我创建了一个应用程序，其中操作栏中有4个选项卡。 我使用了manuelpeinado.fadingactionbar。
滚动时，它适用于第一个标签，但是当我切换到第二个标签颜色时没有变化。 我查看了logcat并找到了“mActionBarBackgroundDrawable.setAlpha（newAlpha）;”的值。 正在变化，但颜色没有变化。 它是我在stackoverflow上的第一个问题，如果我错过了什么，那么对不起。 感谢ADV。public class FadingActionBarHelper {
protected static final String TAG = "FadingActionBarHelper";
private Drawable mActionBarBackgroundDrawable;
private FrameLayout mHeaderContainer;
private int mActionBarBackgroundResId;
private int mHeaderLayoutResId;
private View mHeaderView;
private int mContentLayoutResId;
private View mContentView;
private ActionBar mActionBar;
private LayoutInflater mInflater;
private boolean mLightActionBar;
private boolean mUseParallax = true;
private int mLastDampedScroll;
private int mLastHeaderHeight = -1;
private ViewGroup mContentContainer;
private ViewGroup mScrollView;
private boolean mFirstGlobalLayoutPerformed;
private View mMarginView;
private View mListViewBackgroundView;
private double speed = 0;
public FadingActionBarHelper actionBarBackground(int drawableResId) {
mActionBarBackgroundResId = drawableResId;
return this;
}
public FadingActionBarHelper actionBarBackground(Drawable drawable) {
mActionBarBackgroundDrawable = drawable;
return this;
}
public FadingActionBarHelper headerLayout(int layoutResId) {
mHeaderLayoutResId = layoutResId;
return this;
}
public FadingActionBarHelper headerView(View view) {
mHeaderView = view;
return this;
}
public FadingActionBarHelper contentLayout(int layoutResId) {
mContentLayoutResId = layoutResId;
return this;
}
public FadingActionBarHelper contentView(View view) {
mContentView = view;
return this;
}
public FadingActionBarHelper lightActionBar(boolean value) {
mLightActionBar = value;
return this;
}
public FadingActionBarHelper parallax(boolean value) {
mUseParallax = value;
return this;
}
public double getSpeed(){
return speed;
}
public View createView(Context context) {
return createView(LayoutInflater.from(context));
}
public View createView(LayoutInflater inflater) {
//
// Prepare everything
mInflater = inflater;
if (mContentView == null) {
mContentView = inflater.inflate(mContentLayoutResId, null);
}
if (mHeaderView == null) {
mHeaderView = inflater.inflate(mHeaderLayoutResId, mHeaderContainer, false);
}
//
// See if we are in a ListView or ScrollView scenario
ListView listView = (ListView) mContentView.findViewById(android.R.id.list);
View root;
if (listView != null) {
root = createListView(listView);
} else {
root = createScrollView();
}
// Use measured height here as an estimate of the header height, later on after the layout is complete
// we'll use the actual height
int widthMeasureSpec = MeasureSpec.makeMeasureSpec(LayoutParams.MATCH_PARENT, MeasureSpec.EXACTLY);
int heightMeasureSpec = MeasureSpec.makeMeasureSpec(LayoutParams.WRAP_CONTENT, MeasureSpec.EXACTLY);
mHeaderView.measure(widthMeasureSpec, heightMeasureSpec);
updateHeaderHeight(mHeaderView.getMeasuredHeight());
root.getViewTreeObserver().addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
@Override
public void onGlobalLayout() {
int headerHeight = mHeaderContainer.getHeight();
if (!mFirstGlobalLayoutPerformed && headerHeight != 0) {
updateHeaderHeight(headerHeight);
mFirstGlobalLayoutPerformed = true;
}
}
});
return root;
}
public void initActionBar(Activity activity) {
mActionBar = getActionBar(activity);
if (mActionBarBackgroundDrawable == null) {
mActionBarBackgroundDrawable = activity.getResources().getDrawable(mActionBarBackgroundResId);
}
mActionBar.setBackgroundDrawable(mActionBarBackgroundDrawable);
if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.JELLY_BEAN) {
mActionBarBackgroundDrawable.setCallback(mDrawableCallback);
Toast.makeText(activity, "Inside initActionBar version less than jellybean", Toast.LENGTH_SHORT);
}
Toast.makeText(activity, " Inside initActionBar ", Toast.LENGTH_SHORT);
mActionBarBackgroundDrawable.setAlpha(0);
}
protected ActionBar getActionBar(Activity activity) {
return activity.getActionBar();
}
private Drawable.Callback mDrawableCallback = new Drawable.Callback() {
@Override
public void invalidateDrawable(Drawable who) {
mActionBar.setBackgroundDrawable(who);
}
@Override
public void scheduleDrawable(Drawable who, Runnable what, long when) {
}
@Override
public void unscheduleDrawable(Drawable who, Runnable what) {
}
};
private View createScrollView() {
mScrollView = (ViewGroup) mInflater.inflate(R.layout.fab__scrollview_container, null);
NotifyingScrollView scrollView = (NotifyingScrollView) mScrollView.findViewById(R.id.fab__scroll_view);
