android listview 的弹性滑动 简单demo 实现

　　弹性滑动的效果比较好看。但是 在2.2以下版本中，android 本身没有实现，想要实现这中效果要自己去写
　　前几天在iteye上看见了一个博客给我很大的启示，于是自己动手实验了一下感觉还可以。在这里把我的源码给大家贴上让大家一起分享，希望大家也能提出更好的意见。废话不多说上源码：
　　1.自己些一个MyListview 继承listview 类：

package com.wljie;  import android.content.Context;  import android.graphics.Rect;  import android.util.AttributeSet;  import android.util.Log;  import android.view.GestureDetector;  import android.view.MotionEvent;  import android.view.View;  import android.view.GestureDetector.OnGestureListener;  import android.view.animation.TranslateAnimation;  import android.widget.ListView;  public class MyListView extends ListView {  private Context context;  private boolean outBound = false;  private int distance;  private int firstOut;  private static final String TAG = "wljie";  public MyListView(Context context, AttributeSet attrs) {  super(context, attrs);  this.context = context;  Log.d(TAG, "IN 1");  }  public MyListView(Context context, AttributeSet attrs, int defStyle) {  super(context, attrs, defStyle);  this.context = context;  Log.d(TAG, "IN 2");  }  public MyListView(Context context) {  super(context);  this.context = context;  Log.d(TAG, "IN 3");  }  GestureDetector gestureDetector = new GestureDetector(  new OnGestureListener() {  @Override  public boolean onSingleTapUp(MotionEvent e) {  // TODO Auto-generated method stub  return false;  }  @Override  public void onShowPress(MotionEvent e) {  // TODO Auto-generated method stub  }  /**  * 手势滑动的时候触发  */  @Override  public boolean onScroll(MotionEvent e1, MotionEvent e2,  float distanceX, float distanceY) {  Log.d(TAG, "ENTER onscroll");  int firstPos = getFirstVisiblePosition();  int lastPos = getLastVisiblePosition();  int itemCount = getCount();  // outbound Top  if (outBound && firstPos != 0 && lastPos != (itemCount - 1)) {  scrollTo(0, 0);  return false;  }  View firstView = getChildAt(firstPos);  if (!outBound)  firstOut = (int) e2.getRawY();  if (firstView != null  && (outBound || (firstPos == 0  && firstView.getTop() == 0 && distanceY < 0))) {  // Record the length of each slide  distance = firstOut - (int) e2.getRawY();  scrollTo(0, distance / 2);  return true;  }  // outbound Bottom  return false;  }  @Override  public void onLongPress(MotionEvent e) {  // TODO Auto-generated method stub  }  @Override  public boolean onFling(MotionEvent e1, MotionEvent e2,  float velocityX, float velocityY) {  // TODO Auto-generated method stub  return false;  }  @Override  public boolean onDown(MotionEvent e) {  // TODO Auto-generated method stub  return false;  }  });  @Override  public boolean dispatchTouchEvent(MotionEvent event) {  Log.d(TAG, "dispatchTouchEvent");  int act = event.getAction();  if ((act == MotionEvent.ACTION_UP || act == MotionEvent.ACTION_CANCEL)  && outBound) {  outBound = false;  // scroll back  }  if (!gestureDetector.onTouchEvent(event)) {  outBound = false;  } else {  outBound = true;  }  Rect rect = new Rect();          getLocalVisibleRect(rect);          TranslateAnimation am = new TranslateAnimation( 0, 0, -rect.top, 0);          am.setDuration(300);          startAnimation(am);          scrollTo(0, 0);  return super.dispatchTouchEvent(event);  }  }

　　2.在main.xml 中写入

<?xml version="1.0" encoding="utf-8"?>  <LinearLayout          android:id="@+id/LinearLayout01"          android:layout_width="fill_parent"          android:layout_height="fill_parent"          xmlns:android="http://schemas.android.com/apk/res/android"          >          <com.wljie.MyListView          android:layout_width="wrap_content"                    android:layout_height="wrap_content"                    android:id="@+id/MyListView"/>  </LinearLayout>

　　3.创建一个my_listitem.xml

<?xml version="1.0" encoding="utf-8"?>  <LinearLayout          android:layout_width="fill_parent"          xmlns:android="http://schemas.android.com/apk/res/android"          android:orientation="vertical"          android:layout_height="wrap_content"          android:id="@+id/MyListItem"          android:paddingBottom="3dip"          android:paddingLeft="10dip">          <TextView                  android:layout_height="wrap_content"                  android:layout_width="fill_parent"                  android:id="@+id/ItemTitle"                  android:textSize="30dip">          </TextView>          <TextView                  android:layout_height="wrap_content"                  android:layout_width="fill_parent"                  android:id="@+id/ItemText">          </TextView>  </LinearLayout>

　　4.在Main.java中进行下一步的显示

package com.wljie;      import java.util.ArrayList;      import java.util.HashMap;      import android.app.Activity;      import android.graphics.Rect;      import android.os.Bundle;      import android.view.animation.TranslateAnimation;      import android.widget.SimpleAdapter;      public class Main extends Activity {      /** Called when the activity is first created. */      @Override      public void onCreate(Bundle savedInstanceState) {      super.onCreate(savedInstanceState);      setContentView(R.layout.main);      // 绑定XML中的ListView，作为Item的容器      MyListView list = (MyListView) findViewById(R.id.MyListView);      // 生成动态数组，并且转载数据      ArrayList<HashMap<String, String>> mylist = new ArrayList<HashMap<String, String>>();      for (int i = 0; i < 30; i++) {      HashMap<String, String> map = new HashMap<String, String>();      map.put("ItemTitle", "This is Title.....");      map.put("ItemText", "This is text.....");      mylist.add(map);      }      // 生成适配器，数组===》ListItem      SimpleAdapter mSchedule = new SimpleAdapter(this, // 没什么解释      mylist,// 数据来源      R.layout.my_listitem,// ListItem的XML实现      // 动态数组与ListItem对应的子项      new String[] { "ItemTitle", "ItemText" },      // ListItem的XML文件里面的两个TextView ID      new int[] { R.id.ItemTitle, R.id.ItemText });      // 添加并且显示      list.setAdapter(mSchedule);      }      }

本文出自 “Android小子的” 博客，请务必保留此出处http://androidrigl.blog.51cto.com/7531835/1249509