我的解决方案
我有一个与您相同的场景需要实现,所以我从狗的例子开始,并进行了一些更改,使其完全按照您的要求工作。我的代码可以在该项目的分支中找到,请参见https://github.com/hanscappelle/CoordinatorBehaviorExample
最重要的更改在布局中:
<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/main.appbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
>
<android.support.design.widget.CollapsingToolbarLayout
android:id="@+id/main.collapsing"
android:layout_width="match_parent"
android:layout_height="@dimen/expanded_toolbar_height"
app:layout_scrollFlags="scroll|exitUntilCollapsed|snap"
>
<FrameLayout
android:id="@+id/main.framelayout.title"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="bottom"
>
<LinearLayout
android:id="@+id/main.linearlayout.title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="bottom|center_horizontal"
android:orientation="vertical"
android:paddingBottom="@dimen/spacing_small"
>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:gravity="bottom|center_horizontal"
android:text="@string/tequila_name"
android:textColor="@android:color/white"
android:textSize="@dimen/textsize_xlarge"
/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:layout_marginTop="@dimen/spacing_xxsmall"
android:text="@string/tequila_tagline"
android:textColor="@android:color/white"
/>
</LinearLayout>
</FrameLayout>
</android.support.design.widget.CollapsingToolbarLayout>
</android.support.design.widget.AppBarLayout>
<android.support.v4.widget.NestedScrollView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scrollbars="none"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
>
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:lineSpacingExtra="@dimen/spacing_xsmall"
android:padding="@dimen/spacing_normal"
android:text="@string/lorem"
android:textSize="@dimen/textsize_medium"
/>
</android.support.v4.widget.NestedScrollView>
<android.support.v7.widget.Toolbar
android:id="@+id/main.toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="@color/primary"
app:layout_anchor="@id/main.collapsing"
app:theme="@style/ThemeOverlay.AppCompat.Dark"
app:title=""
>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:orientation="horizontal"
>
<Space
android:layout_width="@dimen/image_final_width"
android:layout_height="@dimen/image_final_width"
/>
<TextView
android:id="@+id/main.textview.title"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_marginLeft="8dp"
android:gravity="center_vertical"
android:text="@string/tequila_title"
android:textColor="@android:color/white"
android:textSize="@dimen/textsize_large"
/>
</LinearLayout>
</android.support.v7.widget.Toolbar>
<de.hdodenhof.circleimageview.CircleImageView
android:layout_width="@dimen/image_width"
android:layout_height="@dimen/image_width"
android:layout_gravity="top|center_horizontal"
android:layout_marginTop="@dimen/spacing_normal"
android:src="@drawable/ninja"
app:border_color="@android:color/white"
app:border_width="@dimen/border_width"
app:finalHeight="@dimen/image_final_width"
app:finalXPosition="@dimen/spacing_small"
app:finalYPosition="@dimen/spacing_small"
app:finalToolbarHeight="?attr/actionBarSize"
app:layout_behavior="saulmm.myapplication.AvatarImageBehavior"
/>
</android.support.design.widget.CoordinatorLayout>
我优化了AvatarImageBehaviour类,仅将头像从原始位置移动到属性配置的位置。因此,如果您想要图像从另一个位置移动,请在布局中移动它。这样做时,请确保AppBarLayout仍然是其兄弟,否则代码中将找不到它。
package saulmm.myapplication;
import android.content.Context;
import android.content.res.TypedArray;
import android.support.design.widget.AppBarLayout;
import android.support.design.widget.CoordinatorLayout;
import android.util.AttributeSet;
import android.view.View;
import de.hdodenhof.circleimageview.CircleImageView;
public class AvatarImageBehavior extends CoordinatorLayout.Behavior<CircleImageView> {
// calculated from given layout
private int startXPositionImage;
private int startYPositionImage;
private int startHeight;
private int startToolbarHeight;
private boolean initialised = false;
private float amountOfToolbarToMove;
private float amountOfImageToReduce;
private float amountToMoveXPosition;
