使用appcompat时设置RecyclerView边缘发光前棒棒糖

Question

我正在寻找一种方法来在使用appcompat材质主题时在RecyclerView pre-lollip中设置过度滚动指示器的颜色。

在内部，它使用EdgeEffect设置为内部可设置属性，除非你已经在棒棒糖（具有讽刺意味），否则无法设置。

使用反射不起作用，只能在棒棒糖上设置EdgeEffect的颜色。

在我的API21应用程序上，它从主要材料颜色中提取，在Kitkat上它是白色的，之前它是全蓝色的，我想要统一我的设计。

关于它是如何完成的任何想法？

Answer 1

使用以下设置边缘效果发光颜色。适用于支持EdgeEffect（API 14+）的所有平台版本，否则将无声地失败。

void themeRecyclerView(Context context, RecyclerView recyclerView) {
    int yourColor = Color.parseColor("#your_color");
    try {
        final Class<?> clazz = RecyclerView.class;
        for (final String name : new String[]{"ensureTopGlow", "ensureBottomGlow", "ensureLeftGlow", "ensureRightGlow"}) {
            Method method = clazz.getDeclaredMethod(name);
            method.setAccessible(true);
            method.invoke(recyclerView);
        }
        for (final String name : new String[]{"mTopGlow", "mBottomGlow", "mRightGlow", "mLeftGlow"}) {
            final Field field = clazz.getDeclaredField(name);
            field.setAccessible(true);
            final Object edge = field.get(recyclerView);
            final Field fEdgeEffect = edge.getClass().getDeclaredField("mEdgeEffect");
            fEdgeEffect.setAccessible(true);
            setEdgeEffectColor((EdgeEffect) fEdgeEffect.get(edge), yourColor);
        }
    } catch (final Exception | NoClassDefFoundError ignored) {
    }
}

void setEdgeEffectColor(EdgeEffect edgeEffect, int color) {
    try {
        if (Build.VERSION.SDK_INT >= 21) {
            edgeEffect.setColor(color);
            return;
        }

        for(String name : new String[]{"mEdge", "mGlow"}){
            final Field field = EdgeEffect.class.getDeclaredField(name);
            field.setAccessible(true);
            final Drawable drawable = (Drawable) field.get(edgeEffect);
            drawable.setColorFilter(color, PorterDuff.Mode.SRC_IN);
            drawable.setCallback(null);
        }
    } catch (final Exception | NoClassDefFoundError ignored) {
    }
}

感谢@Lukas Novak提供了大部分代码..

正如Lukas所说，必须在onScrollListener的{​​{1}}内调用这些方法：

RecyclerView

Answer 2

感谢@TomášLinhart指出它。以下解决方案仅用于在API＆gt; 21中改变边缘颜色。它可以与AppCompat一起使用，但只有在棒棒糖及以上才能看到改变颜色的效果。

---

我找到了一种使用反射来设置颜色的方法。例如，这里是更改顶部和底部边缘颜色的代码：

public static void setEdgeGlowColor(final RecyclerView recyclerView, final int color) {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
        try {
            final Class<?> clazz = RecyclerView.class;
            for (final String name : new String[] {"ensureTopGlow", "ensureBottomGlow"}) {
                Method method = clazz.getDeclaredMethod(name);
                method.setAccessible(true);
                method.invoke(recyclerView);
            }
            for (final String name : new String[] {"mTopGlow", "mBottomGlow"}) {
                final Field field = clazz.getDeclaredField(name);
                field.setAccessible(true);
                final Object edge = field.get(recyclerView); // android.support.v4.widget.EdgeEffectCompat
                final Field fEdgeEffect = edge.getClass().getDeclaredField("mEdgeEffect");
                fEdgeEffect.setAccessible(true);
                ((EdgeEffect) fEdgeEffect.get(edge)).setColor(color);
            }
        } catch (final Exception ignored) {}
    }
}

与其他组件（如ListView或ScrollView）的解决方案不同，此处必须调用包私有方法ensureTopGlow，ensureBottomGlow等，并在setEdgeEffectColor(RecyclerView recycler, int color)方法中调用上面的onScrollStateChanged RecyclerView.OnScrollListener。

