MainActivity隐藏的导航抽屉

Question

我是Android的新手，我第一次使用导航抽屉。我想我有些搞砸了。当我打开我的应用程序时，我的主要活动XML布局上的字段显示正常。但是，当我选择导航抽屉时，它出现在主窗体后面，看起来是半透明的。我无法选择导航抽屉上的任何选项。

我是否需要将mainActivity.java和mainactivity.xml上的UI和相关代码移动到片段中并默认加载？我的mainactivity.xml有问题吗？

谢谢，

杰里

<!-- A DrawerLayout is intended to be used as the top-level content view using 
  match_parent for both width and height to consume the full space available. -->
<android.support.v4.widget.DrawerLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/drawer_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.developer.symptom.androidclient.MainActivity">

<!-- As the main content view, the view below consumes the entire
     space available using match_parent in both dimensions. -->
<FrameLayout
    android:id="@+id/container"
    android:layout_width="match_parent"
    android:layout_height="match_parent" />

<!-- android:layout_gravity="start" tells DrawerLayout to treat
     this as a sliding drawer on the left side for left-to-right
     languages and on the right side for right-to-left languages.
     If you're not building against API 17 or higher, use
     android:layout_gravity="left" instead. -->
<!-- The drawer is given a fixed width in dp and extends the full height of
     the container. -->
<fragment android:id="@+id/navigation_drawer"
    android:layout_width="@dimen/navigation_drawer_width"
    android:layout_height="match_parent"
    android:layout_gravity="start"
    android:name="com.developer.symptom.androidclient.NavigationDrawerFragment" />

<!-- views used by main activity     -->
<LinearLayout android:layout_width="fill_parent" android:layout_height="match_parent" 
  android:orientation="vertical" android:visibility="gone">

    <!-- Welcome message   -->
    <TextView android:layout_width="fill_parent" android:layout_height="wrap_content"
        android:layout_marginTop="12dp"    android:layout_marginLeft="40dp"
        android:textSize="20dp"  android:text="Welcome" 
      android:id="@+id/main_welcome"/>

    <!-- Data of birth and medical record number -->
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal">
        <TextView
            android:layout_width="wrap_content" android:layout_marginLeft="15dp"
            android:layout_height="wrap_content"
            android:text="@string/date_of_birth_prompt"/>
        <TextView
            android:layout_width="wrap_content" android:layout_marginLeft="5dp"
            android:layout_height="wrap_content" android:id="@+id/main_date_of_birth"/>
        <TextView
            android:layout_width="wrap_content" android:layout_marginLeft="25dp"
            android:layout_height="wrap_content" 
            android:text="@string/med_rec_number_prompt"/>
        <TextView
            android:layout_width="wrap_content" android:layout_marginLeft="5dp"
            android:layout_height="wrap_content" android:id="@+id/main_med_rec_num"/>
    </LinearLayout>


</LinearLayout>

</android.support.v4.widget.DrawerLayout>