private float amountToMoveYPosition;
// user configured params
private float finalToolbarHeight, finalXPosition, finalYPosition, finalHeight;
public AvatarImageBehavior(
final Context context,
final AttributeSet attrs) {
if (attrs != null) {
TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.AvatarImageBehavior);
finalXPosition = a.getDimension(R.styleable.AvatarImageBehavior_finalXPosition, 0);
finalYPosition = a.getDimension(R.styleable.AvatarImageBehavior_finalYPosition, 0);
finalHeight = a.getDimension(R.styleable.AvatarImageBehavior_finalHeight, 0);
finalToolbarHeight = a.getDimension(R.styleable.AvatarImageBehavior_finalToolbarHeight, 0);
a.recycle();
}
}
@Override
public boolean layoutDependsOn(
final CoordinatorLayout parent,
final CircleImageView child,
final View dependency) {
return dependency instanceof AppBarLayout; // change if you want another sibling to depend on
}
@Override
public boolean onDependentViewChanged(
final CoordinatorLayout parent,
final CircleImageView child,
final View dependency) {
// make child (avatar) change in relation to dependency (toolbar) in both size and position, init with properties from layout
initProperties(child, dependency);
// calculate progress of movement of dependency
float currentToolbarHeight = startToolbarHeight + dependency.getY(); // current expanded height of toolbar
// don't go below configured min height for calculations (it does go passed the toolbar)
currentToolbarHeight = currentToolbarHeight < finalToolbarHeight ? finalToolbarHeight : currentToolbarHeight;
final float amountAlreadyMoved = startToolbarHeight - currentToolbarHeight;
final float progress = 100 * amountAlreadyMoved / amountOfToolbarToMove; // how much % of expand we reached
// update image size
final float heightToSubtract = progress * amountOfImageToReduce / 100;
CoordinatorLayout.LayoutParams lp = (CoordinatorLayout.LayoutParams) child.getLayoutParams();
lp.width = (int) (startHeight - heightToSubtract);
lp.height = (int) (startHeight - heightToSubtract);
child.setLayoutParams(lp);
// update image position
final float distanceXToSubtract = progress * amountToMoveXPosition / 100;
final float distanceYToSubtract = progress * amountToMoveYPosition / 100;
float newXPosition = startXPositionImage - distanceXToSubtract;
//newXPosition = newXPosition < endXPosition ? endXPosition : newXPosition; // don't go passed end position
child.setX(newXPosition);
child.setY(startYPositionImage - distanceYToSubtract);
return true;
}
private void initProperties(
final CircleImageView child,
final View dependency) {
if (!initialised) {
// form initial layout
startHeight = child.getHeight();
startXPositionImage = (int) child.getX();
startYPositionImage = (int) child.getY();
startToolbarHeight = dependency.getHeight();
// some calculated fields
amountOfToolbarToMove = startToolbarHeight - finalToolbarHeight;
amountOfImageToReduce = startHeight - finalHeight;
amountToMoveXPosition = startXPositionImage - finalXPosition;
amountToMoveYPosition = startYPositionImage - finalYPosition;
initialised = true;
}
}
}
参考资料
最常见的例子是在 https://github.com/saulmm/CoordinatorBehaviorExample 上列出的那个带狗的例子。这是一个很好的例子,但实际上在扩展视图中有一个位于中间的工具栏和一个移动的背景图像。在我的例子中,所有这些都被删除了。
另一个解释可以在 http://www.devexchanges.info/2016/03/android-tip-custom-coordinatorlayout.html 找到,但由于那里引用的云/海背景图像也在狗例子中找到,因此一个显然是建立在另一个之上的。
我还发现了这个 SO 问题,并获得了悬赏,但无法真正找出最终的解决方案:在 CollapsingToolbarLayout 中添加带标题的图标
最后,这应该是一个可行的库,可以完成工作。我已经检查过了,但最初的图像没有居中,我宁愿使用之前查看过的狗例子。请参见https://github.com/datalink747/CollapsingAvatarToolbar
更多阅读
http://saulmm.github.io/mastering-coordinator http://www.androidauthority.com/using-coordinatorlayout-android-apps-703720/ https://developer.android.com/reference/android/support/design/widget/CoordinatorLayout.html https://guides.codepath.com/android/handling-scrolls-with-coordinatorlayout
layout_behavior
时遇到了问题。如何从不同的包中使用Behavior子类?当我从外部包(utils)中使用它时,它会抛出Class-Not-Found异常。我使用了完整的包名。但是在同一个包中可以工作。您能告诉我如何从不同的包中使用它吗? - ashwin mahajan