例如：

recyclerView.setOnScrollListener(new RecyclerView.OnScrollListener() {
      @Override
      public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
           super.onScrollStateChanged(recyclerView, newState);
           EdgeChanger.setEdgeGlowColor(recycler, getResources().getColor(R.color.your_color));
      }
});

默认情况下，Android会在开始滚动时调用ensure*Glow方法。在这些方法中，初始化的新EdgeEffect具有默认颜色，但仅在尚未初始化时。要防止出现这种情况，您必须调用ensure*Glow方法，然后更改边缘的颜色，以便后续初始化EdgeEffect将被忽略（如上面的setEdgeGlowColor方法）

Answer 3

EdgeEffect正在使用drawable，因此您可以更改this article中描述的drawable，但它会影响您上下文中的所有EdgeEffect类。

基本上只是介绍和调用这种方法，但是文章中描述了一些陷阱，所以我建议你先阅读它。

static void brandGlowEffect(Context context, int brandColor) {
      //glow
      int glowDrawableId = context.getResources().getIdentifier("overscroll_glow", "drawable", "android");
      Drawable androidGlow = context.getResources().getDrawable(glowDrawableId);
      androidGlow.setColorFilter(brandColor, PorterDuff.Mode.SRC_IN);
      //edge
      int edgeDrawableId = context.getResources().getIdentifier("overscroll_edge", "drawable", "android");
      Drawable androidEdge = context.getResources().getDrawable(edgeDrawableId);
      androidEdge.setColorFilter(brandColor, PorterDuff.Mode.SRC_IN);
}

Answer 4

我一直无法找到为RecyclerViews设置过度滚动颜色的方法。

因此，可能的解决方案是为v21之前和之后的版本设置不同的布局文件。

• Pre-v21：使用listviews并通过https://github.com/AndroidAlliance/EdgeEffectOverride
设置过卷颜色
• post-v21：使用recyclerviews并通过colorAccent
设置过度滚动颜色

缺点是你的代码会很乱，你需要为recyclerview / listview提供两个不同的适配器。

Answer 5

我写了实用程序类EdgeChanger，它是我之前发布的帖子@Jared Hummler code和@Eugen Pechanec code的混合。

此实用程序类使用反射来改变边缘发光的颜色

ScrollView, NestedScrollView, ListView, ViewPager and RecyclerView

在使用AppCompat时与Marshmallow，Lollipop和pre-Lollipop设备配合使用，因此您无需使用EdgeEffectOverride等第三方库或使用不同的布局。

仅在想要在onCreate（）之后更改边缘发光颜色时使用此选项，否则应使用setTheme和不同主题使用不同颜色属性colorPrimary或​​colorEdgeEffect。

public class EdgeChanger {

private static final Class<?> CLASS_SCROLL_VIEW = ScrollView.class;
private static Field SCROLL_VIEW_FIELD_EDGE_GLOW_TOP;
private static Field SCROLL_VIEW_FIELD_EDGE_GLOW_BOTTOM;

private static final Class<?> CLASS_LIST_VIEW = AbsListView.class;
private static Field LIST_VIEW_FIELD_EDGE_GLOW_TOP;
private static Field LIST_VIEW_FIELD_EDGE_GLOW_BOTTOM;

private static final Class<?> CLASS_NESTED_SCROLL_VIEW = NestedScrollView.class;
private static Field NESTED_SCROLL_VIEW_FIELD_EDGE_GLOW_TOP;
private static Field NESTED_SCROLL_VIEW_FIELD_EDGE_GLOW_BOTTOM;
private static Method NESTED_SCROLL_VIEW_METHOD_ENSURE_GLOWS;

private static final Class<?> CLASS_RECYCLER_VIEW = RecyclerView.class;
private static Field RECYCLER_VIEW_FIELD_EDGE_GLOW_TOP;
private static Field RECYCLER_VIEW_FIELD_EDGE_GLOW_BOTTOM;
private static Method RECYCLER_VIEW_METHOD_ENSURE_GLOW_TOP;
private static Method RECYCLER_VIEW_METHOD_ENSURE_GLOW_BOTTOM;

