diff --git a/testHasttable/element/line.cpp b/testHasttable/element/line.cpp
index 1a15749..10ea17c 100644
--- a/testHasttable/element/line.cpp
+++ b/testHasttable/element/line.cpp
@@ -4,6 +4,7 @@ Line::Line(const QPair<QString,QString>& fromTo, ACLineSegment* ac):Branch(fromT
 {
     this->ratio=1;
     this->ac=ac;
+    this->extract();
 }
 
 
diff --git a/testHasttable/element/switch.cpp b/testHasttable/element/switch.cpp
new file mode 100644
index 0000000..7be1876
--- /dev/null
+++ b/testHasttable/element/switch.cpp
@@ -0,0 +1,24 @@
+#include "switch.h"
+
+Switch::Switch(const QPair<QString,QString>& fromTo):Branch(fromTo.first,fromTo.second)
+{
+    this->extract();
+}
+
+
+void Switch::extract()
+{
+//    PowerTransformer *tf=this->tf;
+    double length=10;
+    //单位阻抗
+    double r0=0.01;
+    double x0=0.01;
+    double g0=0;
+    double b0=0;
+    this->r=r0*length;
+    this->x=x0*length;
+    this->g1=g0*length;
+    this->g2=g0*length;
+    this->b1=b0*length;
+    this->b2=b0*length;
+}
diff --git a/testHasttable/element/switch.h b/testHasttable/element/switch.h
new file mode 100644
index 0000000..60bd265
--- /dev/null
+++ b/testHasttable/element/switch.h
@@ -0,0 +1,14 @@
+#ifndef SWITCH_H
+#define SWITCH_H
+#include <QPair>
+#include "branch.h"
+class Switch:public Branch
+{
+public:
+    Switch(const QPair<QString, QString> &fromTo);
+protected:
+    virtual void extract();
+
+};
+
+#endif // SWITCH_H
diff --git a/testHasttable/element/transformer.cpp b/testHasttable/element/transformer.cpp
index 5695e5d..84ed4c6 100644
--- a/testHasttable/element/transformer.cpp
+++ b/testHasttable/element/transformer.cpp
@@ -5,6 +5,7 @@ Transformer::Transformer(const QPair<QString,QString>& fromTo, PowerTransformer*
 {
     this->ratio=1;
     this->tf=tf;
+    this->extract();
 }
 
 
diff --git a/testHasttable/testHasttable.pro b/testHasttable/testHasttable.pro
index e8f4798..3a32da4 100644
--- a/testHasttable/testHasttable.pro
+++ b/testHasttable/testHasttable.pro
@@ -35,7 +35,8 @@ SOURCES += main.cpp \
     cimexporter.cpp \
     element/branch.cpp \
     element/line.cpp \
-    element/transformer.cpp
+    element/transformer.cpp \
+    element/switch.cpp
 
 HEADERS += \
     elementhashtable.h \
@@ -56,7 +57,8 @@ HEADERS += \
     cimexporter.h \
     element/branch.h \
     element/line.h \
-    element/transformer.h
+    element/transformer.h \
+    element/switch.h
 
 #release{
 DEFINES += QT_NO_DEBUG_OUTPUT