Android默认的ListView在滚动到顶端或底端，没有很好的提示，下面通过源码来实现弹性效果。
ListView中有一个控制滑动到边缘的处理方法：
protected boolean overScrollBy(int deltaX, int deltaY,int scrollX, int scrollY,int scrollRangeX, int scrollRangeY,int maxOverScrollX, int maxOverScrollY,boolean isTouchEvent)
其中参数maxOverScrollX---Numbers of piexls to overscroll by in either direction along the Y axis.默认为0，修改这个数值就可以实现滑动到顶端的弹性效果。
//为满足多分辨率的需求，通过屏幕的density来计算maxOverScrollY的具体DisplayMetrics metrics = mContext.getResources().getDisplayMetrics();float density = metrics.density;mMaxOverDistance = (int) (density * mMaxOverDistance);
完整的工程
FlexibleListView.java
package sunny.example.ahfourflexiblelistviewtest;import android.annotation.SuppressLint;
import android.content.Context;
import android.util.AttributeSet;
import android.util.DisplayMetrics;
import android.widget.ListView;@SuppressLint("NewApi")
public class FlexibleListView extends ListView {private static int mMaxOverDistance = 50;//将滑动距离改为50，默认为0，无弹性效果private Context mContext;public FlexibleListView(Context context, AttributeSet attrs,int defStyleAttr) {super(context, attrs, defStyleAttr);this.mContext = context;initView();}public FlexibleListView(Context context, AttributeSet attrs) {super(context, attrs);this.mContext = context;initView();}public FlexibleListView(Context context) {super(context);this.mContext = context;initView();}private void initView() {//为满足多分辨率的需求，通过屏幕的density来计算maxOverScrollY的具体DisplayMetrics metrics = mContext.getResources().getDisplayMetrics();float density = metrics.density;mMaxOverDistance = (int) (density * mMaxOverDistance);}@Overrideprotected boolean overScrollBy(int deltaX, int deltaY,int scrollX, int scrollY,int scrollRangeX, int scrollRangeY,int maxOverScrollX, int maxOverScrollY,boolean isTouchEvent) {return super.overScrollBy(deltaX, deltaY,scrollX, scrollY,scrollRangeX, scrollRangeY,maxOverScrollX, mMaxOverDistance,isTouchEvent);}
}
FlexibleListViewTest.java
package sunny.example.ahfourflexiblelistviewtest;
//具有弹性的ListView
import android.app.Activity;
import android.os.Bundle;
import android.widget.ArrayAdapter;public class FlexibleListViewTest extends Activity {private FlexibleListView mFlexibleListView;private String[] data = new String[30];@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.flexible);for (int i = 0; i < 30; i++) {data[i] = "" + i;}mFlexibleListView = (FlexibleListView) findViewById(R.id.flexible_listview);mFlexibleListView.setAdapter(new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1,data));}
}
flexible.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"android:layout_width="match_parent"android:layout_height="match_parent"android:orientation="vertical"><sunny.example.ahfourflexiblelistviewtest.FlexibleListViewandroid:id="@+id/flexible_listview"android:layout_width="match_parent"android:layout_height="match_parent" />
</LinearLayout>
)
