android - 需要为某些片段禁用 CollapsingToolbarLayout 上的展开

Question

我有一个 AppCompatActivity 控制替换许多片段。这是我的布局。

activity_main.xml

<android.support.v4.widget.DrawerLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="@+id/drawer_layout"
android:layout_height="match_parent"
android:layout_width="match_parent"
android:fitsSystemWindows="true">

<include layout="@layout/activity_main_frame"/>

<android.support.design.widget.NavigationView
    android:id="@+id/navigation_view"
    android:layout_width="wrap_content"
    android:layout_height="match_parent"
    android:layout_gravity="start"
    android:fitsSystemWindows="true"
    android:background="@color/white"
    app:headerLayout="@layout/drawer_header"
    app:menu="@menu/drawer"/>

</android.support.v4.widget.DrawerLayout>

activity_main_frame.xml

<android.support.design.widget.CoordinatorLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/main_content"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fitsSystemWindows="true">

    <android.support.design.widget.AppBarLayout
        android:id="@+id/appbar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
        android:fitsSystemWindows="true">

        <android.support.design.widget.CollapsingToolbarLayout
            android:id="@+id/collapsing_toolbar"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            app:layout_scrollFlags="scroll|exitUntilCollapsed"
            android:fitsSystemWindows="true"
            app:contentScrim="?attr/colorPrimary"
            app:expandedTitleMarginStart="48dp"
            app:expandedTitleMarginEnd="64dp">

            <ImageView
                android:id="@+id/backdrop"
                android:layout_width="match_parent"
                android:layout_height="256dp"
                android:scaleType="centerCrop"
                android:fitsSystemWindows="true"
                app:layout_collapseMode="parallax" />

            <include layout="@layout/activity_main_items"/>

            <android.support.v7.widget.Toolbar
                android:id="@+id/toolbar"
                android:layout_width="match_parent"
                android:layout_height="?attr/actionBarSize"
                app:popupTheme="@style/ThemeOverlay.AppCompat.Light"
                app:layout_collapseMode="pin"/>

            <android.support.design.widget.TabLayout
                android:id="@+id/tabs"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:visibility="gone"
                android:layout_gravity="bottom"/>

        </android.support.design.widget.CollapsingToolbarLayout>

    </android.support.design.widget.AppBarLayout>

    <FrameLayout
        android:id="@+id/content_frame"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:layout_behavior="@string/appbar_scrolling_view_behavior" >
    </FrameLayout>

    <android.support.design.widget.FloatingActionButton
        android:id="@+id/fab1"
        android:layout_height="wrap_content"
        android:layout_width="wrap_content"
        app:layout_anchor="@id/appbar"
        app:layout_anchorGravity="bottom|right|end"
        app:borderWidth="0dp"
        android:src="@drawable/app_ic_slide_wallpaper_dark"
        android:layout_margin="@dimen/big_padding"
        android:clickable="true"/>

</android.support.design.widget.CoordinatorLayout>

我的主页片段最初是设置的，这就是我希望折叠工具栏展开的地方，并且工作正常。但是，当我从侧抽屉更改片段时，我想禁用扩展工具栏。

我已经知道如何在选择抽屉项目时折叠它，但我还需要确保它不会展开，除非显示主片段。这可能吗？

public void collapseToolbar(){
        CoordinatorLayout.LayoutParams params = (CoordinatorLayout.LayoutParams) appbar.getLayoutParams();
        behavior = (AppBarLayout.Behavior) params.getBehavior();
        if(behavior!=null) {
            behavior.onNestedFling(coordinator, appbar, null, 0, 10000, true);
        }
    }

score 67 · Accepted Answer

禁用滚动片段内容的嵌套滚动：

recyclerView.setNestedScrollingEnabled(false);

