RecyclerVIew实现悬浮吸顶效果

<?xml version="1.0" encoding="utf-8"?><FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"  android:layout_width="match_parent"  android:layout_height="match_parent">  <android.support.v7.widget.RecyclerView    android:id="@+id/recycle"    android:layout_width="match_parent"    android:layout_height="match_parent" />  <TextView    android:id="@+id/tv_sticky_header_view"    android:layout_width="match_parent"    android:layout_height="50dp"    android:background="#EFFAE7"    android:gravity="center"    android:text="吸顶文本1" />  <!--<include layout="@layout/layout_sticky_header_view"/>--></FrameLayout>

<?xml version="1.0" encoding="utf-8"?><FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"  android:layout_width="match_parent"  android:layout_height="match_parent"  android:orientation="vertical">  <RelativeLayout    android:layout_marginLeft="5dp"    android:layout_marginRight="5dp"    android:id="@+id/rl_content_wrapper"    android:layout_width="match_parent"    android:layout_height="30dp">    <TextView      android:id="@+id/name"      android:layout_centerVertical="true"      android:layout_width="wrap_content"      android:layout_height="wrap_content" />    <TextView      android:id="@+id/auto"      android:layout_centerVertical="true"      android:layout_width="wrap_content"      android:layout_height="wrap_content"      android:layout_alignParentRight="true" />    <View      android:layout_width="match_parent"      android:layout_height="1dp"      android:layout_alignParentBottom="true"      android:background="#ffffff"/>  </RelativeLayout>  <TextView    android:id="@+id/tv_sticky_header_view"    android:layout_width="match_parent"    android:layout_height="50dp"    android:background="#EFFAE7"    android:gravity="center"    android:text="吸顶文本1" /></FrameLayout>

public class MainActivity extends AppCompatActivity {  private TextView tvStickyHeaderView;  private RecyclerView recyclerView;  @Override  protected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_main);    initView();    initListener();  }  /**   * 初始化View   */  private void initView() {    recyclerView = (RecyclerView) findViewById(R.id.recycle);    tvStickyHeaderView = (TextView) findViewById(R.id.tv_sticky_header_view);    recyclerView.setLayoutManager(new LinearLayoutManager(this));    recyclerView.setAdapter(new StickyExampleAdapter(this, getData()));  }  /**   * 初始化Listener   */  private void initListener() {    recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {      @Override      public void onScrolled(RecyclerView recyclerView, int dx, int dy) {        super.onScrolled(recyclerView, dx, dy);        View stickview = recyclerView.findChildViewUnder(0, 0);        if (stickview != null && stickview.getContentDescription() != null) {          if (!TextUtils.equals(tvStickyHeaderView.getText(), stickview.getContentDescription())) {            tvStickyHeaderView.setText(stickview.getContentDescription());          }        }        View transInfoView = recyclerView.findChildViewUnder(            0, tvStickyHeaderView.getHeight() + 1);        if (transInfoView.getTag() != null) {          int transViewStatus = (int) transInfoView.getTag();          int top = transInfoView.getTop();          if (transViewStatus == StickyExampleAdapter.HAS_STICKY_VIEW) {            if (top > 0) {              int dealtY = top - tvStickyHeaderView.getMeasuredHeight();              tvStickyHeaderView.setTranslationY(dealtY);            } else {              tvStickyHeaderView.setTranslationY(0);            }          } else if (transViewStatus == StickyExampleAdapter.NONE_STICKY_VIEW) {            tvStickyHeaderView.setTranslationY(0);          }        }      }    });  }  public List<StickyBean> getData() {    List<StickyBean> stickyExampleModels = new ArrayList<>();    for (int index = 0; index < 100; index++) {      if (index < 15) {        stickyExampleModels.add(new StickyBean(            "吸顶文本1", "name" + index, "gender" + index));      } else if (index < 25) {        stickyExampleModels.add(new StickyBean(            "吸顶文本2", "name" + index, "gender" + index));      } else if (index < 35) {        stickyExampleModels.add(new StickyBean(            "吸顶文本3", "name" + index, "gender" + index));      } else {        stickyExampleModels.add(new StickyBean(            "吸顶文本4", "name" + index, "gender" + index));      }    }    return stickyExampleModels;  }}

public class StickyExampleAdapter extends RecyclerView.Adapter<StickyExampleAdapter.RecyclerViewHolder> {  //第一个吸顶  private static final int FIRST_STICKY_VIEW = 1;  //别的吸顶  static final int HAS_STICKY_VIEW = 2;  //正常View  static final int NONE_STICKY_VIEW = 3;  private final LayoutInflater mInflate;  private final List<StickyBean> datas;  StickyExampleAdapter(Context context, List<StickyBean> datas){    mInflate = LayoutInflater.from(context);    this.datas = datas;  }  @Override  public RecyclerViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {    View inflate = mInflate.inflate(R.layout.item_ui, parent, false);    return new RecyclerViewHolder(inflate);  }  @Override  public void onBindViewHolder(RecyclerViewHolder holder, int position) {    StickyBean stickyBean = datas.get(position);    holder.tvName.setText(stickyBean.name);    holder.tvGender.setText(stickyBean.autor);    if (position == 0) {      holder.tvStickyHeader.setVisibility(View.VISIBLE);      holder.tvStickyHeader.setText(stickyBean.sticky);      holder.itemView.setTag(FIRST_STICKY_VIEW);    } else {      if (!TextUtils.equals(stickyBean.sticky, datas.get(position - 1).sticky)) {        holder.tvStickyHeader.setVisibility(View.VISIBLE);        holder.tvStickyHeader.setText(stickyBean.sticky);        holder.itemView.setTag(HAS_STICKY_VIEW);      } else {        holder.tvStickyHeader.setVisibility(View.GONE);        holder.itemView.setTag(NONE_STICKY_VIEW);      }    }    //通过此处设置ContentDescription，作为内容描述，可以通过getContentDescription取出，功效跟setTag差不多。    holder.itemView.setContentDescription(stickyBean.sticky);  }  @Override  public int getItemCount() {    return datas == null ? 0 : datas.size();  }  public class RecyclerViewHolder extends RecyclerView.ViewHolder{    TextView tvStickyHeader;    RelativeLayout rlContentWrapper;    TextView tvName;    TextView tvGender;    RecyclerViewHolder(View itemView) {      super(itemView);      tvStickyHeader = (TextView) itemView.findViewById(R.id.tv_sticky_header_view);      rlContentWrapper = (RelativeLayout) itemView.findViewById(R.id.rl_content_wrapper);      tvName = (TextView) itemView.findViewById(R.id.name);      tvGender = (TextView) itemView.findViewById(R.id.auto);    }  }}

public class StickyBean {  public String name;  public String autor;  public String sticky;  public StickyBean(String sticky, String name, String autor) {    this.sticky = sticky;    this.name = name;    this.autor = autor;  }}

apply plugin: 'com.android.application'android {  compileSdkVersion 26  buildToolsVersion "25.0.3"  defaultConfig {    applicationId "com.lg.floating"    minSdkVersion 15    targetSdkVersion 26    versionCode 1    versionName "1.0"    testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"  }  buildTypes {    release {      minifyEnabled false      proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'    }  }}dependencies {  compile fileTree(dir: 'libs', include: ['*.jar'])  androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {    exclude group: 'com.android.support', module: 'support-annotations'  })  compile 'com.android.support:appcompat-v7:26.0.0-alpha1'  compile 'com.android.support:recyclerview-v7:23.1.0'  testCompile 'junit:junit:4.12'}