问题
I have been adding a navigation drawer to one of my apps, and I started to wonder whether or not it would be better to switch from using a ListView to multiple TextViews for the navigation drawer list items. Looking at the Google Design Guidelines on Navigation Drawer content (specifically the section on 'Scrolling'), I noticed that it may look nicer with multiple TextViews.
At the moment, I am using a ListView and ImageView in my navigation drawer (it looks a little like this. However, when I scroll in my navigation drawer (I do this by turning my device landscape as there are not enough items in my list yet), only the ListView scrolls, and the ImageView stays as it is. I want it to be able to scoll more like this, where the ImageView is also scrolled with the ListView.
Additionally, I found that my ListView in my navigation drawer does not have the ripple effects as shown in this image although other ListViews in my other Activitys and Fragments do.
What are the issues I am facing and how could I go about resolving these?
Update:
In Google's I/O App (2014), there seems to be a LinearLayout at the bottom of the navigation drawer layout which I think is responsible for the list of items shown. Could someone explain how this would work?
回答1:
only the ListView scrolls, and the ImageView stays as it is
It sounds like your drawer contains an ImageView at the top and then a ListView follows. With this configuration only the ListView will scroll (because it's the only view that's scrollable).
You need to add the ImageView as a header which is always at the beginning of the list. As one of the comments suggested, do listView.addHeaderView.
there seems to be a LinearLayout at the bottom of the navigation drawer layout which I think is responsible for the list of items shown. Could someone explain how this would work?
They use the LinearLayout as a container to hold all the TextViews:
private void createNavDrawerItems() {
mDrawerItemsListContainer = (ViewGroup) findViewById(R.id.navdrawer_items_list);
...
int i = 0;
for (int itemId : mNavDrawerItems) {
mNavDrawerItemViews[i] = makeNavDrawerItem(itemId, mDrawerItemsListContainer);
mDrawerItemsListContainer.addView(mNavDrawerItemViews[i]);
++i;
}
}
I believe the reason they use a LinearLayout and inflate all the items programmatically is to be able to use separator items easily:
private View makeNavDrawerItem(final int itemId, ViewGroup container) {
...
if (itemId == NAVDRAWER_ITEM_SEPARATOR) {
layoutToInflate = R.layout.navdrawer_separator;
} else if (itemId == NAVDRAWER_ITEM_SEPARATOR_SPECIAL) {
layoutToInflate = R.layout.navdrawer_separator;
} else {
layoutToInflate = R.layout.navdrawer_item;
}
...
return view;
}
In a ListView you'd have to create a separate item type and use the divider's layout there, which could possibly get more cumbersome.
At first glance, however, this code just seems to be re-inventing the wheel as all of this is possible with a ListView.
回答2:
As of 29th May 2015 (after Google I/O 2015), you can use the Android Design Support Library to add a NavigationView to your app(s). The Android Developer Blogspot article states the following:
Navigation View
The navigation drawer can be an important focal point for identity and navigation within your app and consistency in the design here can make a considerable difference in how easy your app is to navigate, particularly for first time users. NavigationView makes this easier by providing the framework you need for the navigation drawer as well as the ability to inflate your navigation items through a menu resource.
...
You can then start using the Design library with a single new dependency:
compile 'com.android.support:design:22.2.0'...
The Design library, AppCompat, and all of the Android Support Library are important tools in providing the building blocks needed to build a modern, great looking Android app without building everything from scratch.
回答3:
Implementing scrollable Navigation Drawer using android.support.v4.widget.DrawerLayout and NavigationView could be even simpler than it is described at: http://android-developers.blogspot.ru/2015/05/android-design-support-library.html
That article suggests adding each element of your application's Navigation Drawer as a Menu Item. This is cool and definitely a way to go for most of developers. But what if you already has a Navigation Drawer implemented inside e.g. Linear Layout?
It appears that you can easily make your old good layout scrollable: just set it as a "app:headerLayout" of the NavigationView. No more changes are needed! So, in a final solution you will have:
A layout of your Activity, similar to the above blog post, but without an "app:menu="@menu/drawer" attribute e.g. this:
<android.support.v4.widget.DrawerLayout
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:fitsSystemWindows="true">
<!-- your content layout -->
<android.support.design.widget.NavigationView
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_gravity="start"
app:headerLayout="@layout/drawer_header"
/>
</android.support.v4.widget.DrawerLayout>
And a layout for all your old Drawer content in the "drawer_header.xml" file, migrated without any changes to this scrollable Drawer, E.g. this:
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:choiceMode="singleChoice"
android:orientation="vertical">
<TextView
android:id="@+id/myFirstButton"
android:onClick="onMyFirstButtonClick"
android:text="@string/my_first_button_title"/>
<TextView
android:id="@+id/goToTheTopButton"
android:onClick="onGoToTheTopButtonClick"
android:text="@string/go_to_the_top_title"/>
<View style="@style/Divider"/>
<!-- Some other "menu items" -->
</LinearLayout>
For full working example see this activity layout: https://github.com/andstatus/andstatus/blob/master/app/src/main/res/layout/timeline.xml and this commit, where I migrated to a scrollable Navigation Drawer: https://github.com/andstatus/andstatus/commit/a80b299de714bdd65cacb138ffb31adc3ea23a98
来源：https://stackoverflow.com/questions/30084530/best-way-of-implementing-a-scrolling-navigation-drawer