Merge remote-tracking branch 'origin/master'

# Conflicts:
#	app/src/main/res/layout/activity_main.xml

app/src/main/java/com/example/cmknowledgegraph/MainActivity.java

@@ -44,6 +44,8 @@ public class MainActivity extends AppCompatActivity {
                 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;

app/src/main/java/com/example/cmknowledgegraph/PersonContent.java

@@ -0,0 +1,17 @@
+package com.example.cmknowledgegraph;
+
+import android.os.Bundle;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+
+import androidx.fragment.app.Fragment;
+
+public class PersonContent extends Fragment {
+
+    public View onCreateView(LayoutInflater inflater, ViewGroup container,
+                             Bundle savedInstanceState) {
+        // Inflate the layout for this fragment
+        return inflater.inflate( R.layout.activity_personality_center, container, false );  //要加载的layout文件
+    }
+}