private static final Class<?> CLASS_VIEW_PAGER = ViewPager.class;
private static Field VIEW_PAGER_FIELD_EDGE_GLOW_LEFT;
private static Field VIEW_PAGER_FIELD_EDGE_GLOW_RIGHT;

static {

    Field edgeGlowTop = null, edgeGlowBottom = null;
    Method ensureGlowTop = null, ensureGlowBottom = null;

    for (Field f : CLASS_SCROLL_VIEW.getDeclaredFields()) {
        switch (f.getName()) {
            case "mEdgeGlowTop":
                f.setAccessible(true);
                edgeGlowTop = f;
                break;
            case "mEdgeGlowBottom":
                f.setAccessible(true);
                edgeGlowBottom = f;
                break;
        }
    }
    SCROLL_VIEW_FIELD_EDGE_GLOW_TOP = edgeGlowTop;
    SCROLL_VIEW_FIELD_EDGE_GLOW_BOTTOM = edgeGlowBottom;

    for (Field f : CLASS_LIST_VIEW.getDeclaredFields()) {
        switch (f.getName()) {
            case "mEdgeGlowTop":
                f.setAccessible(true);
                edgeGlowTop = f;
                break;
            case "mEdgeGlowBottom":
                f.setAccessible(true);
                edgeGlowBottom = f;
                break;
        }
    }
    LIST_VIEW_FIELD_EDGE_GLOW_TOP = edgeGlowTop;
    LIST_VIEW_FIELD_EDGE_GLOW_BOTTOM = edgeGlowBottom;

    for (Field f : CLASS_NESTED_SCROLL_VIEW.getDeclaredFields()) {
        switch (f.getName()) {
            case "mEdgeGlowTop":
                f.setAccessible(true);
                edgeGlowTop = f;
                break;
            case "mEdgeGlowBottom":
                f.setAccessible(true);
                edgeGlowBottom = f;
                break;
        }
    }
    for (Method m : CLASS_NESTED_SCROLL_VIEW.getDeclaredMethods()) {
        switch (m.getName()) {
            case "ensureGlows":
                m.setAccessible(true);
                ensureGlowTop = m;
                break;
        }
    }
    NESTED_SCROLL_VIEW_FIELD_EDGE_GLOW_TOP = edgeGlowTop;
    NESTED_SCROLL_VIEW_FIELD_EDGE_GLOW_BOTTOM = edgeGlowBottom;
    NESTED_SCROLL_VIEW_METHOD_ENSURE_GLOWS = ensureGlowTop;

    for (Field f : CLASS_RECYCLER_VIEW.getDeclaredFields()) {
        switch (f.getName()) {
            case "mTopGlow":
                f.setAccessible(true);
                edgeGlowTop = f;
                break;
            case "mBottomGlow":
                f.setAccessible(true);
                edgeGlowBottom = f;
                break;
        }
    }
    for (Method m : CLASS_RECYCLER_VIEW.getDeclaredMethods()) {
        switch (m.getName()) {
            case "ensureTopGlow":
                m.setAccessible(true);
                ensureGlowTop = m;
                break;
            case "ensureBottomGlow":
                m.setAccessible(true);
                ensureGlowBottom = m;
                break;
        }
    }
    RECYCLER_VIEW_FIELD_EDGE_GLOW_TOP = edgeGlowTop;
    RECYCLER_VIEW_FIELD_EDGE_GLOW_BOTTOM = edgeGlowBottom;
    RECYCLER_VIEW_METHOD_ENSURE_GLOW_TOP = ensureGlowTop;
    RECYCLER_VIEW_METHOD_ENSURE_GLOW_BOTTOM = ensureGlowBottom;

    for (Field f : CLASS_VIEW_PAGER.getDeclaredFields()) {
        switch (f.getName()) {
            case "mLeftEdge":
                f.setAccessible(true);
                edgeGlowTop = f;
                break;
            case "mRightEdge":
                f.setAccessible(true);
                edgeGlowBottom = f;
                break;
        }
    }
    VIEW_PAGER_FIELD_EDGE_GLOW_LEFT = edgeGlowTop;
    VIEW_PAGER_FIELD_EDGE_GLOW_RIGHT = edgeGlowBottom;