scrollView.setOnScrollChangedListener(mOnScrollChangedListener);
mContentContainer = (ViewGroup) mScrollView.findViewById(R.id.fab__container);
mContentContainer.addView(mContentView);
mHeaderContainer = (FrameLayout) mScrollView.findViewById(R.id.fab__header_container);
initializeGradient(mHeaderContainer);
mHeaderContainer.addView(mHeaderView, 0);
mMarginView = mContentContainer.findViewById(R.id.fab__content_top_margin);
return mScrollView;
}
private NotifyingScrollView.OnScrollChangedListener mOnScrollChangedListener = new NotifyingScrollView.OnScrollChangedListener() {
public void onScrollChanged(ScrollView who, int l, int t, int oldl, int oldt) {
onNewScroll(t);
}
};
private View createListView(ListView listView) {
mContentContainer = (ViewGroup) mInflater.inflate(R.layout.fab__listview_container, null);
mContentContainer.addView(mContentView);
mHeaderContainer = (FrameLayout) mContentContainer.findViewById(R.id.fab__header_container);
initializeGradient(mHeaderContainer);
mHeaderContainer.addView(mHeaderView, 0);
mMarginView = new View(listView.getContext());
mMarginView.setLayoutParams(new AbsListView.LayoutParams(LayoutParams.MATCH_PARENT, 0));
listView.addHeaderView(mMarginView, null, false);
// Make the background as high as the screen so that it fills regardless of the amount of scroll.
mListViewBackgroundView = mContentContainer.findViewById(R.id.fab__listview_background);
FrameLayout.LayoutParams params = (FrameLayout.LayoutParams) mListViewBackgroundView.getLayoutParams();
params.height = Utils.getDisplayHeight(listView.getContext());
mListViewBackgroundView.setLayoutParams(params);
listView.setOnScrollListener(new CustomScrollListener());
return mContentContainer;
}
private class CustomScrollListener implements OnScrollListener{
private int previousFirstVisibleItem = 0;
private long previousEventTime = 0, currTime, timeToScrollOneElement;
@Override
public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
View topChild = null;
topChild = view.getChildAt(0);
if (topChild == null) {
onNewScroll(0);
} else if (topChild != mMarginView) {
onNewScroll(mHeaderContainer.getHeight());
} else {
onNewScroll(-topChild.getTop());
}
if (previousFirstVisibleItem != firstVisibleItem) {
currTime = System.currentTimeMillis();
timeToScrollOneElement = currTime - previousEventTime;
speed = ((double) 1 / timeToScrollOneElement) * 1000;
previousFirstVisibleItem = firstVisibleItem;
previousEventTime = currTime;
}
}
@Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
}
}
private int mLastScrollPosition ;
private void onNewScroll(int scrollPosition) {
if (mActionBar == null) {
return;
}
int currentHeaderHeight = mHeaderContainer.getHeight();
if (currentHeaderHeight != mLastHeaderHeight) {
updateHeaderHeight(currentHeaderHeight); // to make position of header at its default pos.
}
int headerHeight = currentHeaderHeight - mActionBar.getHeight();
float ratio = (float) Math.min(Math.max(scrollPosition, 0), headerHeight) / headerHeight;
int newAlpha = (int) (ratio * 255);
Log.d(" Inside onNewScroll() ", ""+newAlpha);
mActionBarBackgroundDrawable.setAlpha(newAlpha);
// addParallaxEffect(scrollPosition);
}
private void addParallaxEffect(int scrollPosition) {
float damping = mUseParallax ? 0.5f : 1.0f;
int dampedScroll = (int) (scrollPosition * damping);
int offset = mLastDampedScroll - dampedScroll;
Log.d(" Inside addParallaxEffect() ", ""+offset);
mHeaderContainer.offsetTopAndBottom(offset);
if (mListViewBackgroundView != null) {
offset = mLastScrollPosition - scrollPosition;
mListViewBackgroundView.offsetTopAndBottom(offset);
}
if (mFirstGlobalLayoutPerformed) {
mLastScrollPosition = scrollPosition;
mLastDampedScroll = dampedScroll;
}
}
private void updateHeaderHeight(int headerHeight) {
ViewGroup.LayoutParams params = (ViewGroup.LayoutParams) mMarginView.getLayoutParams();
params.height = headerHeight;
mMarginView.setLayoutParams(params);
if (mListViewBackgroundView != null) {
FrameLayout.LayoutParams params2 = (FrameLayout.LayoutParams) mListViewBackgroundView.getLayoutParams();
params2.topMargin = headerHeight;
mListViewBackgroundView.setLayoutParams(params2);
}
mLastHeaderHeight = headerHeight;
}
private void initializeGradient(ViewGroup headerContainer) {
View gradientView = headerContainer.findViewById(R.id.fab__gradient);
int gradient = R.drawable.fab__gradient;
if (mLightActionBar) {
gradient = R.drawable.fab__gradient_light;
}
gradientView.setBackgroundResource(gradient);
}
}