优化打印机连接

src/pages/CounterMixins.js

@@ -120,8 +120,7 @@ const CounterMixins = ComposeComponent => {
         await handleScan();
         this.barcode = '';
       });
-      const isConnected = await Printer.isConnected();
-      if (!isConnected) await Printer.usbConnect(); // 尝试连接打印机模块
+      this.printerConnect();
       this.listen();
     };
 
@@ -132,6 +131,11 @@ const CounterMixins = ComposeComponent => {
       KeyEvent.removeKeyUpListener();
     };
 
+    printerConnect = async () => {
+      const isConnected = await Printer.isConnected();
+      if (!isConnected) await Printer.usbConnect(); // 尝试连接打印机模块
+    };
+
     setDelay = debounce(delay, true, () => {
       this.isDelay = true;
       setTimeout(() => {