仅在折叠时显示

Question

我尝试了SetExpandedTitleColor和SetCollapsedTitleColor（切换到和从透明的），但没有成功。我也看不到任何内置的方法来做我想要的事情。

我只想在CollapsingToolbarLayout完全折叠时显示标题，否则，我需要隐藏它。

Answer 1

您可以将onoffsetChangedListener添加到AppBarLayout中，以确定何时折叠或展开CollapsingToolbarLayout并设置其标题。

final CollapsingToolbarLayout collapsingToolbarLayout = (CollapsingToolbarLayout) findViewById(R.id.collapsingToolbarLayout);
AppBarLayout appBarLayout = (AppBarLayout) findViewById(R.id.appBarLayout);
appBarLayout.addOnOffsetChangedListener(new AppBarLayout.OnOffsetChangedListener() {
    boolean isShow = true;
    int scrollRange = -1;

    @Override
    public void onOffsetChanged(AppBarLayout appBarLayout, int verticalOffset) {
        if (scrollRange == -1) {
            scrollRange = appBarLayout.getTotalScrollRange();
        }
        if (scrollRange + verticalOffset == 0) {
            collapsingToolbarLayout.setTitle("Title");
            isShow = true;
        } else if(isShow) {
            collapsingToolbarLayout.setTitle(" ");//careful there should a space between double quote otherwise it wont work 
            isShow = false;
        }
    }
});

var isShow = true
var scrollRange = -1
appBarLayout.addOnOffsetChangedListener(AppBarLayout.OnOffsetChangedListener { barLayout, verticalOffset ->
    if (scrollRange == -1){
        scrollRange = barLayout?.totalScrollRange!!
    }
    if (scrollRange + verticalOffset == 0){
        collapsingToolbarLayout.title = "Title Collapse"
        isShow = true
    } else if (isShow){
        collapsingToolbarLayout.title = " " //careful there should a space between double quote otherwise it wont work
        isShow = false
    }
})