当 FloatingActionButton 锚定到 CollapsingToolbarLayout 时,它会在您向上滚动时消失,在您向下滚动到某个点后重新出现。我想知道您是否可以使用任何类型的 View 来做到这一点。在我的应用程序中,我试图将 ImageView 锚定到 CollapsingToolbarLayout,但它不会像 FloatingActionButton 那样消失。这是 XML 代码。
<android.support.design.widget.AppBarLayout
android:id="@+id/bar"
android:layout_width="match_parent"
android:layout_height="252dp"
android:fitsSystemWindows="true">
<android.support.design.widget.CollapsingToolbarLayout
android:id="@+id/collapsing_toolbar"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
app:contentScrim="?attr/colorPrimary"
app:expandedTitleMarginBottom="32dp"
app:expandedTitleMarginEnd="64dp"
app:expandedTitleMarginStart="48dp"
app:layout_scrollFlags="scroll|exitUntilCollapsed">
<ImageView
android:id="@+id/header"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@drawable/random"
android:fitsSystemWindows="true"
android:scaleType="centerCrop"
app:layout_collapseMode="parallax" />
<android.support.v7.widget.Toolbar
android:id="@+id/anim_toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
app:layout_collapseMode="pin"
app:popupTheme="@style/ThemeOverlay.AppCompat.Light" >
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"/>
</android.support.v7.widget.Toolbar>
</android.support.design.widget.CollapsingToolbarLayout>
</android.support.design.widget.AppBarLayout>
<android.support.v7.widget.RecyclerView
android:id="@+id/scrollableview"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="@string/appbar_scrolling_view_behavior" />
<com.example.sudarshan.testapp.MLRoundedImageView
android:layout_width="152dp"
android:layout_height="152dp"
app:layout_anchor="@+id/bar"
app:layout_anchorGravity="bottom|center"
android:id="@+id/circularImage"/>
</android.support.design.widget.CoordinatorLayout>
ImageView 被锚定,但它不会像 FAB 那样消失和重新出现。
最佳答案
View的这种消失和出现的行为只与FAB
(FloatingActionButton
)有关。
您应该查看类 FloatingActionButton
的源代码。
这是 Behavior
类中的方法,FloatingActionButton
的内部类负责行为。
@Override
public boolean onDependentViewChanged(CoordinatorLayout parent, FloatingActionButton child,
View dependency) {
if (dependency instanceof Snackbar.SnackbarLayout) {
updateFabTranslationForSnackbar(parent, child, dependency);
} else if (dependency instanceof AppBarLayout) {
// If we're depending on an AppBarLayout we will show/hide it automatically
// if the FAB is anchored to the AppBarLayout
updateFabVisibility(parent, (AppBarLayout) dependency, child);
}
return false;
}
编辑
您可以扩展类 FloatingActionButton
来实现我认为您需要的。
我已经扩展如下-
/**
* Sked Series, All rights Reserved
* Created by Sanjeet on 06-Jan-16.
*/
public class FloatingActionImageView extends FloatingActionButton {
public FloatingActionImageView(Context context) {
super(context);
}
public FloatingActionImageView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public FloatingActionImageView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
}
public static Bitmap getCroppedBitmap(Bitmap bmp, int radius) {
Bitmap sBmp;
if (bmp.getWidth() != radius || bmp.getHeight() != radius) {
float smallest = Math.min(bmp.getWidth(), bmp.getHeight());
float factor = smallest / radius;
sBmp = Bitmap.createScaledBitmap(bmp, (int) (bmp.getWidth() / factor), (int) (bmp.getHeight() / factor), false);
} else {
sBmp = bmp;
}
Bitmap output = Bitmap.createBitmap(radius, radius,
Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(output);
final Paint paint = new Paint();
final Rect rect = new Rect(0, 0, radius + 5, radius + 5);
paint.setAntiAlias(true);
paint.setFilterBitmap(true);
paint.setDither(true);
canvas.drawARGB(0, 0, 0, 0);
paint.setColor(Color.parseColor("#BAB399"));
canvas.drawCircle(radius / 2,
radius / 2, radius / 2, paint);
paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
canvas.drawBitmap(sBmp, rect, rect, paint);
return output;
}
@Override
protected void onDraw(@NonNull Canvas canvas) {
Drawable drawable = getDrawable();
if (drawable == null) {
return;
}
if (getWidth() == 0 || getHeight() == 0) {
return;
}
Bitmap b = ((BitmapDrawable) drawable).getBitmap();
Bitmap bitmap = null;
if (b != null) {
bitmap = b.copy(Bitmap.Config.ARGB_8888, true);
} else {
BitmapDrawable bitmapDrawable = null;
if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.LOLLIPOP) {
bitmapDrawable = ((BitmapDrawable) getResources().getDrawable(com.sked.dd.R.drawable.ic_menu_gallery, null));
} else {
bitmapDrawable = ((BitmapDrawable) getResources().getDrawable(com.sked.dd.R.drawable.ic_menu_gallery));
}
if (bitmapDrawable != null) {
bitmap = bitmapDrawable.getBitmap();
}
}
int w = getWidth();
Bitmap roundBitmap = getCroppedBitmap(bitmap, w);
canvas.drawBitmap(roundBitmap, 0, 0, null);
}
}
这是输出-
关于android - 将 ImageView 锚定到折叠工具栏,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/34632497/