diff --git a/app/build.gradle b/app/build.gradle
index 75f3c15..1b2b0c6 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -24,14 +24,22 @@ android {
 }
 
 dependencies {
-    implementation 'androidx.appcompat:appcompat:1.1.0'
+    implementation fileTree(dir: 'libs', include: ['*.jar'])
+    implementation 'androidx.appcompat:appcompat:1.0.2'
     implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
     testImplementation 'junit:junit:4.12'
     androidTestImplementation 'androidx.test.ext:junit:1.1.0'
     androidTestImplementation 'androidx.test.espresso:espresso-core:3.1.1'
     api 'com.hankcs:hanlp:portable-1.7.2'
     implementation 'com.google.android.material:material:1.0.0'
-    androidTestImplementation 'androidx.test.ext:junit:1.1.1'
-    androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'
-    implementation fileTree(dir: 'libs', include: ['*.aar', '*.jar'], exclude: [])
+//    implementation 'androidx.appcompat:appcompat:1.1.0'
+//    implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
+//    testImplementation 'junit:junit:4.12'
+//    androidTestImplementation 'androidx.test.ext:junit:1.1.0'
+//    androidTestImplementation 'androidx.test.espresso:espresso-core:3.1.1'
+//    api 'com.hankcs:hanlp:portable-1.7.2'
+//    implementation 'com.google.android.material:material:1.0.0'
+//    androidTestImplementation 'androidx.test.ext:junit:1.1.1'
+//    androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'
+//    implementation fileTree(dir: 'libs', include: ['*.aar', '*.jar'], exclude: [])
 }
diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index 077ed49..3dc12a9 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -15,7 +15,9 @@
         android:roundIcon="@mipmap/ic_launcher_round"
         android:supportsRtl="true"
         android:theme="@style/AppTheme">
-
+        <activity android:name=".PersonalityCenterActivity" />
+        <activity android:name=".LoginActivity" />
+        <activity android:name=".RegisterActivity" />
 
         <activity android:name=".MainActivity">
             <intent-filter>
diff --git a/app/src/main/java/com/example/cmknowledgegraph/MainActivity.java b/app/src/main/java/com/example/cmknowledgegraph/MainActivity.java
index 046b46e..6eedf28 100644
--- a/app/src/main/java/com/example/cmknowledgegraph/MainActivity.java
+++ b/app/src/main/java/com/example/cmknowledgegraph/MainActivity.java
@@ -1,22 +1,78 @@
 package com.example.cmknowledgegraph;
 
+import android.os.Bundle;
+
+import com.example.cmknowledgegraph.MainContent;
+import com.example.cmknowledgegraph.R;
+import com.example.cmknowledgegraph.SearchContent;
+import com.google.android.material.bottomnavigation.BottomNavigationView;
+import com.hankcs.hanlp.HanLP;
+
 import androidx.appcompat.app.AppCompatActivity;
+import androidx.annotation.NonNull;
+import androidx.fragment.app.FragmentManager;
+import androidx.fragment.app.FragmentTransaction;
 
-import android.os.Bundle;
-import android.util.Log;
-import android.view.View;
-import android.widget.Button;
+import android.view.MenuItem;
+import android.widget.TextView;
 
-import com.example.PersonalCenter.Login;
-import com.example.PersonalCenter.Register;
+import java.util.List;
 
 public class MainActivity extends AppCompatActivity {
+    private TextView mTextMessage;
+    private FragmentTransaction transaction;
+    private FragmentManager fragmentManager;
+
+    private BottomNavigationView.OnNavigationItemSelectedListener mOnNavigationItemSelectedListener
+            = new BottomNavigationView.OnNavigationItemSelectedListener() {
 
-    @Override
-    protected void onCreate(Bundle savedInstanceState) {
+        @Override
+
+
+        public boolean onNavigationItemSelected(MenuItem item) {
+            fragmentManager = getSupportFragmentManager();  //使用fragmentmanager和transaction来实现切换效果
+            transaction = fragmentManager.beginTransaction();
+            switch (item.getItemId()) {
+                case R.id.home:
+                    transaction.replace(R.id.content,new MainContent());  //对应的java class
+                    transaction.commit();  //一定不要忘记commit，否则不会显示
+                    return true;
+                case R.id.search:
+                    transaction.replace(R.id.content,new SearchContent());  //对应的java class
+                    transaction.commit();  //一定不要忘记commit，否则不会显示
+                    return true;
+                case R.id.chat:
+                    return true;
+                case R.id.person:
+                    transaction.replace(R.id.content,new PersonContent());  //对应的java class
+                    transaction.commit();  //一定不要忘记commit，否则不会显示
+                    return true;
+            }
+            return false;
+        }
+
+    };
+// 设置默认进来是tab 显示的页面
+private void setDefaultFragment(){
+        fragmentManager = getSupportFragmentManager();
+        transaction = fragmentManager.beginTransaction();
+        transaction.replace(R.id.content,new MainContent());
+        transaction.commit();
+        }
+
+@Override
+protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);
-        System.out.println("haha");
+        setDefaultFragment();  //上面写的那个函数
+        BottomNavigationView navView = findViewById(R.id.nav_view);
+        mTextMessage = findViewById(R.id.message);
+        navView.setOnNavigationItemSelectedListener(mOnNavigationItemSelectedListener);
+
+        //HanLP测试
+        String content = "发烧感冒";
+        List<String> keywordList = HanLP.extractKeyword(content, 5);
+        System.out.println(keywordList);
+        }
 
-    }
-}
+        }
\ No newline at end of file
diff --git a/app/src/main/res/layout/activity_main.xml b/app/src/main/res/layout/activity_main.xml
index a70c2b1..79a01bf 100644
--- a/app/src/main/res/layout/activity_main.xml
+++ b/app/src/main/res/layout/activity_main.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto"
     xmlns:tools="http://schemas.android.com/tools"
     android:id="@+id/container"
@@ -26,12 +26,4 @@
         app:layout_constraintRight_toRightOf="parent"
         app:menu="@menu/bottom_nav_menu" />
 
-    <Button
-        android:id="@+id/button2"
-        android:layout_width="wrap_content"
-        android:layout_height="wrap_content"
-        android:text="Button"
-        tools:layout_editor_absoluteX="189dp"
-        tools:layout_editor_absoluteY="272dp" />
-
-</LinearLayout>
\ No newline at end of file
+</androidx.constraintlayout.widget.ConstraintLayout>
\ No newline at end of file