title.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="@+id/top_bg"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@color/white"
android:orientation="vertical">
<View
android:id="@+id/viewTop"
android:layout_width="match_parent"
android:layout_height="25dp" />
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="45dp">
<ImageView
android:id="@+id/toolbar_iv_back"
android:layout_width="45dp"
android:layout_height="match_parent"
android:layout_gravity="center"
android:padding="14dp"
android:src="@drawable/img_back" />
<TextView
android:id="@+id/toolbar_tv_title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:layout_marginLeft="45dp"
android:layout_marginRight="60dp"
android:ellipsize="end"
android:gravity="center"
android:lines="1"
android:text="我是标题"
android:textSize="17sp"
/>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_alignParentRight="true"
android:layout_centerVertical="true">
<TextView
android:id="@+id/toolbar_tv_menu"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:gravity="center"
android:lines="1"
android:paddingLeft="10dp"
android:paddingRight="10dp"
android:textSize="14sp"
/>
<ImageView
android:id="@+id/toolbar_iv_menu"
android:layout_width="45dp"
android:layout_height="match_parent"
android:padding="14dp"
android:visibility="gone" />
</LinearLayout>
</RelativeLayout>
<View
android:id="@+id/view_line"
android:layout_width="match_parent"
android:layout_height="0.5dp"
android:background="@color/background"
/>
</LinearLayout>
activity_main.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent">
<com.cy.myapplication.MyScrollView
android:id="@+id/scroller"
android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="2000dp"
android:background="@color/colorAccent" />
</LinearLayout>
</com.cy.myapplication.MyScrollView>
<include
layout="@layout/title" />
</RelativeLayout>
MyScrollView 自定义滚动View
package com.cy.myapplication;
import android.content.Context;
import android.os.Build;
import android.os.Handler;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.widget.ScrollView;
import androidx.annotation.RequiresApi;
/**
* Created by ShinnyYang on 2020/8/18.
*/
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);
}
public MyScrollView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public MyScrollView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
}
@RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
public MyScrollView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
super(context, attrs, defStyleAttr, defStyleRes);
}
/**
* 设置滚动接口
* @param onScrollListener
*/
public void setScrolListener(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();
if(onScrollListener != null){
onScrollListener.onScroll(scrollY);
}
//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);
}
}
};
/**
* 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20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());
}
if(ev.getAction() == MotionEvent.ACTION_UP){
handler.sendMessageDelayed(handler.obtainMessage(), 20);
}
return super.onTouchEvent(ev);
}
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);
}
}
Main里面实现
private LinearLayout top_bg;
private MyScrollView scroller;
private void initView() {
top_bg = (LinearLayout) findViewById(R.id.top_bg);
scroller = (MyScrollView) findViewById(R.id.scroller);
top_bg.getBackground().setAlpha(0);
scroller.setScrolListener(this);
}
@Override
public void onScroll(int scrollY) {
if (scrollY < 100) {
top_bg.getBackground().setAlpha(0);
} else if (scrollY >= 100 && scrollY < 860) {
top_bg.getBackground().setAlpha((scrollY - 100) / 3);
} else {
top_bg.getBackground().setAlpha(255);
}
}
<color name="white">#ffffff</color>
<color name="black">#000000</color>
<color name="background">#f6f6f6</color>
网友评论