Fragment进入和退出动画

activity+fragment的软件框架中，多级页面的fragment一般都有动画效果，现在将动画的实现方法总结如下。

方法一

• 重写fragment 的onCreateAnimation方法。
  在fragment的基类中，重写onCreateAnimation方法，使得fragment有进入和退出的动画效果。

public abstract class ChildFragment extends Fragment {

    public IContainerFragment getContainerFragment() {
        Fragment parentFragment = getParentFragment();
        if (parentFragment instanceof IContainerFragment) {
            return (IContainerFragment) parentFragment;
        }
        return null;
    }

    protected boolean addFragmentToStack(ChildFragment fragment) {
        IContainerFragment containerFragment = getContainerFragment();
        if (containerFragment == null) {
            return false;
        }
        containerFragment.addFragmentToStack(fragment);
        return true;
    }

    @Override
    public Animation onCreateAnimation(int transit, boolean enter, int nextAnim) {
        TranslateAnimation animation = null;
        if (transit == FragmentTransaction.TRANSIT_FRAGMENT_OPEN) {
            if (enter) {
                animation = new TranslateAnimation(Animation.RELATIVE_TO_SELF, 1, Animation.RELATIVE_TO_SELF, 0,
                        Animation.RELATIVE_TO_SELF, 0, Animation.RELATIVE_TO_SELF, 0);
            } else {
                animation = new TranslateAnimation(Animation.RELATIVE_TO_SELF, 0, Animation.RELATIVE_TO_SELF, -1,
                        Animation.RELATIVE_TO_SELF, 0, Animation.RELATIVE_TO_SELF, 0);
            }
        } else if (FragmentTransaction.TRANSIT_FRAGMENT_CLOSE == transit) {
            if (enter) {
                animation = new TranslateAnimation(Animation.RELATIVE_TO_SELF, -1, Animation.RELATIVE_TO_SELF, 0,
                        Animation.RELATIVE_TO_SELF, 0, Animation.RELATIVE_TO_SELF, 0);
            } else {
                animation = new TranslateAnimation(Animation.RELATIVE_TO_SELF, 0, Animation.RELATIVE_TO_SELF, 1,
                        Animation.RELATIVE_TO_SELF, 0, Animation.RELATIVE_TO_SELF, 0);
            }
        }
        if (animation == null) {
            animation = new TranslateAnimation(0, 0, 0, 0);
        }
        animation.setDuration(300);
        return animation;
    }
}

注意，该方案，进入fragment用如下方法

 @Override
    public boolean addFragmentToStack(ChildFragment fragment) {
        if (!isResumed() || !isAdded()) {
            return false;
        }
        String simpleName = fragment.getClass().getSimpleName();
        FragmentTransaction ft = getChildFragmentManager().beginTransaction();
        ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN);
        ft.replace(getContainerId(), fragment, simpleName);
        ft.addToBackStack(null);
        ft.commit();
        getChildFragmentManager().executePendingTransactions();
        return true;
    }

退出fragment的方法为 getActivity().onBackPressed();

@Override
    public void onClick(View view) {
        switch (view.getId()) {
            case R.id.title_bar_left_btn:
                getActivity().onBackPressed();
                break;

        }
    }

方法二

使用Fragmentmanager 的add方法，commit之前设置动画

/**
         * 弹出Fragment堆栈
         */
        private static void onPopBackStack(FragmentActivity context) {
            if(context == null) {
                android.util.Log.e("", "Context is null.");
                return;
            }
            FragmentManager manager = context.getSupportFragmentManager();
            if(manager == null) {
                android.util.Log.e("", "FragmentManager is null.");
                return;
            }
            Fragment lastElement = getActiveFragment(context);
            if(lastElement != null && lastElement.isAdded()) {
                lastElement.onHiddenChanged(false);
            }
            manager.beginTransaction()
           .setCustomAnimations(
               R.anim.slide_left_out,R.anim.slide_right_out)
                    .remove(lastElement)
                    .commitAllowingStateLoss();
            manager.popBackStack();

            disableFragmentView(false,context);
        }

/**
         * 添加Fragment到堆栈
         * @param fragmentTag   Tag标记
         * @param fragment      Fragment实例
         */
        public  static void addToBackStack(FragmentActivity context, String fragmentTag, Fragment fragment) {
            disableFragmentView(true,context);
            FragmentManager manager = context.getSupportFragmentManager();

            manager.beginTransaction()
           .setCustomAnimations(
                    R.anim.slide_right_in,
                R.anim.slide_left_out)
                    .add(R.id.content_fragment, fragment,fragmentTag)
                    .addToBackStack(fragmentTag).commitAllowingStateLoss();
            disableContentFragment(context, true);
        }

slide_left_in

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android" >
    <translate
        android:duration="300"
        android:toXDelta="0.0"
        android:fromXDelta="-100.0%p" />
</set>

slide_left_out

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android" >
    <translate
        android:duration="300"
        android:fromXDelta="0.0"
        android:toXDelta="-100.0%p" />
</set>

slide_right_in

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android" >
    <translate
        android:duration="300"
        android:fromXDelta="100.0%p"
        android:toXDelta="0.0" />
</set>

slide_right_out

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android" >
    <translate
        android:duration="300"
        android:toXDelta="100.0%p"
        android:fromXDelta="0.0" />
</set>