如果您使用的是支持库，请使用它：

ViewCompat.setNestedScrollingEnabled(recyclerView, false);

score 37 · Accepted Answer

此类将允许您禁用/重新启用扩展行为。

public class DisableableAppBarLayoutBehavior extends AppBarLayout.Behavior {
    private boolean mEnabled;

    public DisableableAppBarLayoutBehavior() {
        super();
    }

    public DisableableAppBarLayoutBehavior(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public void setEnabled(boolean enabled) {
        mEnabled = enabled;
    }

    @Override
    public boolean onStartNestedScroll(CoordinatorLayout parent, AppBarLayout child, View directTargetChild, View target, int nestedScrollAxes) {
        return mEnabled && super.onStartNestedScroll(parent, child, directTargetChild, target, nestedScrollAxes);
    }

    public boolean isEnabled() {
        return mEnabled;
    }
}

在您的布局中使用它，如下所示：

<android.support.design.widget.AppBarLayout
    ... other attributes ...
    app:layout_behavior="com.yourpackage.DisableableAppBarLayoutBehavior"
    >
    <!-- your app bar contents -->
</android.support.design.widget.AppBarLayout>

然后，当您要禁用该行为时：

AppBarLayout myAppBar = ....;
CoordinatorLayout.LayoutParams layoutParams = (CoordinatorLayout.LayoutParams) myAppBar.getLayoutParams();
((DisableableAppBarLayoutBehavior) layoutParams.getBehavior()).setEnabled(false);

score 20 · Accepted Answer

现在，在 v23 的支持库中，您可以轻松控制应用栏的可见性。

只需获取对您的 AppBarLayout 的引用并根据您要加载的片段隐藏/显示它：

private AppBarLayout appBarLayout;

@Override
protected void onCreate(Bundle savedInstanceState) {
[...]
appBarLayout = (AppBarLayout) findViewById(R.id.appbar);
[...]
}

public void switchToFragment(Fragment fragment, String tag, boolean expandToolbar){
        FragmentManager fragmentManager = getSupportFragmentManager();

        Fragment currentFragment = fragmentManager.findFragmentByTag(currentFragmentTag);

        if(currentFragment == null || !TextUtils.equals(tag, currentFragmentTag) ){
            currentFragmentTag = tag;
            fragmentManager
                    .beginTransaction()
                    .replace(R.id.flContent, fragment, currentFragmentTag)
                    .commit();

            if(expandToolbar){
                appBarLayout.setExpanded(true,true);
            }else{
                appBarLayout.setExpanded(false,true);
            }
        }
    }

PS 不要忘记在 build.gradle 中添加所需的依赖项：

dependencies {  
    compile 'com.android.support:design:23.2.1'
    compile 'com.android.support:appcompat-v7:23.2.1'
    compile 'com.android.support:recyclerview-v7:23.2.1' 
}

编辑： 如果您还想将工具栏锁定在某些片段中（除了折叠），您必须求助于解决方法，因为 CollapsingToolbarLayout 直到现在（支持设计的 v23.2.1）才提供此功能。在这里您可以找到我提出的解决方法。

score 11 · Accepted Answer

您所要做的就是用 CoordinatorLayout 的自定义实现替换 CoordinatorLayout，这将欺骗嵌套滚动已被处理。

MyCoordinatorLayout 实现：

public class MyCoordinatorLayout extends CoordinatorLayout {

    private boolean allowForScroll = false;

    public MyCoordinatorLayout(Context context) {
        super(context);
    }

    public MyCoordinatorLayout(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    @Override public boolean onStartNestedScroll(View child, View target, int nestedScrollAxes) {
        return allowForScroll && super.onStartNestedScroll(child, target, nestedScrollAxes);
    }

    public boolean isAllowForScroll() {
        return allowForScroll;
    }

    public void setAllowForScroll(boolean allowForScroll) {
        this.allowForScroll = allowForScroll;
    }
}

活动视图xml：

<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    >

    <android.support.v4.widget.DrawerLayout
        android:id="@+id/drawerLayout"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        >

