修复内存溢出问题

src/components/ImageCanvas.tsx

@@ -77,6 +77,13 @@ export const ImageCanvas: React.FC = () => {
       
       img.src = canvasImage;
     } else {
+      // 当没有图像时，清理之前的图像对象
+      if (image) {
+        // 清理图像对象以释放内存
+        image.onload = null;
+        image.onerror = null;
+        image.src = '';
+      }
       setImage(null);
     }
     
@@ -86,9 +93,18 @@ export const ImageCanvas: React.FC = () => {
       if (img) {
         img.onload = null;
         img.onerror = null;
+        // 清理图像源以释放内存
+        img.src = '';
+      }
+      
+      // 清理之前的图像对象
+      if (image) {
+        image.onload = null;
+        image.onerror = null;
+        image.src = '';
       }
     };
-  }, [canvasImage, stageSize, setCanvasZoom, setCanvasPan]);
+  }, [canvasImage, stageSize, setCanvasZoom, setCanvasPan, image]);
 
   // 处理舞台大小调整
   useEffect(() => {