loading');
@@ -90,16 +117,25 @@ export const SmartImage: React.FC<SmartImageProps> = ({
   // 处理加载完成
   const handleLoad = useCallback(() => {
     setLoadState('success');
+    // 如果正在加载预览图，切换到原图
+    if (usePreview && !shouldLoadOriginal && previewUri && getImageUrl() === previewUri) {
+      setShouldLoadOriginal(true);
+    }
     onLoad?.();
-  }, [onLoad]);
+  }, [onLoad, usePreview, shouldLoadOriginal, previewUri, getImageUrl]);
 
   // 处理加载错误
   const handleError = useCallback(
     (error: any) => {
+      // 如果预览图加载失败，尝试加载原图
+      if (usePreview && !shouldLoadOriginal && getImageUrl() === previewUri && imageUri) {
+        setShouldLoadOriginal(true);
+        return;
+      }
       setLoadState('error');
       onError?.(error);
     },
-    [onError]
+    [onError, usePreview, shouldLoadOriginal, getImageUrl, previewUri, imageUri]
   );
 
   // 重试加载
@@ -144,7 +180,7 @@ export const SmartImage: React.FC<SmartImageProps> = ({
   };
 
   // 图片源配置
-  const imageSource = imageUri && imageUri.trim() !== '' ? { uri: imageUri } : undefined;
+  const imageSource = imageUri && imageUri.trim() !== '' ? { uri: getImageUrl() } : undefined;
 
   // 如果没有有效的图片源，显示错误占位
   if (!imageSource) {
@@ -164,6 +200,16 @@ export const SmartImage: React.FC<SmartImageProps> = ({
     );
   }
 
+  // 如果是懒加载且不可见，显示占位
+  if (lazyLoad && !isVisible) {
+    return (
+      <View
+        style={[containerStyle, style as ViewStyle, { backgroundColor: '#F5F5F5' }]}
+        testID={testID}
+      />
+    );
+  }
+
   return (
     <Pressable
       style={[containerStyle, style as ViewStyle]}
@@ -181,7 +227,7 @@ export const SmartImage: React.FC<SmartImageProps> = ({
           resizeMode === 'center' ? 'scale-down' :
           resizeMode
         }
-        cachePolicy="memory-disk"
+        cachePolicy={cachePolicy}
         onLoadStart={handleLoadStart}
         onLoad={handleLoad}
         onError={handleError}

src/screens/message/components/ChatScreen/SegmentRenderer.tsx

@@ -438,11 +438,20 @@ const renderLinkSegment = (
 ): React.ReactNode => {
   const { onLinkPress, isMe } = props;
   
-  const handlePress = () => {
+  const handlePress = async () => {
     if (onLinkPress) {
       onLinkPress(data.url);
     } else {
-      Linking.openURL(data.url).catch(() => {});
+      try {
+        const supported = await Linking.canOpenURL(data.url);
+        if (supported) {
+          await Linking.openURL(data.url);
+        } else {
+          console.warn('无法打开链接:', data.url);
+        }
+      } catch (error) {
+        console.warn('打开链接失败:', error);
+      }
     }
   };
   
@@ -466,7 +475,13 @@ const renderLinkSegment = (
           </Text>
         )}
         <Text style={styles.linkUrl} numberOfLines={1}>
-          {new URL(data.url).hostname}
+          {(() => {
+            try {
+              return new URL(data.url).hostname;
+            } catch {
+              return data.url;
+            }
+          })()}
         </Text>
       </View>
     </TouchableOpacity>

src/screens/schedule/ScheduleScreen.tsx

@@ -145,6 +145,8 @@ export const ScheduleScreen: React.FC = () => {
   const [startWeekInput, setStartWeekInput] = useState(String(currentWeek));
   const [endWeekInput, setEndWeekInput] = useState(String(TOTAL_WEEKS));
   const weekScrollRef = useRef<ScrollView | null>(null);
+  // 组件卸载状态标记，用于防止组件卸载后仍调用 setState
+  const isMountedRef = useRef(true);
 