        <!--CONTENT-->

        <com.example.views.MyCoordinatorLayout
            android:id="@+id/coordinator"
            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:fitsSystemWindows="true"
            >

        <com.example.views.ControllableAppBarLayout
            android:id="@+id/appbar"
            android:layout_width="match_parent"
            android:layout_height="192dp"
            android:fitsSystemWindows="true"
            android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">

            <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="@color/primary"
                    android:fitsSystemWindows="true"
                    android:scaleType="centerCrop"
                    app:layout_collapseMode="parallax" />

                <android.support.v7.widget.Toolbar
                    android:id="@+id/toolbar"
                    android:layout_width="match_parent"
                    android:layout_height="?attr/actionBarSize"
                    app:layout_collapseMode="pin"
                    app:popupTheme="@style/ThemeOverlay.AppCompat.Light" />

            </android.support.design.widget.CollapsingToolbarLayout>

        </com.example.views.ControllableAppBarLayout>

        <FrameLayout
            android:id="@+id/flContent"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            app:layout_behavior="@string/appbar_scrolling_view_behavior"
            />

        </com.example.views.MyCoordinatorLayout>


        <!-- DRAWER -->

        <fragment
            android:id="@+id/fDrawer"
            android:name="com.example.fragment.DrawerFragment"
            android:layout_width="@dimen/drawer_width"
            android:layout_height="match_parent"
            android:layout_gravity="left|start"
            android:fitsSystemWindows="true"
            android:clickable="true"
            />

    </android.support.v4.widget.DrawerLayout>

</LinearLayout>

我鼓励您使用自定义 AppBarLayout 实现和辅助方法来折叠/展开工具栏。在这个要点上，你可以找到一个。

好的，现在是时候在活动中配置我们的工具栏了。

public class ToolbarAppcompatActivity extends AppCompatActivity
        implements AppBarLayout.OnOffsetChangedListener {

    protected Toolbar toolbar;
    protected MyCoordinatorLayout coordinator;
    protected ControllableAppBarLayout appbar;

    @Override protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        configureToolbar();
    switchFragment(new FooFragment(), "FOO", true);
    }

    protected void configureToolbar() {
        toolbar = (Toolbar) findViewById(R.id.toolbar);
        coordinator = (MyCoordinatorLayout) findViewById(R.id.coordinator);
        appbar = (ControllableAppBarLayout) findViewById(R.id.appbar);
        appbar.addOnOffsetChangedListener(this);
        getDelegate().setSupportActionBar(toolbar);
    }

    public void switchToFragment(Fragment fragment, String tag, boolean expandToolbar){
        FragmentManager fragmentManager = getSupportFragmentManager();

        Fragment currentFragment = fragmentManager.findFragmentByTag(currentFragmentTag);

        if(currentFragment == null || !TextUtils.equals(tag, currentFragmentTag) ){
            currentFragmentTag = tag;
            fragmentManager
                    .beginTransaction()
                    .replace(R.id.flContent, fragment, currentFragmentTag)
                    .commit();

            if(expandToolbar){
                expandToolbar();
            }else{
                collapseToolbar();
            }
        }
    }

    protected void addFragment(Fragment fragment, String tag, boolean expandToolbar) {
        FragmentManager fragmentManager = getSupportFragmentManager();
        currentFragmentTag = tag;
        fragmentManager
                .beginTransaction()
                .add(R.id.flContent, fragment, currentFragmentTag)
                .addToBackStack(tag)
                .commit();

        if(expandToolbar){
            expandToolbar();
        }else{
            collapseToolbar();
        }
    }

   protected void collapseToolbar(){
        appbar.collapseToolbar();
        coordinator.setAllowForScroll(false);
    }

    public void expandToolbar(){
        appbar.expandToolbar();
        coordinator.setAllowForScroll(true);
    }

}

每次您想要切换片段和折叠/展开工具栏时，只需使用适当的布尔参数调用方法 switchFragment/addFragment。

只是最后一点。确保您使用最新的支持库。

dependencies {

    // android support
    compile 'com.android.support:appcompat-v7:22.2.1'
    compile 'com.android.support:recyclerview-v7:22.2.1'
    compile 'com.android.support:design:22.2.1'

}

不要在 AppBarLayout 中使用 include 标签。这没用

score 7 · Accepted Answer

以下代码实现了 3 个目标：

禁用 CollapsingToolbarLayout 由用户展开或折叠，但仍允许AppBarLayout.setExpanded.

