Android CollapsingToolbarLayout 折叠监听器

Question

我将 CollapsingToolBarLayout 与 AppBarLayout 和 CoordinatorLayout 一起使用，它们完全可以正常工作。我将我的 Toolbar 设置为在向上滚动时固定，我想知道是否有办法更改工具栏的标题文本，当 CollapsingToolBarLayout 它已折叠。

总结一下，当滚动和展开时，我想要两个不同的标题。

提前谢谢大家

Answer 1

我分享了基于@Frodio Beggins 和@Nifhel 代码的完整实现:​​

public abstract class AppBarStateChangeListener implements AppBarLayout.OnOffsetChangedListener {

    public enum State {
        EXPANDED,
        COLLAPSED,
        IDLE
    }

    private State mCurrentState = State.IDLE;

    @Override
    public final void onOffsetChanged(AppBarLayout appBarLayout, int i) {
        if (i == 0) {
            if (mCurrentState != State.EXPANDED) {
                onStateChanged(appBarLayout, State.EXPANDED);
            }
            mCurrentState = State.EXPANDED;
        } else if (Math.abs(i) >= appBarLayout.getTotalScrollRange()) {
            if (mCurrentState != State.COLLAPSED) {
                onStateChanged(appBarLayout, State.COLLAPSED);
            }
            mCurrentState = State.COLLAPSED;
        } else {
            if (mCurrentState != State.IDLE) {
                onStateChanged(appBarLayout, State.IDLE);
            }
            mCurrentState = State.IDLE;
        }
    }

    public abstract void onStateChanged(AppBarLayout appBarLayout, State state);
}

然后你就可以使用它了:

appBarLayout.addOnOffsetChangedListener(new AppBarStateChangeListener() {
    @Override
    public void onStateChanged(AppBarLayout appBarLayout, State state) {
        Log.d("STATE", state.name());
    }
});