判断是否是新旧包
public boolean isNewUserForVersionCode(Context context) {
/**
* 获取指定应用程序 ApplicationInfo
* 参数一对应应用程序的包名
* 参数二 应用程序对应的标识 通常为 0
*/
try {
PackageInfo packageInfo = context.getPackageManager().getPackageInfo(context.getPackageName(), 0);
long firstInstallTime = packageInfo.firstInstallTime;
long lastUpdateTime = packageInfo.lastUpdateTime;
String versionName = packageInfo.versionName;
if (firstInstallTime == lastUpdateTime && versionName.contains(mVersionName)) {
return true;
}
} catch (PackageManager.NameNotFoundException e) {
e.printStackTrace();
}
return false;
}
RecycleView 做一个上下滑动顶部工具类显示与隐藏的动效
-
如下为效果图
- 1.首先布局文件的RecycleView和顶部的条目要顶端对齐，我这里就是RecycleView和顶部的三个选项的顶端对齐，也就是RecycleView和RadioGroup对齐了
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.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:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#F0F2F8"
android:fitsSystemWindows="true"
tools:context=".activity.FamousAttractionsActivity">
<androidx.constraintlayout.widget.ConstraintLayout
android:id="@+id/cl_famous_attractions_title"
android:layout_width="match_parent"
android:layout_height="56dp"
android:background="@color/white"
app:layout_constraintTop_toTopOf="parent">
<ImageView
android:id="@+id/iv_back"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="@dimen/ayp_8dp"
android:background="@drawable/ripple_icon_circle"
android:contentDescription="@null"
android:scaleType="centerCrop"
android:src="@drawable/ic_back_black"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<TextView
android:id="@+id/tv_page_title"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginHorizontal="8dp"
android:ellipsize="end"
android:fontFamily="@font/kanit_semibold"
android:gravity="start"
android:lines="1"
android:text="@string/famous_attractions"
android:textColor="@color/black_253A"
android:textSize="18sp"
app:layout_constraintBottom_toBottomOf="@id/iv_back"
app:layout_constraintEnd_toStartOf="@id/iv_famous_favorite"
app:layout_constraintStart_toEndOf="@id/iv_back"
app:layout_constraintTop_toTopOf="@id/iv_back" />
<ImageView
android:id="@+id/iv_famous_favorite"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginEnd="8dp"
android:background="@drawable/ripple_icon_circle"
android:src="@drawable/ic_famous_favorite"
app:layout_constraintBottom_toBottomOf="@id/iv_back"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toTopOf="@id/iv_back" />
</androidx.constraintlayout.widget.ConstraintLayout>
<View
android:id="@+id/view_famous_line"
android:layout_width="match_parent"
android:layout_height="2px"
android:background="@color/gray_famous_line"
app:layout_constraintTop_toBottomOf="@id/cl_famous_attractions_title" />
<RadioGroup
android:id="@+id/rg_famous_attractions"
android:layout_width="match_parent"
android:layout_height="@dimen/dp_40"
android:background="@color/white"
android:orientation="horizontal"
android:paddingHorizontal="@dimen/dp16"
android:paddingVertical="5dp"
app:layout_constraintTop_toBottomOf="@id/view_famous_line">
<RadioButton
android:id="@+id/rb_famous_all"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1"
android:background="@drawable/ripple_white_20r"
android:button="@null"
android:gravity="center"
android:text="@string/all"
android:textColor="@color/selector_famous_attraction"
android:textSize="@dimen/sp_14" />
<RadioButton
android:id="@+id/rb_famous_seven_wonders"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1"
android:background="@drawable/ripple_white_20r"
android:button="@null"
android:gravity="center"
android:text="@string/seven_wonders"
android:textColor="@color/selector_famous_attraction"
android:textSize="@dimen/sp_14" />
<RadioButton
android:id="@+id/rb_famous_regions"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1"
android:background="@drawable/ripple_white_20r"
android:button="@null"
android:gravity="center"
android:text="@string/regions"
android:textColor="@color/selector_famous_attraction"
android:textSize="@dimen/sp_14" />
</RadioGroup>
<androidx.viewpager2.widget.ViewPager2
android:layout_width="match_parent"
android:layout_height="0dp"
app:layout_constraintTop_toBottomOf="@id/view_famous_line"
app:layout_constraintBottom_toBottomOf="parent"
android:id="@+id/vp_famous_attractions"/>
</androidx.constraintlayout.widget.ConstraintLayout>
- 2.写一个显示与隐藏的动效,其中，title就是你的title的高度，我这里，就是RadioGroup的高度
private var mAnimatorTitle: Animator? = null
private var mAnimatorContent: Animator? = null
private var mAnimatorTitleAlpha: Animator? = null
private fun showHideTitleBar(tag: Boolean) {
if (mAnimatorTitle != null && mAnimatorTitle!!.isRunning) {
mAnimatorTitle!!.cancel()
}
if (mAnimatorContent != null && mAnimatorContent!!.isRunning) {
mAnimatorContent!!.cancel()
}
val titleView = (activity as FamousAttractionsActivity?)!!.titleView
if (tag) {
mAnimatorTitle =
ObjectAnimator.ofFloat(titleView, "translationY", titleView.translationY, 0f)
mAnimatorTitleAlpha = ObjectAnimator.ofFloat(titleView, "alpha", 0f, 1f)
mAnimatorContent = ObjectAnimator.ofFloat(
mBinding.rvFamousAttractions,
"translationY",
mBinding.rvFamousAttractions.translationY,
titleView.height.toFloat()
)
} else {
mAnimatorTitle = ObjectAnimator.ofFloat(
titleView,
"translationY",
titleView.translationY,
-titleView.height.toFloat()
)
mAnimatorTitleAlpha = ObjectAnimator.ofFloat(titleView, "alpha", 1f, 0f)
mAnimatorContent = ObjectAnimator.ofFloat(
mBinding.rvFamousAttractions,
"translationY",
mBinding.rvFamousAttractions.translationY,
0f
)
}
mAnimatorTitle?.start()
mAnimatorTitleAlpha?.start()
mAnimatorContent?.start()
}
mBinding.rvFamousAttractions.addOnScrollListener(object :
RecyclerView.OnScrollListener() {
private var scrollDist = 0
private var isVisible = true
override fun onScrolled(recyclerView: RecyclerView, dx: Int, dy: Int) {
super.onScrolled(recyclerView, dx, dy)
if (isVisible && scrollDist > 50) {
// 上滑隐藏
isVisible = false
scrollDist = 0
// 执行隐藏动画或其他操作
showHideTitleBar(false)
} else if (!isVisible && scrollDist < -50) {
// 下滑显示
isVisible = true
scrollDist = 0
// 执行显示动画或其他操作
showHideTitleBar(true)
}
if (isVisible && dy > 0 || !isVisible && dy < 0) {
scrollDist += dy
}
}
})
showHideTitleBar(true)
- RecycleView 这个解决notifyItemChanged闪一下的问题
(mBinding.rvFamousAttractions.itemAnimator as? SimpleItemAnimator)?.supportsChangeAnimations = false
- 6.如何通过文件名称获取对应的Drawable或者String
fun Context.getDrawableResourceId(name: String) :Int{
return resources.getIdentifier(name, "drawable", packageName)
}
fun Context.getStringResource(name: String) :Int{
return resources.getIdentifier(name, "string", packageName)
}