}

public static void setEdgeGlowColor(AbsListView listView, int color) {

    try {
        setEdgeEffectColor(LIST_VIEW_FIELD_EDGE_GLOW_TOP.get(listView), color);
        setEdgeEffectColor(LIST_VIEW_FIELD_EDGE_GLOW_BOTTOM.get(listView), color);
    } catch (Exception e) {
        e.printStackTrace();
    }

}

public static void setEdgeGlowColor(ScrollView scrollView, int color) {

    try {
        setEdgeEffectColor(SCROLL_VIEW_FIELD_EDGE_GLOW_TOP.get(scrollView), color);
        setEdgeEffectColor(SCROLL_VIEW_FIELD_EDGE_GLOW_BOTTOM.get(scrollView), color);
    } catch (Exception e) {
        e.printStackTrace();
    }

}

public static void setEdgeGlowColor(final ViewPager viewPager, final int color) {

    try {
        setEdgeEffectColor(VIEW_PAGER_FIELD_EDGE_GLOW_LEFT.get(viewPager), color);
        setEdgeEffectColor(VIEW_PAGER_FIELD_EDGE_GLOW_RIGHT.get(viewPager), color);
    } catch (final Exception e) {
        e.printStackTrace();
    }

}

public static void setEdgeGlowColor(NestedScrollView scrollView, int color) {

    try {
        NESTED_SCROLL_VIEW_METHOD_ENSURE_GLOWS.invoke(scrollView);
        setEdgeEffectColor(NESTED_SCROLL_VIEW_FIELD_EDGE_GLOW_TOP.get(scrollView), color);
        setEdgeEffectColor(NESTED_SCROLL_VIEW_FIELD_EDGE_GLOW_BOTTOM.get(scrollView), color);
    } catch (final Exception | NoClassDefFoundError e) {
        e.printStackTrace();
    }

}

public static void setEdgeGlowColor(final RecyclerView recyclerView, final int color) {

    try {
        RECYCLER_VIEW_METHOD_ENSURE_GLOW_TOP.invoke(recyclerView);
        RECYCLER_VIEW_METHOD_ENSURE_GLOW_BOTTOM.invoke(recyclerView);
        setEdgeEffectColor(RECYCLER_VIEW_FIELD_EDGE_GLOW_TOP.get(recyclerView), color);
        setEdgeEffectColor(RECYCLER_VIEW_FIELD_EDGE_GLOW_BOTTOM.get(recyclerView), color);
    } catch (final Exception | NoClassDefFoundError e) {
        e.printStackTrace();
    }

}

private static void setEdgeEffectColor(Object object, int color) {

    try {
        EdgeEffect edgeEffect = null;
        if (object instanceof EdgeEffectCompat) {
            final Field fEdgeEffect = object.getClass().getDeclaredField("mEdgeEffect");
            fEdgeEffect.setAccessible(true);
            edgeEffect = (EdgeEffect) fEdgeEffect.get(object);
        } else if (object instanceof EdgeEffect) {
            edgeEffect = (EdgeEffect) object;
        }

        if (Build.VERSION.SDK_INT >= 21) {
            edgeEffect.setColor(color);
        } else {
            for (String name : new String[] {"mEdge", "mGlow"}) {
                final Field field = EdgeEffect.class.getDeclaredField(name);
                field.setAccessible(true);
                final Drawable drawable = (Drawable) field.get(edgeEffect);
                drawable.setColorFilter(color, PorterDuff.Mode.SRC_IN);
                drawable.setCallback(null);
            }
        }
    } catch (final Exception | NoClassDefFoundError e) {
        e.printStackTrace();
    }

}

}

如果您正在使用ProGuard，请不要忘记添加这些规则（不要重命名要使用反射工作的字段）：

-keepnames class android.widget.ScrollView { *; }
-keepnames class android.widget.AbsListView { *; }
-keepnames class android.support.v4.widget.NestedScrollView { *; }
-keepnames class android.support.v7.widget.RecyclerView { *; }
-keepnames class android.support.v4.view.ViewPager { *; }
-keepnames class android.widget.EdgeEffect { *; }
-keepnames class android.support.v4.widget.EdgeEffectCompat { *; }