   // 设置弹窗状态
   const [isSettingsModalVisible, setIsSettingsModalVisible] = useState(false);
@@ -153,6 +155,13 @@ export const ScheduleScreen: React.FC = () => {
   const [syncUsername, setSyncUsername] = useState('');
   const [syncPassword, setSyncPassword] = useState('');
   const [isSyncing, setIsSyncing] = useState(false);
+
+  // 组件卸载时设置标记
+  useEffect(() => {
+    return () => {
+      isMountedRef.current = false;
+    };
+  }, []);
   const todayColumnIndex = getTodayColumnIndex();
   // currentWeek === 1 对应今天所在的真实周（offset 0），其他周不高亮今日列
   const isViewingCurrentWeek = currentWeek === 1;
@@ -463,14 +472,31 @@ export const ScheduleScreen: React.FC = () => {
                 style: 'destructive' as const,
                 onPress: async () => {
                   try {
-                    // 删除所有相关课程
+                    // 使用 Promise.allSettled 批量删除，即使部分失败也能继续
-                    for (const relatedCourse of relatedCourses) {
+                    const results = await Promise.allSettled(
-                      await scheduleService.deleteCourse(relatedCourse.id);
+                      relatedCourses.map(course => scheduleService.deleteCourse(course.id))
+                    );
+                    
+                    // 统计成功和失败的数量
+                    const fulfilledCount = results.filter(r => r.status === 'fulfilled').length;
+                    const rejectedCount = results.filter(r => r.status === 'rejected').length;
+                    
+                    // 只移除成功删除的课程
+                    const successfullyDeletedIds = new Set(
+                      relatedCourses
+                        .filter((_, index) => results[index].status === 'fulfilled')
+                        .map(c => c.id)
+                    );
+                    setCourses(prev => prev.filter(c => !successfullyDeletedIds.has(c.id)));
+                    
+                    if (rejectedCount > 0) {
+                      Alert.alert(
+                        '部分删除成功',
+                        `成功删除 ${fulfilledCount} 节课程，${rejectedCount} 节删除失败，请重试`
+                      );
+                    } else {
+                      Alert.alert('成功', `已删除 ${fulfilledCount} 节课程`);
                     }
-                    // 从本地状态中移除
-                    const relatedIds = new Set(relatedCourses.map(c => c.id));
-                    setCourses(prev => prev.filter(c => !relatedIds.has(c.id)));
-                    Alert.alert('成功', `已删除 ${relatedCourses.length} 节课程`);
                   } catch (error) {
                     console.error('批量删除课程失败:', error);
                     Alert.alert('删除失败', '请稍后重试');
@@ -755,14 +781,17 @@ export const ScheduleScreen: React.FC = () => {
                 ]}
                 onPress={async () => {
                   if (!syncUsername.trim() || !syncPassword.trim()) return;
-
+  
                   setIsSyncing(true);
                   try {
                     const result = await scheduleService.syncSchedule({
                       username: syncUsername.trim(),
                       password: syncPassword.trim(),
                     });
-
+  
+                    // 检查组件是否已卸载
+                    if (!isMountedRef.current) return;
+  
                     if (result.success) {
                       Alert.alert(
                         '同步成功',
@@ -787,9 +816,15 @@ export const ScheduleScreen: React.FC = () => {
                     }
                   } catch (error) {
                     console.error('同步课表失败:', error);
-                    Alert.alert('同步失败', '网络错误，请稍后重试');
+                    // 检查组件是否已卸载
+                    if (isMountedRef.current) {
+                      Alert.alert('同步失败', '网络错误，请稍后重试');
+                    }
                   } finally {
-                    setIsSyncing(false);
+                    // 检查组件是否已卸载
+                    if (isMountedRef.current) {
+                      setIsSyncing(false);
+                    }
                   }
                 }}
                 activeOpacity={0.8}

