1 package com.willen.topFloatDemo;
2
3 import android.content.Context;
4 import android.os.Handler;
5 import android.util.AttributeSet;
6 import android.view.MotionEvent;
7 import android.widget.ScrollView;
8
9 /*
10 * ScrollView并没有实现滚动监听，所以我们必须自行实现对ScrollView的监听，
11 * 我们很自然的想到在onTouchEvent()方法中实现对滚动Y轴进行监听
12 * ScrollView的滚动Y值进行监听
13 */
14 public class MyScrollView extends ScrollView {
15
16 private OnScrollListener onScrollListener;
17 /**
18 * 主要是用在用户手指离开MyScrollView，MyScrollView
19 * 还在继续滑动，我们用来保存Y的距离，然后做比较
20 */
21 private int lastScrollY;
22
23 public MyScrollView(Context context) {
24 super(context, null);
25 }
26 public MyScrollView(Context context, AttributeSet attrs) {
27 super(context, attrs, 0);
28 }
29 public MyScrollView(Context context, AttributeSet attrs, int defStyle) {
30 super(context, attrs, defStyle);
31 }
32
33 /**
34 * 设置滚动接口
35 * @param onScrollListener
36 */
37 public void setOnScrollListener(OnScrollListener onScrollListener){
38 this.onScrollListener = onScrollListener;
39 }
40 /**
41 * 用于用户手指离开MyScrollView的时候获取MyScrollView滚动的Y距离，然后回调给onScroll方法中
42 */
43 private Handler handler = new Handler() {
44 public void handleMessage(android.os.Message msg) {
45 int scrollY = MyScrollView.this.getScrollY();
46 //此时的距离和记录下的距离不相等，在隔5毫秒给handler发送消息
47 if(lastScrollY != scrollY){
48 lastScrollY = scrollY;
49 handler.sendMessageDelayed(handler.obtainMessage(), 5);
50 }
51 if(onScrollListener != null){
52 onScrollListener.onScroll(scrollY);
53 }
54 };
55 };
56
57 /**
58 * 重写onTouchEvent， 当用户的手在MyScrollView上面的时候，
59 * 直接将MyScrollView滑动的Y方向距离回调给onScroll方法中，当用户抬起手的时候，
60 * MyScrollView可能还在滑动，所以当用户抬起手我们隔5毫秒给handler发送消息，在handler处理
61 * MyScrollView滑动的距离
62 */
63 @Override
64 public boolean onTouchEvent(MotionEvent ev) {
65 if(onScrollListener != null){
66 onScrollListener.onScroll(lastScrollY = this.getScrollY());
67 }
68 switch(ev.getAction()){
69 case MotionEvent.ACTION_UP:
70 handler.sendMessageDelayed(handler.obtainMessage(), 20);
71 break;
72 }
73 return super.onTouchEvent(ev);
74 }
75
76 /**
77 * 滚动的回调接口
78 */
79 public interface OnScrollListener{
80 // 回调方法， 返回MyScrollView滑动的Y方向距离
81 public void onScroll(int scrollY);
82 }
83 }
package com.willen.topFloatDemo;
import android.app.Activity;
import android.os.Bundle;
import android.widget.EditText;
import android.widget.LinearLayout;
import android.widget.RelativeLayout;
import com.willen.topFloatDemo.MyScrollView.OnScrollListener;
public class MainActivity extends Activity implements OnScrollListener{
private EditText search_edit;
private MyScrollView myScrollView;
private int searchLayoutTop;
LinearLayout search01,search02;
RelativeLayout rlayout;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
init();
}
private void init() {
search_edit = (EditText)findViewById(R.id.search_edit);
myScrollView = (MyScrollView)findViewById(R.id.myScrollView);
search01 = (LinearLayout)findViewById(R.id.search01);
search02 = (LinearLayout)findViewById(R.id.search02);
rlayout = (RelativeLayout)findViewById(R.id.rlayout);
myScrollView.setOnScrollListener(this);
}
@Override
public void onWindowFocusChanged(boolean hasFocus) {
super.onWindowFocusChanged(hasFocus);
if(hasFocus){
searchLayoutTop = rlayout.getBottom();//鑾峰彇searchLayout鐨勯《閮ㄤ綅缃�
}
}
//鐩戝惉婊氬姩Y鍊煎彉鍖栵紝閫氳繃addView鍜宺emoveView鏉ュ疄鐜版偓鍋滄晥鏋�
@Override
public void onScroll(int scrollY) {
if(scrollY >= searchLayoutTop){
if (search_edit.getParent()!=search01) {
search02.removeView(search_edit);
search01.addView(search_edit);
}
}else{
if (search_edit.getParent()!=search02) {
search01.removeView(search_edit);
search02.addView(search_edit);
}
}
}
}