diff --git a/DSView/pv/config/appconfig.h b/DSView/pv/config/appconfig.h
index 95e9f834..e68dd203 100644
--- a/DSView/pv/config/appconfig.h
+++ b/DSView/pv/config/appconfig.h
@@ -30,6 +30,7 @@
 #define LAN_EN  31
 
 //#define DARK_STYLE  "dark"
+#define APP_NAME  "DSView"
   
 //--------------------api---
 
diff --git a/DSView/pv/mainwindow.cpp b/DSView/pv/mainwindow.cpp
index 87a0da61..c8bc5c70 100644
--- a/DSView/pv/mainwindow.cpp
+++ b/DSView/pv/mainwindow.cpp
@@ -881,7 +881,7 @@ void MainWindow::on_search(bool visible)
 void MainWindow::on_screenShot()
 {
     AppConfig &app = AppConfig::Instance();     
-    QString default_name = app._userHistory.screenShotPath + "/DSView" + QDateTime::currentDateTime().toString("-yyMMdd-hhmmss");
+    QString default_name = app._userHistory.screenShotPath + "/" + APP_NAME + QDateTime::currentDateTime().toString("-yyMMdd-hhmmss");
 
 #if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
     QScreen *scr = QGuiApplication::primaryScreen();
diff --git a/DSView/pv/sigsession.cpp b/DSView/pv/sigsession.cpp
index adf1a5f4..094c446b 100755
--- a/DSView/pv/sigsession.cpp
+++ b/DSView/pv/sigsession.cpp
@@ -1212,10 +1212,10 @@ void SigSession::hotplug_callback(void *ctx, void *dev, int event, void *user_da
     (void)dev;
     (void)user_data;
 
-    if (1 == event) {
+    if (USB_EV_HOTPLUG_ATTACH == event) {
         _session->_hot_attach = true;
         qDebug("receive event:DreamSourceLab Hardware attached!");
-    }else if (2 == event) {
+    }else if (USB_EV_HOTPLUG_DETTACH == event) {
         _session->_hot_detach = true;
         qDebug("receive event:DreamSourceLab Hardware detached!");
     }else{
diff --git a/libsigrok4DSL/backend.c b/libsigrok4DSL/backend.c
index 156922f5..164c5b37 100755
--- a/libsigrok4DSL/backend.c
+++ b/libsigrok4DSL/backend.c
@@ -416,9 +416,15 @@ LIBUSB_CALL int sr_hotplug_callback(struct libusb_context *ctx, struct libusb_de
 		 return 0;
 	  }
 
+	  int ev = USB_EV_HOTPLUG_UNKNOW;
+	  if (event == (int)LIBUSB_HOTPLUG_EVENT_DEVICE_ARRIVED)
+	  	 ev = USB_EV_HOTPLUG_ATTACH;
+	  else if (event == (int)LIBUSB_HOTPLUG_EVENT_DEVICE_LEFT)
+	  	 ev = USB_EV_HOTPLUG_DETTACH;
+
       struct sr_context *user_ctx = (struct sr_context*)user_data;
 	  if (user_ctx->hotplug_callback != NULL){
-		  user_ctx->hotplug_callback(ctx, dev, (int)event, user_ctx->hotplug_user_data);
+		  user_ctx->hotplug_callback(ctx, dev, ev, user_ctx->hotplug_user_data);
 	  }
 
 	  return 0;
diff --git a/libsigrok4DSL/libsigrok.h b/libsigrok4DSL/libsigrok.h
index 47a3f97f..18807c7d 100755
--- a/libsigrok4DSL/libsigrok.h
+++ b/libsigrok4DSL/libsigrok.h
@@ -174,6 +174,11 @@ enum {
 #define SR_PRIV
 #endif
 
+
+#define USB_EV_HOTPLUG_UNKNOW		0
+#define USB_EV_HOTPLUG_ATTACH		1
+#define USB_EV_HOTPLUG_DETTACH		2
+
   
 /** Data types used by sr_config_info(). */
 enum {