Android Material Design - How to change background color of Toolbar after CollapsingToolbarLayout is collapsed

问题

After the user scrolls down the screen, the image in the CollapsingToolbarLayout disappears and is left with a toolbar with the back button, content title, and settings menu. I want to know how to change the background color of that toolbar only when its in a 'collapsed' state.

The action I am referring to is similar to this where the toolbar background color changes to green:

Below the CollapsingToolbarLayout I have a NestedScrollView with CardViews

回答1:

I think you're after app:contentScrim.

<android.support.design.widget.CollapsingToolbarLayout
    ...
    app:contentScrim="?attr/colorPrimary">
    <!-- Toolbar and ImageView here -->
</android.support.design.widget.CollapsingToolbarLayout>

回答2:

First remove

app:contentScrim="?attr/colorPrimary"> 

from CollapsingToolbarLayout

Add library

compile 'com.android.support:palette-v7:23.2.1'

And add below code in java code

    Bitmap bitmap = BitmapFactory.decodeResource(getApplicationContext().getResources(), R.drawable.ny);
    Palette.generateAsync(bitmap,
            new Palette.PaletteAsyncListener() {
                @Override
                public void onGenerated(Palette palette) {
                    Palette.Swatch vibrant =
                            palette.getVibrantSwatch();
                    int mutedColor = palette.getVibrantSwatch().getRgb();
                    if (vibrant != null) {
                        // If we have a vibrant color
                        // update the title TextView
                        collapseToolbar.setBackgroundColor(mutedColor);
                        //  mutedColor = palette.getMutedColor(R.attr.colorPrimary);
                        collapseToolbar.setStatusBarScrimColor(palette.getDarkMutedColor(mutedColor));
                        collapseToolbar.setContentScrimColor(palette.getMutedColor(mutedColor));

                    }
                }
            });

回答3:

Just use CollapsingToolbarLayout XML attribute contentScrim to set Toolbar background color when it's in collapsed mode.

app:contentScrim="YOUR_TOOLBAR_COLOR"

Here is an Example:

<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:layout_scrollFlags="scroll|exitUntilCollapsed">

    <ImageView
        android:id="@+id/img_group_photo"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        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" />
</android.support.design.widget.CollapsingToolbarLayout>

Hope this will help~

回答4:

Maybe what you have been looking for is this :

myCollapsingToolbar.setContentScrimColor(getResources().getColor(R.color.my_color_id));

It worked for me and changed the color of the collapsingToolbar once it was collapsed to help me fit the main color of an image that was displayed when the collapsingToolbar was full scale. With this, the color can obviously be changed programatically!

I know I'm late, but I hope it could help.

回答5:

You can use an AppBarLayout's offset listener and change the CollapsingTollbar attributes according to the desired behavior.

appBarLayout.addOnOffsetChangedListener { _, verticalOffSet ->
            if (Math.abs(verticalOffSet) == appBarLayout.totalScrollRange) {
                //Collapsed
                toolBar.setBackgroundDrawable(ContextCompat.getDrawable(this,
                        R.drawable.last_revolut_gradient))
            } else {
                //Expanded
                toolBar.setBackgroundColor(ContextCompat.getColor(this,
                        android.R.color.transparent))
            }
        }

回答6:

    Bitmap bitmap = BitmapFactory.decodeResource(getResources(),
            R.drawable.header);

    Palette.from(bitmap).generate(new Palette.PaletteAsyncListener() {
        @SuppressWarnings("ResourceType")

        @Override
        public void onGenerated(Palette palette) {
            Palette.Swatch vibrant =
                    palette.getVibrantSwatch();

            if (vibrant != null) {

                collapsingToolbar.setBackgroundColor(getResources().getColor(R.color.cpb_blue));
                collapsingToolbar.setStatusBarScrimColor(getResources().getColor(R.color.cpb_blue));
                collapsingToolbar.setContentScrimColor(getResources().getColor(R.color.cpb_blue));

            }
        }

    });

来源：https://stackoverflow.com/questions/30619598/android-material-design-how-to-change-background-color-of-toolbar-after-collap