我的一个客户最近想出了一个奇怪的灵感，我们真的很想将其集成到他的应用程序中
我正在努力实现这一目标，但我真的很困惑。有人可以指导我用动画实现这种过渡的步骤吗？
让我问一个具体的问题让你轻松回答
- 我们应该在这里使用哪些 fragment 或不同的 View 元素？
- 如何交互？比如当点击沙龙类别时，如何将该类别部分带到顶部并保持选中状态？
- 如何将它们也转换为寻呼机号码？
最佳答案
注意:完整的工作代码可在 https://github.com/mwajeeh/AnimationsPlayground 获得
这篇文章的更多解释:https://medium.com/p/implementing-complex-animations-in-android-full-working-code-41979cc2369e
卡片展开动画可以使用共享元素过渡来完成。我将为您提供足够的 Material 来开始实现打开类别和折叠寻呼机指示器。
我假设类别标题在 RecyclerView 中。当一个类别被点击时，打开带有共享元素转换的详细 Activity ，如下所示:
int firstVisibleItemPosition = layoutManager.findFirstVisibleItemPosition();
int lastVisibleItemPosition = layoutManager.findLastVisibleItemPosition();
List<Pair<View, String>> pairs = new ArrayList<Pair<View, String>>();
for (int i = firstVisibleItemPosition; i <= lastVisibleItemPosition; i++) {
ViewHolder holderForAdapterPosition = (ViewHolder) list.findViewHolderForAdapterPosition(i);
View itemView = holderForAdapterPosition.image;
pairs.add(Pair.create(itemView, "tab_" + i));
}
Bundle bundle = ActivityOptions.makeSceneTransitionAnimation(MainActivity.this, pairs.toArray(new Pair[]{})).toBundle();
//launch detail activity on tap
Intent intent = new Intent(context, DetailActivity.class);
context.startActivity(intent, bundle);
在下一个 Activity 中，我修改了 https://github.com/JakeWharton/ViewPagerIndicator/blob/master/library/src/com/viewpagerindicator/IconPageIndicator.java 的版本
只修改了这两种方法:
public void notifyDataSetChanged() {
mIconsLayout.removeAllViews();
IconPagerAdapter iconAdapter = (IconPagerAdapter) mViewPager.getAdapter();
int count = iconAdapter.getCount();
LayoutInflater inflater = LayoutInflater.from(getContext());
for (int i = 0; i < count; i++) {
View parent = inflater.inflate(R.layout.indicator, mIconsLayout, false);
ImageView view = (ImageView) parent.findViewById(R.id.icon);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
// must be same as off previous activity
view.setTransitionName("tab_" + i);
}
view.setImageResource(iconAdapter.getIconResId(i));
mIconsLayout.addView(parent);
}
if (mSelectedIndex > count) {
mSelectedIndex = count - 1;
}
setCurrentItem(mSelectedIndex);
requestLayout();
}
@Override
public void setCurrentItem(int item) {
if (mViewPager == null) {
throw new IllegalStateException("ViewPager has not been bound.");
}
mSelectedIndex = item;
mViewPager.setCurrentItem(item);
int tabCount = mIconsLayout.getChildCount();
for (int i = 0; i < tabCount; i++) {
View child = mIconsLayout.getChildAt(i);
boolean isSelected = (i == item);
child.setSelected(isSelected);
View foreground = child.findViewById(R.id.foreground);
if (isSelected) {
animateToIcon(item);
foreground.setBackgroundDrawable(ContextCompat.getDrawable(getContext(), R.drawable.fg_white));
} else {
foreground.setBackgroundDrawable(ContextCompat.getDrawable(getContext(), R.drawable.fg_gray));
}
}
}
并且在IconPageIndicator中增加了这个方法来支持指标的折叠:
public void collapse(float top, float total) {
//do not scale to 0
float newTop = top / 1.2F;
float scale = (total - newTop) / (float) total;
ViewCompat.setScaleX(this, scale);
ViewCompat.setScaleY(this, scale);
int tabCount = mIconsLayout.getChildCount();
float alpha = (total - top) / (float) total;
for (int i = 0; i < tabCount; i++) {
View parent = mIconsLayout.getChildAt(i);
View child = parent.findViewById(R.id.foreground);
ViewCompat.setAlpha(child, 1 - alpha);
}
}
在 DetailActivity 的 onCreate() 中，推迟过渡，直到布局指示器。
supportPostponeEnterTransition();
indicator.post(new Runnable() {
@Override
public void run() {
supportStartPostponedEnterTransition();