防止 RecyclerView 或 NestedScrollView 的滚动展开或折叠 CollapsingToolbarLayout。

// scrollView can be RecyclerView or NestedScrollView
ViewCompat.setNestedScrollingEnabled(scrollView, false)

防止用户通过轻弹 AppBar 来展开或折叠 CollapsingToolbarLayout。

val params = appBar.layoutParams as CoordinatorLayout.LayoutParams
if (params.behavior == null)
    params.behavior = AppBarLayout.Behavior()
val behaviour = params.behavior as AppBarLayout.Behavior
behaviour.setDragCallback(object : AppBarLayout.Behavior.DragCallback() {
    override fun canDrag(appBarLayout: AppBarLayout): Boolean {
        return false
    }
})

https://code.luasoftware.com/tutorials/android/how-to-disable-or-lock-collapsingtoolbarlayout-collapse-or-expand/

score 5 · Accepted Answer

对于 Android Design Library v23.1.1，@LucyFair 描述的方法不起作用。我设法通过将其设置app:layout_scrollFlags为enterAlwaysCollapsedonly 来使其工作，并且 appbar 保持“锁定”状态。

希望这可以帮助。:)

score 5 · Accepted Answer

我使用了@JasonWyatt的解决方案并添加DragCallback到行为类中以防止触摸和拖动CollapsingToolbarLayout以扩展它

private void setDragCallback() {
    setDragCallback(new DragCallback() {
        @Override
        public boolean canDrag(@NonNull AppBarLayout appBarLayout) {
            return mEnabled;
        }
    });
}

score 4 · Accepted Answer

我找到了一种适用于活动和各种片段的解决方案。您在活动中使用 AppBar 等实现 CollapsingToolbarLayout，然后每次调用新片段时都可以调用这两个函数。

当我希望我的应用栏保持折叠状态时：

public void lockAppBarClosed() {
    mAppBarLayout.setExpanded(false, false);
    mAppBarLayout.setActivated(false);
    CoordinatorLayout.LayoutParams lp = (CoordinatorLayout.LayoutParams)mAppBarLayout.getLayoutParams();
    lp.height = (int) getResources().getDimension(R.dimen.toolbar_height);
}

当我希望我的应用栏再次扩展和可滚动时

public void unlockAppBarOpen() {
    mAppBarLayout.setExpanded(true, false);
    mAppBarLayout.setActivated(true);
    CoordinatorLayout.LayoutParams lp = (CoordinatorLayout.LayoutParams)mAppBarLayout.getLayoutParams();
    lp.height = (int) getResources().getDimension(R.dimen.toolbar_expand_height);
}

您可以通过实现接口从片段中调用这些函数。这是一个简单的示例，适用于您的情况（工具栏仅在 homeFragment 中扩展）

public interface CustomListener() {
    void unlockAppBarOpen();
    void lockAppBarClosed()
}

public class MainActivity extends BaseActivity implements CustomListener {

    @Override
    public void unlockAppBarOpen() {
        mAppBarLayout.setExpanded(true, false);
        mAppBarLayout.setActivated(true);
        CoordinatorLayout.LayoutParams lp = (CoordinatorLayout.LayoutParams)mAppBarLayout.getLayoutParams();
        lp.height = (int) getResources().getDimension(R.dimen.toolbar_expand_height);
    }

