android - AppBarLayout fitSystemtWindows =“true"在 layout_height 为 wrap_content 时不起作用

Question

我想构建一个折叠工具栏，并将 View 动态添加到 CollapsingToolBarLayout。所以我需要设置 AppBarLayout wrap_content。

然后我在 android studio 2.2 中创建一个手机和平板电脑模块并选择“滚动 Activity ”。我有一个这样的页面:

然后我将 AppBarLayout 的高度从@dimen/app_bar_height 更改为 wrap_content

<?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"
    xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
    android:layout_height="match_parent" android:fitsSystemWindows="true"
    tools:context="demo.billy.com.test_design.ScrollingActivity">

    <android.support.design.widget.AppBarLayout android:id="@+id/app_bar"
        android:layout_width="match_parent" android:layout_height="wrap_content"
        android:fitsSystemWindows="true" android:theme="@style/AppTheme.AppBarOverlay">

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

            <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/AppTheme.PopupOverlay" />

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

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

    <android.support.design.widget.FloatingActionButton android:id="@+id/fab"
        android:layout_width="wrap_content" android:layout_height="wrap_content"
        android:layout_margin="@dimen/fab_margin" app:layout_anchor="@id/app_bar"
        app:layout_anchorGravity="bottom|end" app:srcCompat="@android:drawable/ic_dialog_email" />
</android.support.design.widget.CoordinatorLayout>

现在页面如下:

ToolBar 被系统状态栏覆盖。看起来 fitSystemWindow="true"不起作用。

我将 AppBarLayout 上的 fitSystemWindow 更改为“false”，如果 CollaspingToolBarLayout 中只有一个子项，它看起来可以工作。但是，当我将 imageView 添加到 CollapsintToolBarLayout 时，状态栏背景不透明。

    <?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"
        xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
        android:layout_height="match_parent" android:fitsSystemWindows="true"
        tools:context="demo.billy.com.test_design.ScrollingActivity">

        <android.support.design.widget.AppBarLayout android:id="@+id/app_bar"
            android:layout_width="match_parent" android:layout_height="wrap_content"
            android:fitsSystemWindows="false" android:theme="@style/AppTheme.AppBarOverlay">

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

                <ImageView
                    android:id="@+id/image_collapsing"
                    android:layout_width="match_parent"
                    android:layout_height="match_parent"
                    android:fitsSystemWindows="true"
                    app:layout_collapseMode="parallax"
                    app:layout_collapseParallaxMultiplier="0.5"
                    android:scaleType="centerCrop"
                    android:src="@drawable/img"
                    />
                <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/AppTheme.PopupOverlay" />

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

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

        <android.support.design.widget.FloatingActionButton android:id="@+id/fab"
            android:layout_width="wrap_content" android:layout_height="wrap_content"
            android:layout_margin="@dimen/fab_margin" app:layout_anchor="@id/app_bar"
            app:layout_anchorGravity="bottom|end" app:srcCompat="@android:drawable/ic_dialog_email" />

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

我需要做的是:

1. ToolBar 不能被系统状态栏覆盖
2. CollapsingToolbarLayout 可能只有一个 child :ToolBar
3. CollapsingToolbarLayout 可能有很多 child :ToolBar + ImageView + 等...

有人帮我吗？

Answer 1

我自己的解决方案:

覆盖 CollapsingToolbarLayout.onMeasure()，如有必要，将 status_bar_height 添加到布局高度:

public class MyCollapsingToolbarLayout extends CollapsingToolbarLayout {

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

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

    public MyCollapsingToolbarLayout(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        Toolbar toolbar = null;
        int otherHeight = 0;
        //calculate max visible toolbar height
        for (int i = 0; i < getChildCount(); i++) {
            View view = getChildAt(i);
            if (view instanceof Toolbar) {
                toolbar = (Toolbar) view;
            } else if(view.getVisibility() != GONE) {
                otherHeight = Math.max(otherHeight, view.getHeight());
            }
        }
        if (toolbar != null) {
            int sizeWidth = MeasureSpec.getSize(widthMeasureSpec);
            int sizeHeight = MeasureSpec.getSize(heightMeasureSpec);
            int modeWidth = MeasureSpec.getMode(widthMeasureSpec);
            int modeHeight = MeasureSpec.getMode(heightMeasureSpec);
            final int paddingWidth = getPaddingLeft() + getPaddingRight();
            final int paddingHeight = getPaddingTop() + getPaddingBottom();
            int height = paddingHeight;
            LayoutParams lp = (LayoutParams) toolbar.getLayoutParams();
            final int marginWidth = lp.rightMargin + lp.leftMargin;
            final int marginHeight = lp.topMargin + lp.bottomMargin;
            toolbar.measure(
                    getChildMeasureSpec(widthMeasureSpec, paddingWidth + marginWidth, lp.width),
                    getChildMeasureSpec(heightMeasureSpec, paddingHeight + marginHeight, lp.height)
            );
            int toolbarHeight = toolbar.getMeasuredHeight() + marginHeight;
            height += toolbarHeight;
            height += getStatusBarHeight();
            if (height > otherHeight) {
                setMeasuredDimension((modeWidth == MeasureSpec.EXACTLY) ? sizeWidth : getWidth()
                        , (modeHeight == MeasureSpec.EXACTLY) ? sizeHeight : height);

            }
        }
    }
    private int getStatusBarHeight() {
        Resources res = Resources.getSystem();
        int resId = res.getIdentifier("status_bar_height", "dimen", "android");
        if (resId > 0) {
            return res.getDimensionPixelSize(resId);
        }
        return 0;
    }

}