Android Studio 线性布局根本不显示

我已经得到这个来调试。我想我已经修复了 xml，但在设计器中根本没有显示任何内容。

我在想我可能有一些错误的标签或错误区域的东西？我对线性布局非常缺乏经验。

有人可以帮忙吗？

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

xmlns:tools="http://schemas.android.com/tools"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical"
tools:context=".MainActivity">

<LinearLayout android:id="@+id/members_list_screen"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical"
    android:visibility="gone" >
    
    <ListView android:id="@+id/members_list"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent" />
    
</LinearLayout>

<LinearLayout android:id="@+id/member_details_screen"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical"
    android:visibility="gone" >
    
    <LinearLayout android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal" >
    
        <TextView android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textAppearance="?android:attr/textAppearanceMedium"
            android:text="@string/name" />
        
        <TextView android:id="@+id/text_name"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textAppearance="?android:attr/textAppearanceMedium" />
    
    </LinearLayout>



    <LinearLayout android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal" >
    
        <TextView android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textAppearance="?android:attr/textAppearanceMedium"
            android:text="@string/birthday" />
        
        <TextView android:id="@+id/text_birthday"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textAppearance="?android:attr/textAppearanceMedium" />
        
    </LinearLayout>
    
    
    <LinearLayout android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal" >
    
        <TextView android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textAppearance="?android:attr/textAppearanceMedium"
            android:text="@string/gender" />
        
        <TextView android:id="@+id/text_gender"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textAppearance="?android:attr/textAppearanceMedium" />
    
    </LinearLayout>
            
    
    <LinearLayout android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal" >
    
        <TextView android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textAppearance="?android:attr/textAppearanceMedium"
            android:text="@string/twitter_id" />
        
        <TextView android:id="@+id/text_twitter_id"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textAppearance="?android:attr/textAppearanceMedium" />
    
    </LinearLayout>
        
    
    <LinearLayout android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal" >
    
        <TextView android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textAppearance="?android:attr/textAppearanceMedium"
            android:text="@string/youtube_id" />
        
        <TextView android:id="@+id/text_youtube_id"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textAppearance="?android:attr/textAppearanceMedium" />
        
    </LinearLayout>
    
    
    <LinearLayout android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal" >
    
        <TextView android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textAppearance="?android:attr/textAppearanceMedium"
            android:text="@string/name" />
        
        <TextView android:id="@+id/text_cspan_id"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textAppearance="?android:attr/textAppearanceMedium" />
        
    </LinearLayout>
    
</LinearLayout>