    @Override
    public void lockAppBarClosed() {
        mAppBarLayout.setExpanded(false, false);
        mAppBarLayout.setActivated(false);
        CoordinatorLayout.LayoutParams lp = (CoordinatorLayout.LayoutParams)mAppBarLayout.getLayoutParams();
        lp.height = (int) getResources().getDimension(R.dimen.toolbar_height);
    }
}

public class MainFragment extends BaseFragment {

    @Override
    public void onResume() {
        super.onPause();
        ((MainActivity) getContext()).unlockAppBarOpen();
    }
}

public class SecondFragment extends BaseFragment {

    @Override
    public void onResume() {
        super.onPause();
        ((MainActivity) getContext()).lockAppBarClosed();
    }
}

用这个例子：

每次将显示 MainFragment -> 它将扩展工具栏并使其可折叠和可展开
每次显示 SecondFragment -> il 都会将工具栏折叠到标准大小并防止它再次展开

希望它会帮助你！

score 4 · Accepted Answer

我在 CollapsingToolbarLayout 中找到了启用/禁用折叠的简单解决方案：

    private void setExpandEnabled(boolean enabled) {
        mAppBarLayout.setExpanded(enabled, false);
        mAppBarLayout.setActivated(enabled);
        final AppBarLayout.LayoutParams params = (AppBarLayout.LayoutParams) collapsingToolbarLayout.getLayoutParams();
        if (enabled)
            params.setScrollFlags(AppBarLayout.LayoutParams.SCROLL_FLAG_SCROLL | AppBarLayout.LayoutParams.SCROLL_FLAG_EXIT_UNTIL_COLLAPSED);
        else
            params.setScrollFlags(AppBarLayout.LayoutParams.SCROLL_FLAG_ENTER_ALWAYS | AppBarLayout.LayoutParams.SCROLL_FLAG_EXIT_UNTIL_COLLAPSED);
        collapsingToolbarLayout.setLayoutParams(params);
    }

score 4 · Accepted Answer

我无法发表评论，因此我会将我对JasonWyatt 的DisableAppBarLayoutBehavior 解决方案的补充作为独立答案发布。

public class DisableableAppBarLayoutBehavior extends AppBarLayout.Behavior {
    private boolean mEnabled = true; // enabled by default

    public DisableableAppBarLayoutBehavior() {
        super();
    }

    public DisableableAppBarLayoutBehavior(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public void setEnabled(boolean enabled) {
        mEnabled = enabled;
    }

    @Override
    public boolean onStartNestedScroll(CoordinatorLayout parent, AppBarLayout child, View directTargetChild, View target, int nestedScrollAxes, int type) {
        return mEnabled && super.onStartNestedScroll(parent, child, directTargetChild, target, nestedScrollAxes, type);
    }

    @Override
    public void onNestedScroll(CoordinatorLayout coordinatorLayout, AppBarLayout child, View target, int dxConsumed, int dyConsumed, int dxUnconsumed, int dyUnconsumed, int type) {
        if (!isEnabled()) return;
        super.onNestedScroll(coordinatorLayout, child, target, dxConsumed, dyConsumed, dxUnconsumed, dyUnconsumed, type);
    }

    @Override
    public void onNestedPreScroll(CoordinatorLayout coordinatorLayout, AppBarLayout child, View target, int dx, int dy, int[] consumed, int type) {
        if (!isEnabled()) return;
        super.onNestedPreScroll(coordinatorLayout, child, target, dx, dy, consumed, type);
    }

    public boolean isEnabled() {
        return mEnabled;
    }
}

除了 onStartNestedScroll 还锁定onNestedPreScroll和onNestedScroll本身以避免意外行为。例如，在我的情况下 - 在我的应用栏上调用setExpanded(false, true)会阻碍预期的行为，并且仍然会延迟扩展。现在它起作用了：

