带有片段和底部导航栏的Android FloatingActionButton [英] Android FloatingActionButton with fragment and bottom navigation bar

问题描述

我正在创建具有以下结构的android应用程序:

I'm creating an android app with the following structure:

• 主要活动的底部导航栏在3个不同的片段之间切换
• 其中两个片段将显示项目列表，并带有一个浮动操作按钮(FAB)以添加新项目
• 第三个片段将显示一些不同的东西，不需要FAB.

基于此，FAB似乎应该属于"列表片段，而不是主要活动.

Based on this, it seems like the FAB should "belong" to the list fragments, and not the main activity.

我目前有一个问题，就是FAB隐藏在底部导航栏的后面，例如这个问题.那里有一个很好的解决方案，但这取决于FAB与底部导航栏的布局是否相同.

I am currently have the problem that the FAB hides itself behind the bottom navigation bar, as in this question. There is a nice solution there, but it depends on the the FAB being in the same layout as the bottom navigation bar.

是否有一种方法可以使FAB不将自身隐藏在底部导航后面，而无需将FAB移至主要活动(这会破坏片段的模块化)?

Is there a way to get the FAB to not hide itself behind the bottom navigation, without moving the FAB up to the main activity (which breaks the modularity of the fragments)?

我的活动布局如下:

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout 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:id="@+id/container"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@+id/fragment_container"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>

    <android.support.design.widget.BottomNavigationView
        android:id="@+id/navigation"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginStart="0dp"
        android:layout_marginEnd="0dp"
        android:background="?android:attr/windowBackground"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_insetEdge="bottom"
        app:menu="@menu/navigation" />

</android.support.constraint.ConstraintLayout>

片段容器"被选定的片段替换，如下所示:

where the "fragment container" is replaced by the selected fragment as below:

    TodoListFragment fragment = new TodoListFragment();

    //if we were started with an intent, pass on any special arguments
    fragment.setArguments(getIntent().getExtras());

    getSupportFragmentManager().beginTransaction()
            .replace(R.id.fragment_container, fragment)
            .commit();

最后该片段的布局如下:

and finally the fragment has layout as below:

<?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"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <android.support.v7.widget.RecyclerView 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:id="@+id/list"
        android:name="..."
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_marginLeft="16dp"
        android:layout_marginRight="16dp"
        app:layoutManager="LinearLayoutManager"
        tools:context=".TodoListFragment"
        tools:listitem="@layout/fragment_todolist_item" />

    <android.support.design.widget.FloatingActionButton
        android:id="@+id/floatingActionButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="end|bottom"
        android:src="@drawable/ic_add_white_24dp"
        android:layout_margin="16dp" />

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

推荐答案

问题在于您的约束.您正在设置FrameLayout的高度以匹配父级.试试这个-

Problem is with your constraints. You are setting FrameLayout's height to match parent. Try this -

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@+id/fragment_container"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintBottom_toTopOf="@id/navigation"/>

这篇关于带有片段和底部导航栏的Android FloatingActionButton的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！