ListView滑动隐藏显示ToolBar的实例

<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent"> <ListView  android:layout_width="match_parent"  android:layout_height="match_parent"  android:background="#f2f2f2"  android:divider="#abcdee"  android:dividerHeight="1px"  android:id="@+id/listView">   </ListView> <!--ToolBar--> <android.support.v7.widget.Toolbar  android:layout_width="match_parent"  android:layout_height="wrap_content"  android:background="#4097e6"  android:id="@+id/toolBar">   </android.support.v7.widget.Toolbar> </RelativeLayout>

package com.research.gong.android_view_research;import android.animation.ObjectAnimator;import android.app.Activity;import android.os.Bundle;import android.support.v7.widget.Toolbar;import android.view.MotionEvent;import android.view.View;import android.view.ViewConfiguration;import android.widget.AbsListView;import android.widget.ArrayAdapter;import android.widget.ListView;public class MainActivity extends Activity { private ListView listView; String[] datas = {"A1", "A2", "A3", "A4", "A5", "A6", "A7", "A8", "A9", "A10",   "A11", "A12", "A13", "A14", "A15", "A16", "A17", "A18", "A19", "A20"}; private float scaledTouchSlop; private float firstY = 0; private Toolbar toolbar; private ObjectAnimator animtor; @Override protected void onCreate(Bundle savedInstanceState) {  super.onCreate(savedInstanceState);  setContentView(R.layout.activity_main);  toolbar = (Toolbar) findViewById(R.id.toolBar);  listView = (ListView) findViewById(R.id.listView);  /**   * 添加一个HeadView避免第一个Item被ToolBar遮挡   * 必须在setAdapter之前进行设置   */  initHeadView();  listView.setAdapter(new ArrayAdapter<>(this, android.R.layout.simple_list_item_1, datas));  //判断认为是滑动的最小距离(乘以系数调整滑动灵敏度)  scaledTouchSlop = ViewConfiguration.get(this).getScaledTouchSlop()*3.0f;  /**   * 设置触摸事件   */  listView.setOnTouchListener(new View.OnTouchListener() {   private float currentY;   private int direction=-1;   private boolean mShow = true;   @Override   public boolean onTouch(View v, MotionEvent event) {    switch (event.getAction()) {     case MotionEvent.ACTION_DOWN:      firstY = event.getY();      break;     case MotionEvent.ACTION_MOVE:      currentY = event.getY();      //向下滑动      if (currentY - firstY > scaledTouchSlop) {       direction = 0;      }      //向上滑动      else if (firstY - currentY > scaledTouchSlop) {       direction = 1;      }      //如果是向上滑动，并且ToolBar是显示的，就隐藏ToolBar      if (direction == 1) {       if (mShow) {        toobarAnim(1);        mShow = !mShow;       }      } else if (direction == 0) {       if (!mShow) {        toobarAnim(0);        mShow = !mShow;       }      }      break;     case MotionEvent.ACTION_UP:      break;    }    return false;//注意此处不能返回true，因为如果返回true,onTouchEvent就无法执行，导致的后果是ListView无法滑动   }  }); } /**  * 设置头布局，注意：这个头布局的高度要和ToolBar的高度一致  */ public void initHeadView() {  View view = new View(this);  //abc_action_bar_default_height_material获取系统ActionBar的高度  AbsListView.LayoutParams params = new AbsListView.LayoutParams    (AbsListView.LayoutParams.MATCH_PARENT,      (int) getResources().getDimension(R.dimen.abc_action_bar_default_height_material));  view.setLayoutParams(params);  listView.addHeaderView(view); } /**  * ToolBar显示隐藏动画  * @param direction  */ public void toobarAnim(int direction) {  //开始新的动画之前要先取消以前的动画  if (animtor != null && animtor.isRunning()) {   animtor.cancel();  }  //toolbar.getTranslationY()获取的是Toolbar距离自己顶部的距离  float translationY=toolbar.getTranslationY();  if (direction == 0) {   animtor = ObjectAnimator.ofFloat(toolbar, "translationY", translationY, 0);  } else if (direction == 1) {   animtor = ObjectAnimator.ofFloat(toolbar, "translationY", translationY, -toolbar.getHeight());  }  animtor.start(); }}