89、Android EditText 悬浮停靠

package com.willen.topFloatDemo;

import android.content.Context;
import android.os.Handler;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.widget.ScrollView;

/*
* 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，
* 我们很自然的想到在onTouchEvent()方法中实现对滚动Y轴进行监听
* ScrollView的滚动Y值进行监听
*/
public class MyScrollView extends ScrollView {

private OnScrollListener onScrollListener;
/**
* 主要是用在用户手指离开MyScrollView，MyScrollView
* 还在继续滑动，我们用来保存Y的距离，然后做比较
*/
private int lastScrollY;

public MyScrollView(Context context) {
super(context, null);
}
public MyScrollView(Context context, AttributeSet attrs) {
super(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;
}
/**
* 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
*/
private Handler handler = new Handler() {
public void handleMessage(android.os.Message msg) {
int scrollY = MyScrollView.this.getScrollY();
//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
if(lastScrollY != scrollY){
lastScrollY = scrollY;
handler.sendMessageDelayed(handler.obtainMessage(), 5);
}
if(onScrollListener != null){
onScrollListener.onScroll(scrollY);
}
};
};

/**
* 重写onTouchEvent， 当用户的手在MyScrollView上面的时候，
* 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，
* 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
* MyScrollView滑动的距离
*/
@Override
public boolean onTouchEvent(MotionEvent ev) {
if(onScrollListener != null){
onScrollListener.onScroll(lastScrollY = this.getScrollY());
}
switch(ev.getAction()){
case MotionEvent.ACTION_UP:
handler.sendMessageDelayed(handler.obtainMessage(), 20);
break;
}
return super.onTouchEvent(ev);
}

/**
* 滚动的回调接口
*/
public interface OnScrollListener{
// 回调方法， 返回MyScrollView滑动的Y方向距离
public void onScroll(int scrollY);
}
}

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�
}
}

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@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);
}
}
}
}