当只上传一张图片时，默认最小高度为一张图片的最小高度

src/views/book/courseware/create/components/base/picture/Picture.vue

@@ -43,6 +43,9 @@ export default {
       this.data.file_list = file_list;
       this.data.file_id_list = file_id_list;
       this.data.file_info_list = file_info_list;
+      if (file_list.length === 1) {
+        this.data.min_height = '144';
+      }
       this.handlerMindMap();
     },
     // 思维导图

src/views/book/courseware/preview/components/picture/PicturePreview.vue

@@ -51,7 +51,7 @@
               :src="file.file_url"
               fit="contain"
               :preview-src-list="data.file_list.map((x) => x.file_url)"
-              :style="{ height: elementHeight <= 0 ? data.min_height - 144 + 'px' : elementHeight + 'px' }"
+              :style="{ height: elementHeight <= 0 ? data.min_height + 'px' : elementHeight + 'px' }"
             />
           </div>
         </template>