问题描述
我想要的是，当用户单击ListView中的列表项时，它会转换为整个活动(如下面的示例所示)，但是我找不到找到说明这一点的教程，实际上，我不知道怎么称呼这个运动.
What I want is that when the user clicks a list item in a ListView, it converts to a whole activity (as you can see in the following example), but I was not able to find a tutorial explaining this and, actually, I do not know how this movement is called.
换句话说，我想要实现的是:
In other words, what I want to achieve is:
-
单击时增加列表项的高度(如右图所示)
Increase List Item elevation when it is clicked (as you can see in the right gif)
扩展列表项并将其转换为下一个片段/活动布局，其中包含有关单击项的详细信息
Expand and transform list item to the next fragment/activity layout that contains detailed information about the clicked item
我尝试了很多转换，但是没有运气.谁能帮我完成这个任务?
I have tried a lot of transitions but with no luck. Can anyone help me out to accomplish this?
推荐答案
我构建了一个小型示例应用程序，该应用程序在两个活动之间进行了转换，并具有预期的效果:
I build a small sample application that transitions between two activities with the desired effect:
但是，提供的gif中的过渡效果略有不同.这左侧gif中的transition会将list元素转换为第二个活动的内容区域(工具栏保持原位).在右侧的gif中，转换将列表元素转换为第二个活动的完整屏幕.以下代码在左侧gif中提供了效果.但是，应该可以对解决方案进行少量修改，以实现正确的gif过渡.
However the transitions in the provided gifs are slightly different. Thetransition in the gif on the left side transitions the list element into the content area of the second activity (Toolbar stays in place). In the gif on the right side the transition transforms the list element into the complete screen of the second activity. The following code provides the effect in the left gif. However it should be possible to adapt the solution with minor modifications to achieve the transition in the right gif.
请注意，这仅适用于棒棒糖.但是，可以在旧设备上模拟不同的效果.此外，提供的代码的唯一目的是展示如何实现.不要在您的应用程序中直接使用它.
Note this only works on Lollipop. However it is possible to mock a different effect on older devices.Furthermore the sole purpose of the provided code is to show how it could be done. Don't use this directly in your app.
MainActivity:
MainActivity:
public class MainActivity extends AppCompatActivity {
MyAdapter myAdapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
setSupportActionBar((Toolbar) findViewById(R.id.toolbar));
ListView listView = (ListView) findViewById(R.id.list_view);
myAdapter = new MyAdapter(this, 0, DataSet.get());
listView.setAdapter(myAdapter);
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, final View view, final int position, long id) {
startTransition(view, myAdapter.getItem(position));
}
});
}
private void startTransition(View view, Element element) {
Intent i = new Intent(MainActivity.this, DetailActivity.class);
i.putExtra("ITEM_ID", element.getId());
Pair<View, String>[] transitionPairs = new Pair[4];
transitionPairs[0] = Pair.create(findViewById(R.id.toolbar), "toolbar"); // Transition the Toolbar
transitionPairs[1] = Pair.create(view, "content_area"); // Transition the content_area (This will be the content area on the detail screen)
// We also want to transition the status and navigation bar barckground. Otherwise they will flicker
transitionPairs[2] = Pair.create(findViewById(android.R.id.statusBarBackground), Window.STATUS_BAR_BACKGROUND_TRANSITION_NAME);
transitionPairs[3] = Pair.create(findViewById(android.R.id.navigationBarBackground), Window.NAVIGATION_BAR_BACKGROUND_TRANSITION_NAME);
Bundle b = ActivityOptionsCompat.makeSceneTransitionAnimation(MainActivity.this, transitionPairs).toBundle();
ActivityCompat.startActivity(MainActivity.this, i, b);
}
}
activity_main.xml:
activity_main.xml:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<android.support.v7.widget.Toolbar
android:id="@+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="@color/colorPrimary"
android:transitionName="toolbar" />
<ListView
android:id="@+id/list_view"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</LinearLayout>
DetailActivity:
DetailActivity:
public class DetailActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_detail);
setSupportActionBar((Toolbar) findViewById(R.id.toolbar));
long elementId = getIntent().getLongExtra("ITEM_ID", -1);
Element element = DataSet.find(elementId);
((TextView) findViewById(R.id.title)).setText(element.getTitle());
((TextView) findViewById(R.id.description)).setText(element.getDescription());
// if we transition the status and navigation bar we have to wait till everything is available
TransitionHelper.fixSharedElementTransitionForStatusAndNavigationBar(this);
// set a custom shared element enter transition
TransitionHelper.setSharedElementEnterTransition(this, R.transition.detail_activity_shared_element_enter_transition);
}
}
activity_detail.xml:
activity_detail.xml:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<android.support.v7.widget.Toolbar
android:id="@+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="@color/colorPrimary"
android:transitionName="toolbar" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#abc"
android:orientation="vertical"
android:paddingBottom="200dp"
