1

src/components/UploadCover/upload-from-wx.tsx

@@ -15,7 +15,7 @@ export interface UploadFromWxProps {
 
 async function convert_to_jpg_and_compress(
   src: string,
-  { width, height }
+  { width, height, quality }: { width: number; height: number; quality: number }
 ): Promise<string> {
   const canvas = Taro.createOffscreenCanvas({ type: "2d", width, height });
   const ctx = canvas.getContext("2d") as CanvasRenderingContext2D;
@@ -33,22 +33,54 @@ async function convert_to_jpg_and_compress(
   return new Promise((resolve, reject) => {
     Taro.canvasToTempFilePath({
       canvas: canvas as unknown as Taro.Canvas,
-      fileType: "png",
-      quality: 0.7,
+      fileType: "jpg",
+      quality,
       success: (res) => resolve(res.tempFilePath),
       fail: reject,
     });
   });
 }
 
+function getFileSize(path: string): Promise<number> {
+  const fs = (Taro as any).getFileSystemManager();
+  return new Promise((resolve, reject) => {
+    fs.stat({
+      path,
+      success: (res) => resolve(res.stats.size),
+      fail: reject,
+    });
+  });
+}
+
 async function compressImage(files) {
   const res: string[] = [];
+  const qualityList = [0.9, 0.85, 0.8, 0.75, 0.7, 0.65, 0.6];
+
   for (const file of files) {
-    const compressed_image = await convert_to_jpg_and_compress(file.path, {
-      width: file.width,
-      height: file.height,
-    });
-    res.push(compressed_image);
+    // 小图且体积已在目标范围内时，直接上传原图，避免二次压缩变糊
+    if (
+      file.size <= TARGET_IMAGE_SIZE &&
+      file.width <= IMAGE_MAX_SIZE.width &&
+      file.height <= IMAGE_MAX_SIZE.height
+    ) {
+      res.push(file.path);
+      continue;
+    }
+
+    let bestImage = file.path;
+    for (const quality of qualityList) {
+      const compressedImage = await convert_to_jpg_and_compress(file.path, {
+        width: file.width,
+        height: file.height,
+        quality,
+      });
+      const compressedSize = await getFileSize(compressedImage);
+      bestImage = compressedImage;
+      if (compressedSize <= TARGET_IMAGE_SIZE) {
+        break;
+      }
+    }
+    res.push(bestImage);
   }
   return res;
 }
@@ -58,6 +90,8 @@ const IMAGE_MAX_SIZE = {
   width: 1080,
   height: 720,
 };
+// 压缩目标体积（约 300KB）
+const TARGET_IMAGE_SIZE = 800 * 1024;
 
 // 标准长宽比，判断标准
 const STANDARD_ASPECT_RATIO = IMAGE_MAX_SIZE.width / IMAGE_MAX_SIZE.height;