diff --git a/students/net1814080903109/TurnoffScreenActivity.java b/students/net1814080903109/TurnoffScreenActivity.java
index 5e6a7a652..f1743e740 100644
--- a/students/net1814080903109/TurnoffScreenActivity.java
+++ b/students/net1814080903109/TurnoffScreenActivity.java
@@ -2,13 +2,45 @@
 
 import androidx.appcompat.app.AppCompatActivity;
 
+import android.app.admin.DevicePolicyManager;
+import android.content.ComponentName;
+import android.content.Context;
+import android.content.Intent;
 import android.os.Bundle;
+import android.os.SystemClock;
+import android.view.View;
 
 public class TurnoffScreenActivity extends AppCompatActivity {
+    ComponentName mAdminName;
+    DevicePolicyManager mDPM;
+
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.turnoffscreen);
+
+        mAdminName = new ComponentName(this, AdminManageReceiver.class);
+        mDPM = (DevicePolicyManager) getSystemService(Context.DEVICE_POLICY_SERVICE);
+
+        //如果设备管理器尚未激活，这里会启动一个激活设备管理器的Intent,具体的表现就是第一次打开程序时，手机会弹出激活设备管理器的提示，激活即可。
+        if (!mDPM.isAdminActive(mAdminName)) {
+            showAdminManagement(mAdminName);
+        }
+    }
+
+    //执行锁屏
+    public void lockScreen(View view){
+        if (mDPM.isAdminActive(mAdminName)) {
+            mDPM.lockNow();
+        }
+    }
+
+    //激活设备管理器
+    private void showAdminManagement(ComponentName mAdminName) {
+        Intent intent = new Intent(DevicePolicyManager.ACTION_ADD_DEVICE_ADMIN);
+        intent.putExtra(DevicePolicyManager.EXTRA_DEVICE_ADMIN, mAdminName);
+        intent.putExtra(DevicePolicyManager.EXTRA_ADD_EXPLANATION, "activity device");
+        startActivityForResult(intent,1);
     }
 }
\ No newline at end of file
diff --git a/students/net1814080903109/turnoffscreen.xml b/students/net1814080903109/turnoffscreen.xml
index 72a1b24d7..3c6e3d1d7 100644
--- a/students/net1814080903109/turnoffscreen.xml
+++ b/students/net1814080903109/turnoffscreen.xml
@@ -37,19 +37,20 @@
         tools:ignore="DuplicateIds,MissingConstraints" />
 
     <Button
-        android:id="@+id/view2"
+        android:id="@+id/button"
         android:layout_width="171dp"
         android:layout_height="171dp"
         android:background="@drawable/turnoff"
         android:text="熄屏"
-
+        android:onClick="lockScreen"
         android:textAlignment="center"
         android:textColor="#fffaaa"
         android:textSize="20dp"
         app:layout_constraintBottom_toBottomOf="parent"
         app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintHorizontal_bias="0.541"
         app:layout_constraintStart_toStartOf="parent"
         app:layout_constraintTop_toTopOf="parent"
-        app:layout_constraintVertical_bias="0.246"
-        tools:ignore="DuplicateIds,MissingConstraints" />
+        app:layout_constraintVertical_bias="0.458"
+        tools:ignore="DuplicateIds,MissingConstraints,OnClick" />
 </androidx.constraintlayout.widget.ConstraintLayout>
\ No newline at end of file
diff --git a/students/net1814080903109/xml/device_admin.xml b/students/net1814080903109/xml/device_admin.xml
new file mode 100644
index 000000000..7c4ce1430
--- /dev/null
+++ b/students/net1814080903109/xml/device_admin.xml
@@ -0,0 +1,5 @@
+<device-admin xmlns:android="http://schemas.android.com/apk/res/android">
+    <uses-policies>
+        <force-lock />
+    </uses-policies>
+</device-admin>
\ No newline at end of file