Android, appcompat v21, implement scrolling techni

问题:

In http://www.google.com/design/spec/patterns/scrolling-techniques.html described scrolling techniques. But I have not found details of how to implement it. I'm trying to implement "Flexible space with image" anyone have an example of this?

回答1:

I think this lib perfectly suits your need :

https://github.com/ksoichiro/Android-ObservableScrollView

It includes all the scrolling techniques described in the Google design specs and more. Moreover, it brings support for ListViews, GridViews, ScrollViews, RecyclerViews and WebViews.

回答2:

I think this blog post has what you're looking for. It offers a guide to make a layout similar to that (although you might have to add some code to color the app bar).

The grand idea behind this sort of "layout trick" is to implement a ScrollView with some sort of onScrollChanged listener. The aim is to make your Activity aware of scroll changes and then could transform the required elements.

Once you could get a sense of the scroll position (and changes) you could use that value as a base to apply color transformation (for the ActionBar's background) and to rescale the header text.

Hope this helps.

回答3:

Late but not least,

You need to you use Android Support Design Library v22 or Above. Specifically CoordinatorLayout with AppBar Layout and Toolbar.

<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">

     <! -- Your Scrollable View -->
    <android.support.v7.widget.RecyclerView
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            app:layout_behavior="@string/appbar_scrolling_view_behavior" />

    <android.support.design.widget.AppBarLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content">
   <android.support.v7.widget.Toolbar
                  ...
                  app:layout_scrollFlags="scroll|enterAlways">

        <android.support.design.widget.TabLayout
                  ...
                  app:layout_scrollFlags="scroll|enterAlways">
     </android.support.design.widget.AppBarLayout>
</android.support.design.widget.CoordinatorLayout>

as mentioned in android Developer Blogpost also described in Video by Ian Lake