具体代码：
ublic class MainActivity extends Activity implements OnScrollListener{
/**
* 自定义的MyScrollView
*/
private MyScrollView myScrollView;
/**
* 在MyScrollView里面的购买布局
*/
private LinearLayout mBuyLayout;
/**
* 位于顶部的购买布局
*/
private LinearLayout mTopBuyLayout;
@SuppressWarnings("deprecation")
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
myScrollView = (MyScrollView) findViewById(R.id.scrollView);
mBuyLayout = (LinearLayout) findViewById(R.id.buy);
mTopBuyLayout = (LinearLayout) findViewById(R.id.top_buy_layout);
myScrollView.setOnScrollListener(this);
//当布局的状态或者控件的可见性发生改变回调的接口
findViewById(R.id.parent_layout).getViewTreeObserver().addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
@Override
public void onGlobalLayout() {
//这一步很重要，使得上面的购买布局和下面的购买布局重合
onScroll(myScrollView.getScrollY());
System.out.println(myScrollView.getScrollY());
}
});
}
@Override
public void onScroll(int scrollY) {
int mBuyLayout2ParentTop = Math.max(scrollY, mBuyLayout.getTop());
mTopBuyLayout.layout(0, mBuyLayout2ParentTop, mTopBuyLayout.getWidth(), mBuyLayout2ParentTop + mTopBuyLayout.getHeight());
}
}
自定义的控件：
public class MyScrollView extends ScrollView {
private OnScrollListener onScrollListener;
public MyScrollView(Context context) {
this(context, null);
}
public MyScrollView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public MyScrollView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
/**
* 设置滚动接口
* @param onScrollListener
*/
public void setOnScrollListener(OnScrollListener onScrollListener) {
this.onScrollListener = onScrollListener;
}
@Override
protected void onScrollChanged(int l, int t, int oldl, int oldt) {
super.onScrollChanged(l, t, oldl, oldt);
if(onScrollListener != null){
onScrollListener.onScroll(t);
}
}
/**
*
* 滚动的回调接口
*
* @author xiaanming
*
*/
public interface OnScrollListener{
/**
* 回调方法， 返回MyScrollView滑动的Y方向距离
* @param scrollY
* 、
*/
public void onScroll(int scrollY);
}
}
activity的布局：
activity_main:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/parent_layout"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<ImageView
android:id="@+id/imageView1"
android:layout_width="match_parent"
android:layout_height="45dip"
android:scaleType="centerCrop"
android:src="@drawable/navigation_bar" />
<com.example.meituandemo.MyScrollView
android:id="@+id/scrollView"
android:layout_width="fill_parent"
android:layout_height="fill_parent" >
<FrameLayout
android:layout_width="match_parent"
android:layout_height="wrap_content" >
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical" >
<ImageView
android:id="@+id/iamge"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@drawable/pic"
android:scaleType="centerCrop" />
<include
android:id="@+id/buy"
layout="@layout/buy_layout" />
<ImageView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@drawable/one"
android:scaleType="centerCrop" />
<ImageView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@drawable/one"
android:scaleType="centerCrop" />
<ImageView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@drawable/one"
android:scaleType="centerCrop" />
</LinearLayout>
<include
android:id="@+id/top_buy_layout"
layout="@layout/buy_layout" />
</FrameLayout>
</com.example.meituandemo.MyScrollView>
</LinearLayout>
buy_layout布局：
<?xml version="1.0" encoding="UTF-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="wrap_content" >
<ImageView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:background="@drawable/buy" />
</LinearLayout>