src/services/uploadService.ts

@@ -35,6 +35,8 @@ function resolveFileInfo(uri: string, providedType?: string): { name: string; ty
 // 上传响应
 export interface UploadResponse {
   url: string;
+  preview_url?: string;       // 列表/网格预览图
+  preview_url_large?: string;  // 详情页预览图
   width?: number;
   height?: number;
   size?: number;
@@ -162,7 +164,19 @@ class UploadService {
     for (const file of files) {
       const result = await this.uploadImage(file);
       if (result) {
-        urls.push(result.url);
+        // 将预览图信息合并到 URL 中：url|preview_url|preview_url_large
+        const parts = [result.url];
+        if (result.preview_url) {
+          parts.push(result.preview_url);
+        } else {
+          parts.push(''); // 空占位
+        }
+        if (result.preview_url_large) {
+          parts.push(result.preview_url_large);
+        } else {
+          parts.push(''); // 空占位
+        }
+        urls.push(parts.join('|'));
       }
     }
     

src/types/dto.ts

@@ -52,6 +52,8 @@ export interface PostImageDTO {
   id: string;
   url: string;
   thumbnail_url: string;
+  preview_url: string;        // 列表/网格预览图
+  preview_url_large: string;  // 详情页预览图
   width: number;
   height: number;
 }

src/utils/imageHelper.ts

@@ -0,0 +1,101 @@
+/**
+ * 图片工具函数
+ * 提供图片 URL 选择、格式检测等实用功能
+ */
+
+import { PostImageDTO } from '../types';
+
+/**
+ * 图片显示模式
+ */
+export type ImageDisplayMode = 'list' | 'grid' | 'detail';
+
+/**
+ * 根据显示模式获取预览图 URL
+ * @param image 图片对象
+ * @param mode 显示模式
+ * @returns 图片 URL
+ */
+export function getPreviewImageUrl(image: PostImageDTO, mode: ImageDisplayMode): string {
+  // 如果没有预览图，返回原图
+  if (!image) {
+    return '';
+  }
+
+  switch (mode) {
+    case 'list':
+    case 'grid':
+      // 列表和网格模式使用普通预览图
+      return image.preview_url || image.url || '';
+    case 'detail':
+      // 详情页使用大预览图
+      return image.preview_url_large || image.preview_url || image.url || '';
+    default:
+      return image.url || '';
+  }
+}
+
+/**
+ * 检测 WebP 支持并构建 Accept header
+ * @returns Accept header 字符串
+ */
+export function getImageAcceptHeader(): string {
+  // 检测浏览器是否支持 WebP
+  // 如果支持，优先请求 WebP
+  return 'image/webp,image/apng,image/*,*/*;q=0.8';
+}
+
+/**
+ * 判断是否应该使用预览图
+ * @param mode 显示模式
+ * @param hasPreview 是否有预览图
+ * @returns 是否使用预览图
+ */
+export function shouldUsePreview(mode: ImageDisplayMode, hasPreview: boolean): boolean {
+  // 列表和网格模式优先使用预览图
+  if (mode === 'list' || mode === 'grid') {
+    return hasPreview;
+  }
+  // 详情页也使用预览图，但点击后加载原图
+  if (mode === 'detail') {
+    return hasPreview;
+  }
+  return false;
+}
+
+/**
+ * 从图片 URL 提取文件扩展名
+ * @param url 图片 URL
+ * @returns 文件扩展名（如 '.jpg'）
+ */
+export function getImageExtension(url: string): string {
+  if (!url) return '';
+  try {
+    const urlObj = new URL(url);
+    const pathname = urlObj.pathname;
+    const ext = pathname.match(/\.[0-9a-z]+$/i);
+    return ext ? ext[0].toLowerCase() : '';
+  } catch {
+    // 如果 URL 解析失败，直接从字符串匹配
+    const match = url.match(/\.[0-9a-z]+$/i);
+    return match ? match[0].toLowerCase() : '';
+  }
+}
+
+/**
+ * 判断是否是 GIF 图片
+ * @param url 图片 URL
+ * @returns 是否是 GIF
+ */
+export function isGifImage(url: string): boolean {
+  return getImageExtension(url) === '.gif';
+}
+
+/**
+ * 判断是否是 WebP 图片
+ * @param url 图片 URL
+ * @returns 是否是 WebP
+ */
+export function isWebPImage(url: string): boolean {
+  return getImageExtension(url) === '.webp';
+}