android:transitionName="content_area"
android:elevation="10dp">
<TextView
android:id="@+id/title"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
<TextView
android:id="@+id/description"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
</LinearLayout>
</LinearLayout>
detail_activity_shared_element_enter_transition.xml(/res/transition/):
detail_activity_shared_element_enter_transition.xml (/res/transition/):
<?xml version="1.0" encoding="utf-8"?>
<transitionSet xmlns:android="http://schemas.android.com/apk/res/android"
android:transitionOrdering="together">
<changeBounds/>
<changeTransform/>
<changeClipBounds/>
<changeImageTransform/>
<transition class="my.application.transitions.ElevationTransition"/>
</transitionSet>
my.application.transitions.ElevationTransition:
my.application.transitions.ElevationTransition:
@TargetApi(Build.VERSION_CODES.LOLLIPOP)
public class ElevationTransition extends Transition {
private static final String PROPNAME_ELEVATION = "my.elevation:transition:elevation";
public ElevationTransition() {
}
public ElevationTransition(Context context, AttributeSet attrs) {
super(context, attrs);
}
@Override
public void captureStartValues(TransitionValues transitionValues) {
captureValues(transitionValues);
}
@Override
public void captureEndValues(TransitionValues transitionValues) {
captureValues(transitionValues);
}
private void captureValues(TransitionValues transitionValues) {
Float elevation = transitionValues.view.getElevation();
transitionValues.values.put(PROPNAME_ELEVATION, elevation);
}
@Override
public Animator createAnimator(ViewGroup sceneRoot, TransitionValues startValues, TransitionValues endValues) {
if (startValues == null || endValues == null) {
return null;
}
Float startVal = (Float) startValues.values.get(PROPNAME_ELEVATION);
Float endVal = (Float) endValues.values.get(PROPNAME_ELEVATION);
if (startVal == null || endVal == null || startVal.floatValue() == endVal.floatValue()) {
return null;
}
final View view = endValues.view;
ValueAnimator a = ValueAnimator.ofFloat(startVal, endVal);
a.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
@Override
public void onAnimationUpdate(ValueAnimator animation) {
view.setElevation((float)animation.getAnimatedValue());
}
});
return a;
}
}
TransitionHelper:
TransitionHelper:
public class TransitionHelper {
public static void fixSharedElementTransitionForStatusAndNavigationBar(final Activity activity) {
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP)
return;
final View decor = activity.getWindow().getDecorView();
if (decor == null)
return;
activity.postponeEnterTransition();
decor.getViewTreeObserver().addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {
@TargetApi(Build.VERSION_CODES.LOLLIPOP)
@Override
public boolean onPreDraw() {
decor.getViewTreeObserver().removeOnPreDrawListener(this);
activity.startPostponedEnterTransition();
return true;
}
});
}
public static void setSharedElementEnterTransition(final Activity activity, int transition) {
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP)
return;
activity.getWindow().setSharedElementEnterTransition(TransitionInflater.from(activity).inflateTransition(transition));
}
}
那么这里有什么不同的部分:我们有两个活动.在过渡期间，将在活动之间过渡四个视图.
So what are the different parts here:We have two activities. During the transition four views are transitioned between the activities.
-
工具栏:就像在左gif中一样，工具栏不会随其余内容一起移动.
Toolbar: like in the left gif the toolbar doesn't move with the rest of the content.
ListView元素View->成为DetailActivity的内容视图
ListView element View -> becomes the content view of the DetailActivity
StatusBar和NavigationBar背景:如果不将这些视图添加到过渡视图集中，它们将在过渡期间淡出并返回.但是，这需要延迟输入转换(请参见:TransitionHelper.fixSharedElementTransitionForStatusAndNavigationBar)
StatusBar and NavigationBar Background: If we don't add these views to the set of transitioned views they will fade out and back in during the transition. This however requires to delay the enter transition (see: TransitionHelper.fixSharedElementTransitionForStatusAndNavigationBar)
在MainActivity中，已转换的视图将添加到用于启动DetailActivity的捆绑包中.此外，在两个活动中都需要将转换后的视图命名为(transitionName).这可以在布局xml中以及以编程方式完成.
In the MainActivity the transitioned views are added to the Bundle that is used to start the DetailActivity. Furthermore the transitioned views need to be named (transitionName) in both activities. This can be done in the layout xml as well as programatically.
在共享元素过渡期间使用的默认过渡集会影响视图的不同方面(例如:视图范围-请参见 2 ).但是，视图高程的差异不会显示动画.这就是为什么提出的解决方案使用自定义ElevationTransition的原因.
The default set of transitions, that is used during the shared element transition, affects different aspects of the view(for example: view bounds - see 2). However differences in the elevation of a view are not animated. This is why the presented solution utilizes the custom ElevationTransition.
这篇关于Android-如何创建从列表视图中的项到整个活动的过渡?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！