public class HomeFragment extends Fragment {
@InjectView(R.id.rv_home)
RecyclerView mRvHome;
@InjectView(R.id.home_tv_address)
TextView mHomeTvAddress;
@InjectView(R.id.ll_title_search)
LinearLayout mLlTitleSearch;
@InjectView(R.id.ll_title_container)
LinearLayout mLlTitleContainer;
private View mView;
private List<String> mDatas = new ArrayList<>();
private HomeRvAdapter mHomeRvAdapter;
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
mView = View.inflate(getContext(), R.layout.fragment_home, null);
ButterKnife.inject(this, mView);
mHomeRvAdapter = new HomeRvAdapter(getContext(), mDatas);
//1.设置适配器
mRvHome.setAdapter(mHomeRvAdapter);
//设置布局样式
mRvHome.setLayoutManager(new LinearLayoutManager(getContext(), LinearLayoutManager.VERTICAL, false));
return mView;
}
int sumY;//当前滚动的距离
float distance = 400.00f; //滚动到150.00颜色最深,alpha值最大,临界值
int startbgColor = 0x553190E8;
int endbgColor = 0Xff438bfd;
int bgcolor = 0;//背景色变量
ArgbEvaluator mArgbEvaluator = new ArgbEvaluator();
@Override
public void onActivityCreated(@Nullable Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
// 2 加载数据
LoadData();
mRvHome.addOnScrollListener(new RecyclerView.OnScrollListener() {
@Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
super.onScrolled(recyclerView, dx, dy);
//需要知道y方向滚动多少,累加得到总共滚动多少;
sumY += dy;
if (sumY<0){//没有滚动
bgcolor=startbgColor;
}else if (sumY>distance){//超出渐变范围
bgcolor=endbgColor;
}else {
bgcolor= (int) mArgbEvaluator.evaluate(distance/sumY,startbgColor,endbgColor);
}
mLlTitleContainer.setBackgroundColor(bgcolor);
}
});
}
private void LoadData() {
for (int i = 0; i < 100; i++) {
mDatas.add("我是是----" + i);
mHomeRvAdapter.setDatas(mDatas);
}
}
@Override
public void onDestroyView() {
super.onDestroyView();
ButterKnife.reset(this);
}}