首先：上效果图，一共是两张，第一张是最开始的样子，第二张是所需要达到的效果。
先讲解一下需求与功能点。ScollView里面的一个layout，当它往上滑动到屏幕顶端时自动悬停在顶端，当往下滑动时会跟着Scrollview一起滑动。
做法：写了一个与悬停一模一样的layout先隐藏在scrollview后面，在scrollview滑动时监听里面layout的高度，当它的高度为屏幕的顶端了时，隐藏的layout显示，反之显示。其实是很简单的。
首先上main.xml：
<?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"
android:orientation="vertical" >
<com.stay.test.StayScrollView
android:id="@+id/stayScrollView"
android:layout_width="fill_parent"
android:layout_height="fill_parent" >
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<ImageView
android:layout_width="fill_parent"
android:layout_height="203dp"
android:src="@drawable/stay" />
<LinearLayout
android:id="@+id/stayScrollLayout"
android:layout_width="fill_parent"
android:layout_height="30dp"
android:background="@android:color/darker_gray"
android:gravity="center" >
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Stay"
android:textColor="@android:color/white" />
</LinearLayout>
<TextView
android:layout_width="fill_parent"
android:layout_height="800dp"
android:background="@android:color/black"
android:text="自己写点内容吧。。。"
android:textColor="@android:color/white" />
</LinearLayout>
</com.stay.test.StayScrollView>
<LinearLayout
android:id="@+id/stayLayout"
android:layout_width="fill_parent"
android:layout_height="30dp"
android:background="@android:color/darker_gray"
android:gravity="center"
android:visibility="gone" >
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Stay"
android:textColor="@android:color/white" />
</LinearLayout>
</RelativeLayout>
自定义ScrollView（StayScrollView），主要是为了监听滑动事件。
package com.stay.test;import android.content.Context;
import android.util.AttributeSet;
import android.widget.ScrollView;public class StayScrollView extends ScrollView {OnScrollLisener mListener;public StayScrollView(Context context) {super(context);}public StayScrollView(Context context, AttributeSet attrs) {super(context, attrs);}public StayScrollView(Context context, AttributeSet attrs, int defStyle) {super(context, attrs, defStyle);}@Overrideprotected void onScrollChanged(int l, int t, int oldl, int oldt) {if (null != mListener) {mListener.onScroll(l, t, oldl, oldt);}super.onScrollChanged(l, t, oldl, oldt);}public void setOnScrollListener(OnScrollLisener listener) {if (null != listener) {mListener = listener;}}public abstract interface OnScrollLisener {public abstract void onScroll(int l, int t, int oldl, int oldt);}
}
然后再是MainActivity:
package com.stay.test;import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.Window;
import android.widget.LinearLayout;import com.stay.test.StayScrollView.OnScrollLisener;public class MainActivity extends Activity {private StayScrollView stayScroll;private LinearLayout stayLayout;private LinearLayout stayScrollLayout;private boolean flag = true;private int statusBarHeight = 0;private int topicBarHeight = 0;@Overridepublic void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.main);init();stayScroll.setOnScrollListener(new OnScrollLisener() {@Overridepublic void onScroll(int l, int t, int oldl, int oldt) {if(flag){flag = false;
// statusBarHeight = DeviceUtil.getStatusBarHeight();topicBarHeight = getWindow().findViewById(Window.ID_ANDROID_CONTENT).getTop();}fun();}});}private void init() {stayScroll = (StayScrollView) findViewById(R.id.stayScrollView);stayScroll.setOverScrollMode(View.OVER_SCROLL_NEVER);stayLayout = (LinearLayout) findViewById(R.id.stayLayout);stayScrollLayout = (LinearLayout) findViewById(R.id.stayScrollLayout);}private void fun() {int[] location = new int[2];stayScrollLayout.getLocationOnScreen(location);int y = location[1]; // stayScrollLayout的高度int height = statusBarHeight+topicBarHeight;if (height > y) {if(stayLayout.getVisibility() == View.GONE){stayLayout.setVisibility(View.VISIBLE);}} else {if(stayLayout.getVisibility() == View.VISIBLE){stayLayout.setVisibility(View.GONE);}}}
}
OK，class dismiss。
资源，我上传了n次，但csdn....
好了，不说也罢~
但是这个fun()方法的处理有点问题，如果在一些差一点的手机上会卡，因为它一直在计算其中一个控件的位置。暂时没找到好的解决方法。如果有再更新，也可以指教！谢谢