这一版本优化了很多

unpackage/dist/dev/mp-weixin/utils/watermark.js

@@ -0,0 +1,68 @@
+"use strict";
+const common_vendor = require("../common/vendor.js");
+function addTimestampWatermark({ tempFilePath, canvasId = "watermarkCanvas", canvasWidthRef, canvasHeightRef, instance }) {
+  return new Promise((resolve, reject) => {
+    common_vendor.index.getImageInfo({
+      src: tempFilePath,
+      success: (imageInfo) => {
+        const imgWidth = imageInfo.width;
+        const imgHeight = imageInfo.height;
+        if (canvasWidthRef && canvasWidthRef.value !== void 0) {
+          canvasWidthRef.value = imgWidth;
+        }
+        if (canvasHeightRef && canvasHeightRef.value !== void 0) {
+          canvasHeightRef.value = imgHeight;
+        }
+        common_vendor.nextTick$1(() => {
+          const ctx = common_vendor.index.createCanvasContext(canvasId, instance);
+          if (!ctx) {
+            reject("创建水印画布上下文失败");
+            return;
+          }
+          ctx.drawImage(tempFilePath, 0, 0, imgWidth, imgHeight);
+          const now = /* @__PURE__ */ new Date();
+          const year = now.getFullYear();
+          const month = String(now.getMonth() + 1).padStart(2, "0");
+          const day = String(now.getDate()).padStart(2, "0");
+          const hours = String(now.getHours()).padStart(2, "0");
+          const minutes = String(now.getMinutes()).padStart(2, "0");
+          const seconds = String(now.getSeconds()).padStart(2, "0");
+          const timeStr = `${year}-${month}-${day} ${hours}:${minutes}:${seconds}`;
+          const fontSize = Math.max(14, Math.floor(imgWidth * (14 / 375)));
+          ctx.setFontSize(fontSize);
+          ctx.setFillStyle("#C9CBD4");
+          ctx.setShadow(2, 2, 4, "rgba(0, 0, 0, 0.6)");
+          const padding = fontSize;
+          const textWidth = timeStr.length * (fontSize * 0.55);
+          const x = imgWidth - textWidth - padding;
+          const y = imgHeight - padding;
+          ctx.fillText(timeStr, x, y);
+          ctx.draw(false, () => {
+            setTimeout(() => {
+              common_vendor.index.canvasToTempFilePath({
+                canvasId,
+                destWidth: imgWidth,
+                destHeight: imgHeight,
+                fileType: "jpg",
+                quality: 0.9,
+                success: (exportRes) => {
+                  resolve(exportRes.tempFilePath);
+                },
+                fail: (err) => {
+                  common_vendor.index.__f__("error", "at utils/watermark.js:80", "导出带水印图片失败:", err);
+                  reject(err);
+                }
+              }, instance);
+            }, 150);
+          });
+        });
+      },
+      fail: (err) => {
+        common_vendor.index.__f__("error", "at utils/watermark.js:89", "获取图片信息失败:", err);
+        reject(err);
+      }
+    });
+  });
+}
+exports.addTimestampWatermark = addTimestampWatermark;
+//# sourceMappingURL=../../.sourcemap/mp-weixin/utils/watermark.js.map