Java 无法将片段显示为活动

您好，我正在尝试将我的片段加载到活动中，但无法将其加载。有人能告诉我我做错了什么吗？我的工具栏位于activity中，但我的片段包含一个来自Facebook的textview和profilepictureview。由于无法显示textview和profilepicture视图，我缺少了什么

下面是我的第一个_fragment.xml：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:id="@+id/fragmentPic">

    <TextView
        android:id="@+id/textName"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/users_FirstName"
        android:textSize="@dimen/font_size"
        android:hint="JJJJ"
        android:layout_gravity="center_horizontal"/>

    <com.facebook.login.widget.ProfilePictureView
        android:id="@+id/profilePic"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"
        >
    </com.facebook.login.widget.ProfilePictureView>

</LinearLayout>

secondActivity.java：

     public class secondActivity extends AppCompatActivity {

      private Intent intent;
      private Toolbar toolbar;
     @Override
     protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_second);

        intent = getIntent();
        String firstName = intent.getStringExtra("firstName");
        String userId = intent.getStringExtra("Id");

        toolbar = (Toolbar)findViewById(R.id.toolBar);
        setSupportActionBar(toolbar);
        toolbar.setLogo(R.drawable.ic_menu_image);
        getSupportActionBar().setDisplayShowHomeEnabled(true);
        getSupportActionBar().setDisplayShowTitleEnabled(false);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_second, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }
  }

---

我解决了问题，调用了错误的布局文件

View rootView = inflater.inflate(R.layout.event_fragment, container, false);

应该是：

View rootView = inflater.inflate(R.layout.first_fragment, container, false);

     public class secondActivity extends AppCompatActivity {

      private Intent intent;
      private Toolbar toolbar;
     @Override
     protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_second);

        intent = getIntent();
        String firstName = intent.getStringExtra("firstName");
        String userId = intent.getStringExtra("Id");

        toolbar = (Toolbar)findViewById(R.id.toolBar);
        setSupportActionBar(toolbar);
        toolbar.setLogo(R.drawable.ic_menu_image);
        getSupportActionBar().setDisplayShowHomeEnabled(true);
        getSupportActionBar().setDisplayShowTitleEnabled(false);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_second, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }
  }

View rootView = inflater.inflate(R.layout.event_fragment, container, false);

View rootView = inflater.inflate(R.layout.first_fragment, container, false);