浮动动作按钮滚动内容

Question

我在布局中实现了一个浮动动作按钮。问题是当我的布局中有太多数据时，按钮不能保持在同一位置，它会滚动到布局的底部。我需要和Gmail收件箱一样的功能：无论数据如何，总是可以访问的浮动按钮。

这是我的代码，以显示该按钮

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

    <include 
     android:id="@+id/frgOffline" 
     android:visibility="gone" 
     layout="@layout/frg_offline"/> 


    <android.support.v7.widget.CardView xmlns:card_view="http://schemas.android.com/apk/res-auto" card_view:cardBackgroundColor="@android:color/white" 
     android:layout_width="match_parent" 
     android:layout_height="match_parent" 
     android:layout_marginRight="5dp" 
     android:layout_marginLeft="5dp" 
     android:layout_marginBottom="7dp" 
     android:layout_marginTop="7dp" 
     android:gravity="center_vertical|left"> 

      <LinearLayout 
       android:visibility="gone" 
       android:layout_width="match_parent" 
       android:layout_height="match_parent" 
       android:gravity="center_horizontal" 
       android:orientation="vertical"> 

       <TextView 
        android:layout_height="wrap_content" 
        android:layout_width="wrap_content" 
        android:layout_marginTop="25dp" 
        android:textAppearance="?android:attr/textAppearanceSmall" 
        android:text="text" 
        android:layout_marginBottom="15dp" 
        android:textStyle="bold"/> 

       <TextView 
        android:layout_width="match_parent" 
        android:layout_height="wrap_content" 
        android:padding="15dp" 
        android:layout_margin="5dp" 
        android:textAppearance="?android:attr/textAppearanceSmall"/> 

       <com.exampleapp.expandiblelist 
        android:id="@+id/expListaResultado" 
        android:groupIndicator="@null" 
        android:layout_height="fill_parent" 
        android:transcriptMode="disabled" 
        android:layout_width="match_parent"/> 
      </LinearLayout> 

     <android.support.design.widget.FloatingActionButton 
      android:id="@+id/btnNueva" 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:elevation="4dp" 
      android:layout_marginBottom="5dp" 
      android:layout_marginLeft="5dp" 
      android:src="@drawable/ic_nuevo" 
      android:layout_gravity="bottom|right" 
      app:backgroundTint="@color/blue"/> 

     </android.support.v7.widget.CardView> 
</LinearLayout> 

这是怎么回事？

感谢您的帮助！

Answer 1

你可以看到这个代码，这将很好地工作，你

<?xml version="1.0" encoding="utf-8"?> 
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    xmlns:app="http://schemas.android.com/apk/res-auto" 
    android:orientation="vertical"> 

<android.support.v7.widget.CardView xmlns:card_view="http://schemas.android.com/apk/res-auto" card_view:cardBackgroundColor="@android:color/white" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    android:layout_marginRight="5dp" 
    android:layout_marginLeft="5dp" 
    android:layout_marginBottom="7dp" 
    android:layout_marginTop="7dp" 
    android:gravity="center_vertical|left"> 

    <LinearLayout 
     android:visibility="gone" 
     android:layout_width="match_parent" 
     android:layout_height="match_parent" 
     android:gravity="center_horizontal" 
     android:orientation="vertical"> 

     <TextView 
      android:layout_height="wrap_content" 
      android:layout_width="wrap_content" 
      android:layout_marginTop="25dp" 
      android:textAppearance="?android:attr/textAppearanceSmall" 
      android:text="text" 
      android:layout_marginBottom="15dp" 
      android:textStyle="bold"/> 

     <TextView 
      android:layout_width="match_parent" 
      android:layout_height="wrap_content" 
      android:padding="15dp" 
      android:layout_margin="5dp" 
      android:textAppearance="?android:attr/textAppearanceSmall"/> 

     <com.exampleapp.expandiblelist 
      android:id="@+id/expListaResultado" 
      android:groupIndicator="@null" 
      android:layout_height="fill_parent" 
      android:transcriptMode="disabled" 
      android:layout_width="match_parent"/> 
    </LinearLayout> 



</android.support.v7.widget.CardView> 
<android.support.design.widget.FloatingActionButton 
    android:id="@+id/btnNueva" 
    android:layout_width="48dp" 
    android:layout_height="48dp" 
    android:elevation="4dp" 
    android:layout_marginBottom="16dp" 
    android:layout_marginLeft="5dp" 
    android:src="@mipmap/ic_launcher" 
    android:layout_alignParentBottom="true" 
    android:layout_alignParentRight="true" 
    android:layout_marginRight="16dp" 
    /> 
</RelativeLayout> 

Answer 2

需要coordinatorlayout这个 试试这个，这可能有助于

<?xml version="1.0" encoding="utf-8"?> 
<android.support.design.widget.CoordinatorLayout 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:layout_width="match_parent" 
    android:layout_height="match_parent" 
    android:fitsSystemWindows="true" 
    tools:context="info.androidhive.fab.MainActivity"> 

    <android.support.design.widget.AppBarLayout 
     android:layout_width="match_parent" 
     android:layout_height="wrap_content" 
     android:theme="@style/AppTheme.AppBarOverlay"> 

     <android.support.v7.widget.Toolbar 
      android:id="@+id/toolbar" 
      android:layout_width="match_parent" 
      android:layout_height="?attr/actionBarSize" 
      android:background="?attr/colorPrimary" 
      app:popupTheme="@style/AppTheme.PopupOverlay" /> 

    </android.support.design.widget.AppBarLayout> 

    <include layout="@layout/content_main" /> 

    <android.support.design.widget.FloatingActionButton 
     android:id="@+id/fab" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:layout_gravity="bottom|end" 
     android:layout_margin="@dimen/fab_margin" 
     android:src="@android:drawable/ic_dialog_email" /> 

</android.support.design.widget.CoordinatorLayout> 

在content_main布局

把所有必要的代码...