diff --git a/src/src/Rendering/Measure/RulerAnnotationActor.cpp b/src/src/Rendering/Measure/RulerAnnotationActor.cpp
index 61b04a0..f0e46e5 100644
--- a/src/src/Rendering/Measure/RulerAnnotationActor.cpp
+++ b/src/src/Rendering/Measure/RulerAnnotationActor.cpp
@@ -20,7 +20,18 @@
 
 vtkStandardNewMacro(RulerAnnotationActor)
 
-RulerAnnotationActor::RulerAnnotationActor() {
+void RulerAnnotationActor::SetDistanceName(const QString &aName)
+{
+    mDistance = aName;
+}
+
+QString RulerAnnotationActor::GetDistanceName()
+{
+    return mDistance;
+}
+
+RulerAnnotationActor::RulerAnnotationActor()
+{
     text = vtkActor2D::New();
     vtkNew<vtkTextMapper> textMapper;
     textMapper->SetInput("0");
@@ -64,7 +75,7 @@ void RulerAnnotationActor::BuildShape() {
     // p1[2] = 0.0;
     // p2[2] = 0.0;
     realDistance = std::sqrt(vtkMath::Distance2BetweenPoints(p1, p2));
-
+    this->InvokeEvent(MeasureChangedEvent,&realDistance);
     double dis;
     if (isCalibration) {
         dis = calibDistance;
diff --git a/src/src/Rendering/Measure/RulerAnnotationActor.h b/src/src/Rendering/Measure/RulerAnnotationActor.h
index cb7c959..2e30f14 100644
--- a/src/src/Rendering/Measure/RulerAnnotationActor.h
+++ b/src/src/Rendering/Measure/RulerAnnotationActor.h
@@ -32,6 +32,14 @@ public:
         }
     }
 
+    void SetDistanceName(const QString& aName);
+    QString GetDistanceName();
+
+    double GetRealDistance(){
+        return realDistance;
+    }
+
+
 protected:
     RulerAnnotationActor();