LayoutParams layoutParams = (LayoutParams) context.appBarLayout.getLayoutParams();
((DisableableAppBarLayoutBehavior)layoutParams.getBehavior()).setEnabled(false);
context.appBarLayout.setLayoutParams(layoutParams);
context.appBarLayout.setExpanded(false, true); // collapse app bar

score 1 · Accepted Answer

除了这个之外，提供的解决方案都不适合我。使用此解决方案，我可以轻松管理折叠工具栏的状态。这将防止折叠工具栏的展开并为其设置标题。

public void lockAppBar(boolean locked,String title) {
    if(locked){
        appBarLayout.setExpanded(false, true);
        int px = (int)TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 80, getResources().getDisplayMetrics());
        CoordinatorLayout.LayoutParams lp = (CoordinatorLayout.LayoutParams)appBarLayout.getLayoutParams();
        lp.height = px;
        appBarLayout.setLayoutParams(lp);
        collapsingToolbarLayout.setTitleEnabled(false);
        toolbar.setTitle(title);
    }else{
        appBarLayout.setExpanded(true, false);
        appBarLayout.setActivated(true);
        CoordinatorLayout.LayoutParams lp = (CoordinatorLayout.LayoutParams) appBarLayout.getLayoutParams();
        lp.height = (int) getResources().getDimension(R.dimen.toolbarExpandHeight);
        collapsingToolbarLayout.setTitleEnabled(true);
        collapsingToolbarLayout.setTitle(title);
    }
}

score 1 · Accepted Answer

像这样找到 AppBarLayout id。

appBarLayout = (AppBarLayout) findViewById(R.id.appbar);

对某些片段禁用 CollapsingToolbarLayout 的展开

appBarLayout.setExpanded(true,true);

为某些片段启用 CollapsingToolbarLayout 的展开

appBarLayout.setExpanded(false,true);

希望对你有帮助！！

score 1 · Accepted Answer

锁定和解锁是不够的，简单的锁定会使图像缩小；这是我的解决方案

在需要工具栏处于折叠模式的恢复时调用它。


private void lockAppBarClosed() {

    appBarLayout.setExpanded(false,true);
    CoordinatorLayout.LayoutParams layoutParams = (CoordinatorLayout.LayoutParams) appBarLayout.getLayoutParams();
    ((CustomAppBarLayoutBehavior)layoutParams.getBehavior()).setScrollBehavior(false);

    AppBarLayout.LayoutParams params = (AppBarLayout.LayoutParams) collapsingToolbarLayout.getLayoutParams();
    params.setScrollFlags(0);
    params.setScrollFlags(AppBarLayout.LayoutParams.SCROLL_FLAG_SCROLL | AppBarLayout.LayoutParams.SCROLL_FLAG_EXIT_UNTIL_COLLAPSED);

}

这是针对需要的片段Snap

public void unlockAppBarOpen() {

    appBarLayout.setExpanded(true,true);
    CoordinatorLayout.LayoutParams layoutParams = (CoordinatorLayout.LayoutParams) appBarLayout.getLayoutParams();
    ((CustomAppBarLayoutBehavior)layoutParams.getBehavior()).setScrollBehavior(true);


    AppBarLayout.LayoutParams params = (AppBarLayout.LayoutParams) collapsingToolbarLayout.getLayoutParams();
    params.setScrollFlags(0);
    params.setScrollFlags(AppBarLayout.LayoutParams.SCROLL_FLAG_SCROLL | AppBarLayout.LayoutParams.SCROLL_FLAG_SNAP);

}

这是针对需要滚动SCROLL_FLAG_EXIT_UNTIL_COLLAPSED模式的片段。


public void unlockAppBarOpen() {

    appBarLayout.setExpanded(true,true);
    CoordinatorLayout.LayoutParams layoutParams = (CoordinatorLayout.LayoutParams) appBarLayout.getLayoutParams();
    ((CustomAppBarLayoutBehavior)layoutParams.getBehavior()).setScrollBehavior(true);