}
});
其他相关重要文件:
activity_detail.xml
<?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.design.widget.AppBarLayout
android:id="@+id/app_bar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@android:color/black"
app:elevation="0dp">
<android.support.design.widget.CollapsingToolbarLayout
android:id="@+id/toolbar_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:elevation="0dp"
app:layout_scrollFlags="scroll|exitUntilCollapsed">
<!--dummy view-->
<View
android:layout_width="match_parent"
android:layout_height="200dp"/>
<android.support.v7.widget.Toolbar
android:id="@+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="@android:color/transparent"
android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
app:elevation="0dp"
app:layout_collapseMode="pin"/>
</android.support.design.widget.CollapsingToolbarLayout>
</android.support.design.widget.AppBarLayout>
<com.example.mwajeeh.animations.IconPageIndicator
android:id="@+id/indicator"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:centered="true"
app:layout_behavior="com.example.mwajeeh.animations.CollapsingIndicatorBehaviour"/>
<!--add fragments in this view pager with RecyclerView as root and app:layout_behavior="@string/appbar_scrolling_view_behavior"-->
<android.support.v4.view.ViewPager
android:id="@+id/pager"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="@string/appbar_scrolling_view_behavior"/>
</android.support.design.widget.CoordinatorLayout>
CollapsingIndicatorBehaviour.java
import android.content.Context;
import android.support.annotation.NonNull;
import android.support.design.widget.AppBarLayout;
import android.support.design.widget.CoordinatorLayout;
import android.support.v4.view.WindowInsetsCompat;
import android.util.AttributeSet;
import android.view.View;
public class CollapsingIndicatorBehaviour extends ViewOffsetBehavior<IconPageIndicator> {
private static final String TAG = "CollapsingIndicatorBehaviour";
private WindowInsetsCompat lastInsets;
public CollapsingIndicatorBehaviour() {
}
public CollapsingIndicatorBehaviour(Context context, AttributeSet attrs) {
super(context, attrs);
}
@Override
public boolean layoutDependsOn(CoordinatorLayout parent, IconPageIndicator child, View dependency) {
return dependency instanceof AppBarLayout;
}
@Override
public boolean onDependentViewChanged(CoordinatorLayout parent, IconPageIndicator child, View dependency) {
//keep child centered inside dependency respecting android:fitsSystemWindows="true"
int systemWindowInsetTop = 0;
if (lastInsets != null) {
systemWindowInsetTop = lastInsets.getSystemWindowInsetTop();
}
int bottom = dependency.getBottom();
float center = (bottom - systemWindowInsetTop) / 2F;
float halfChild = child.getHeight() / 2F;
setTopAndBottomOffset((int) (center + systemWindowInsetTop - halfChild));
if (dependency instanceof AppBarLayout) {
float totalScrollRange = ((AppBarLayout) dependency).getTotalScrollRange();
child.collapse(-dependency.getTop(), totalScrollRange);
}
return true;
}
@NonNull
@Override
public WindowInsetsCompat onApplyWindowInsets(CoordinatorLayout coordinatorLayout, IconPageIndicator child, WindowInsetsCompat insets) {
lastInsets = insets;
return super.onApplyWindowInsets(coordinatorLayout, child, insets);
}
}
将 android.support.design.widget.ViewOffsetBehavior.java 和 android.support.design.widget.ViewOffsetHelper 从设计库复制到您的代码中。这些文件不是公开的，但我们需要它们才能让我们的行为发挥作用。
关于android - 如何连接多个 recyclerview 或 fragment 以显示动画，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/43542302/