我编写了实用程序类 EdgeChanger，它是我之前的帖子 @Jared Hummler code 和 @Eugen Pechanec code 的混合体。
这个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
并且在使用 AppCompat 时可与 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。
仅当您想在 onCreate() 之后更改边缘发光颜色时才使用此选项，否则您应该使用 setTheme 和具有不同颜色属性 colorPrimary 或 colorEdgeEffect 的不同主题。
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();
}
}
}
如果您使用 ProGuard，请不要忘记添加这些规则（以不使用反射重命名您希望使用的字段）：
-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 { *; }