    AppBarLayout.LayoutParams params = (AppBarLayout.LayoutParams) collapsingToolbarLayout.getLayoutParams();
    params.setScrollFlags(0);
    params.setScrollFlags(AppBarLayout.LayoutParams.SCROLL_FLAG_SCROLL | AppBarLayout.LayoutParams.SCROLL_FLAG_EXIT_UNTIL_COLLAPSED);

}

和 CustomAppBarLayoutBehavior.java

public class CustomAppBarLayoutBehavior extends AppBarLayout.Behavior {

    private boolean shouldScroll = false;

    public CustomAppBarLayoutBehavior() {
        super();
    }

    public CustomAppBarLayoutBehavior(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    @Override
    public boolean onStartNestedScroll(CoordinatorLayout parent, AppBarLayout child, View directTargetChild, View target, int nestedScrollAxes, int type) {
        return shouldScroll;
    }

    @Override
    public boolean onTouchEvent(CoordinatorLayout parent, AppBarLayout child, MotionEvent ev) {
        if(shouldScroll){
            return super.onTouchEvent(parent, child, ev);
        }else{
            return false;
        }
    }

    public void setScrollBehavior(boolean shouldScroll){
        this.shouldScroll = shouldScroll;
    }

    public boolean isShouldScroll(){
        return shouldScroll;
    }
}

将此行为提供给 AppBarLayout

 <com.google.android.material.appbar.AppBarLayout
        android:id="@+id/app_bar_layout"
        android:layout_width="match_parent"
        android:layout_height="210dp"
        app:layout_behavior=".behaviors.CustomAppBarLayoutBehavior"
        android:theme="@style/ThemeOverlay.MaterialComponents.ActionBar.Primary">

score 0 · Accepted Answer

您可以通过将折叠工具栏高度重置为工具栏高度来锁定 appbarlayout 扩展

toolbarHeight = toolbar.getLayoutParams().height;

if (expand) {
    collapsingToolbar.getLayoutParams().height = getResources().getDimensionPixelOffset(R.dimen.collapsingToolbarDefaultHeight);
    appBarLayout.setExpanded(true, true);
} else {
    //collapse
    //** it is important you do this before resetting **
    appBarLayout.setExpanded(false, true);
    appBarLayout.postDelayed(new Runnable() {
        @Override
        public void run() {
            collapsingToolbar.getLayoutParams().height = toolbarHeight;
        }
     }, 700/* 600 is default animation time to collapse */);
}

score 0 · Accepted Answer

感谢@Desmond Lua 的出色回答，我终于能够在我的代码中解决这个问题。这是我使用 Java 和数据绑定的改编解决方案。

<com.google.android.material.appbar.AppBarLayout
    android:id="@+id/app_bar"
    bind:expanded="@{myCondition? false : true}"
    app:disableCollapsingScroll="@{myCondition? false : true}"
    ... >

        <com.google.android.material.appbar.CollapsingToolbarLayout
            ... >

            ...

        </com.google.android.material.appbar.CollapsingToolbarLayout>
    </com.google.android.material.appbar.AppBarLayout>

<androidx.core.widget.NestedScrollView 
   android:nestedScrollingEnabled="@{myCondition? false : true}"
   ... >

   ...

</NestedScrollView>

@BindingAdapter("disableCollapsingScroll")
public static void bindDisableCollapsingScroll(AppBarLayout appBarLayout, boolean disabled) {
    CoordinatorLayout.LayoutParams params = (CoordinatorLayout.LayoutParams) appBarLayout.getLayoutParams();

    if (params.getBehavior() == null) {
        params.setBehavior(new AppBarLayout.Behavior());
    }

    AppBarLayout.Behavior behavior = (AppBarLayout.Behavior) params.getBehavior();
    behavior.setDragCallback(new AppBarLayout.Behavior.DragCallback() {
        @Override
        public boolean canDrag(@NonNull AppBarLayout appBarLayout) {
            return disabled;
        }
    });
}

android - 需要为某些片段禁用 CollapsingToolbarLayout 上的展开

15 回答 15

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