fix code

miniprogram/pages/upload/upload.ts

@@ -914,6 +914,9 @@ Page({
       }
       const stripCentered = strip.length <= 5;
       this.setData({ dateStripItems: strip, imagesByDate, selectedDateKey: selectedKey, selectedDateImages: selectedImages, gridCols, selectedMonthTitle: monthTitle, useWaterfall, waterfallLeft, waterfallRight, stripCentered });
+      if (useWaterfall) {
+        this.balanceWaterfall(selectedImages);
+      }
     } catch (err) {
       console.error('重建日期条失败:', err);
     }
@@ -931,6 +934,68 @@ Page({
       images.forEach((img, idx) => { (idx % 2 === 0 ? waterfallLeft : waterfallRight).push(img); });
     }
     this.setData({ selectedDateKey: dateKey, selectedDateImages: images, gridCols, selectedMonthTitle: `${y}-${String(m).padStart(2,'0')}`, useWaterfall, waterfallLeft, waterfallRight });
+    if (useWaterfall) {
+      this.balanceWaterfall(images);
+    }
+  },
+
+  async ensureThumbSize(img: any): Promise<{ w: number; h: number } | null> {
+    if (img && typeof img._thumbW === 'number' && typeof img._thumbH === 'number') {
+      return { w: img._thumbW, h: img._thumbH };
+    }
+    const src = img && img.thumbnail_url;
+    if (!src) return null;
+    return new Promise((resolve) => {
+      wx.getImageInfo({
+        src,
+        success: (res) => {
+          img._thumbW = res.width;
+          img._thumbH = res.height;
+          resolve({ w: res.width, h: res.height });
+        },
+        fail: () => {
+          resolve(null);
+        }
+      });
+    });
+  },
+
+  async computeWaterfallColumns(images: any[]): Promise<{ left: any[]; right: any[] }> {
+    const si = wx.getSystemInfoSync();
+    const ww = si.windowWidth;
+    const rpx = ww / 750;
+    const padPx = Math.floor(24 * rpx);
+    const gapPx = Math.floor(12 * rpx);
+    const colW = Math.max(1, Math.floor((ww - padPx - gapPx) / 2));
+    const mbPx = Math.floor(12 * rpx);
+    let leftH = 0;
+    let rightH = 0;
+    const left: any[] = [];
+    const right: any[] = [];
+    const infos = await Promise.all(images.map((img) => this.ensureThumbSize(img)));
+    for (let i = 0; i < images.length; i++) {
+      const img = images[i];
+      const info = infos[i];
+      let h = 200;
+      if (info && info.w > 0) {
+        h = Math.floor(info.h * (colW / info.w));
+      }
+      if (leftH <= rightH) {
+        left.push(img);
+        leftH += h + mbPx;
+      } else {
+        right.push(img);
+        rightH += h + mbPx;
+      }
+    }
+    return { left, right };
+  },
+
+  async balanceWaterfall(images: any[]) {
+    try {
+      const { left, right } = await this.computeWaterfallColumns(images);
+      this.setData({ waterfallLeft: left, waterfallRight: right });
+    } catch (e) {}
   },
 
 })