关于Android沉浸式状态栏的一个做法

话不多说，直接上代码

首先在build.gradle文件中引入库：

compile 'com.readystatesoftware.systembartint:systembartint:1.0.3'

这是布局文件：

<?xml version="1.0" encoding="utf-8"?><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"    android:orientation="vertical">         <com.title.MyScrollView            android:id="@+id/scrollView"            android:layout_width="match_parent"            android:layout_height="match_parent">            <LinearLayout                android:layout_width="match_parent"                android:layout_height="0dp"                android:orientation="vertical">                <ImageView                    android:id="@+id/image"                    android:layout_width="match_parent"                    android:layout_height="300dp"                    android:orientation="vertical"                    android:background="@mipmap/qqq"/>                <LinearLayout                    android:layout_width="match_parent"                    android:layout_height="300dp"                    android:orientation="vertical"                    android:background="#999999"/>                <LinearLayout                    android:layout_width="match_parent"                    android:layout_height="300dp"                    android:orientation="vertical"                    android:background="#FF0000"/>                <LinearLayout                    android:layout_width="match_parent"                    android:layout_height="300dp"                    android:orientation="vertical"                    android:background="#FF8000"/>            </LinearLayout>        </com.title.MyScrollView>    <RelativeLayout        android:id="@+id/rl2"        android:layout_width="match_parent"        android:layout_height="wrap_content">        <RelativeLayout            android:id="@+id/rl"            android:layout_width="match_parent"            android:layout_height="wrap_content">            <TextView                android:layout_width="wrap_content"                android:layout_height="wrap_content"                android:text="返回"                android:textSize="18sp"                android:textColor="#FFFFFF"                android:layout_centerVertical="true"                android:layout_marginLeft="10dp"/>            <TextView                android:layout_width="wrap_content"                android:layout_height="wrap_content"                android:text="主界面"                android:textSize="18sp"                android:textColor="#FFFFFF"                android:layout_centerInParent="true" />            <TextView                android:layout_width="wrap_content"                android:layout_height="wrap_content"                android:text="添加"                android:textSize="18sp"                android:textColor="#FFFFFF"                android:layout_alignParentRight="true"                android:layout_centerVertical="true"                android:layout_marginRight="10dp"/>        </RelativeLayout>    </RelativeLayout></RelativeLayout>

MyScrollView是重新写的一个ScrollView，其实也就是给它添加一个滑动事件

public class MyScrollView extends ScrollView{    public interface ScrollViewListener {        void onScrollChanged(MyScrollView scrollView, int x, int y,                             int oldx, int oldy);    }        private ScrollViewListener scrollViewListener = null;    public MyScrollView(Context context) {        super(context);    }    public MyScrollView(Context context, AttributeSet attrs,                                int defStyle) {        super(context, attrs, defStyle);    }    public MyScrollView(Context context, AttributeSet attrs) {        super(context, attrs);    }    public void setScrollViewListener(ScrollViewListener scrollViewListener) {        this.scrollViewListener = scrollViewListener;    }    @Override    protected void onScrollChanged(int x, int y, int oldx, int oldy) {        super.onScrollChanged(x, y, oldx, oldy);        if (scrollViewListener != null) {            scrollViewListener.onScrollChanged(this, x, y, oldx, oldy);        }    }}

接下来就是如何实现沉浸式了。4.4以上版本才可以实现沉浸式，分为4.4到5.0和5.0以上两个版本。

private void setView(){    //定义一个LayoutParams    RelativeLayout.LayoutParams layoutParams = new RelativeLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);    layoutParams.height = 100;    if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT){        //设置导航栏总体高度        RelativeLayout.LayoutParams layout = new RelativeLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);        layout.height = 100 + getStatusBarHeight();        rl2.setLayoutParams(layout);        layoutParams.setMargins(0, getStatusBarHeight(), 0, 0);        Window window = getWindow();        ViewGroup mContentView = (ViewGroup) findViewById(Window.ID_ANDROID_CONTENT);        //Android5.0以上        if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP){            //设置透明状态栏,这样才能让 ContentView 向上            window.addFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);            //需要设置这个 flag 才能调用 setStatusBarColor 来设置状态栏颜色            window.addFlags(WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS);            //设置状态栏颜色            window.setStatusBarColor(Color.TRANSPARENT);            View mChildView = mContentView.getChildAt(0);            if (mChildView != null) {                //注意不是设置 ContentView 的 FitsSystemWindows, 而是设置 ContentView 的第一个子 View . 使其不为系统 View 预留空间.                ViewCompat.setFitsSystemWindows(mChildView, false);            }        }else{            //Android4.4到5.0之间            //首先使 ChildView 不预留空间            View mChildView = mContentView.getChildAt(0);            if (mChildView != null) {                ViewCompat.setFitsSystemWindows(mChildView, false);            }            int statusBarHeight = getStatusBarHeight();            //需要设置这个 flag 才能设置状态栏            window.addFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);            //避免多次调用该方法时,多次移除了 View            if (mChildView != null && mChildView.getLayoutParams() != null && mChildView.getLayoutParams().height == statusBarHeight) {                //移除假的 View.                mContentView.removeView(mChildView);                mChildView = mContentView.getChildAt(0);            }            if (mChildView != null) {                FrameLayout.LayoutParams lp = (FrameLayout.LayoutParams) mChildView.getLayoutParams();                //清除 ChildView 的 marginTop 属性                if (lp != null && lp.topMargin >= statusBarHeight) {                    lp.topMargin -= statusBarHeight;                    mChildView.setLayoutParams(lp);                }            }        }    }    rl.setLayoutParams(layoutParams);}/** * 获取状态栏高度 * @return */private int getStatusBarHeight() {    int result = 0;    int resourceId = getResources().getIdentifier("status_bar_height", "dimen", "android");    if (resourceId > 0) {        result = getResources().getDimensionPixelSize(resourceId);    }    return result;}private void initListeners() {    // 获取顶部图片高度后，设置滚动监听    ViewTreeObserver vto = img.getViewTreeObserver();    vto.addOnGlobalLayoutListener(new OnGlobalLayoutListener() {        @Override        public void onGlobalLayout() {            img.getViewTreeObserver().removeGlobalOnLayoutListener(                    this);    height = img.getHeight();    scrollView.setScrollViewListener(MainActivity.this);        }    });}//scrollview的滚动监听@Overridepublic void onScrollChanged(MyScrollView scrollView, int x, int y, int oldx, int oldy) {    if (y <= 0) {        rl2.setBackgroundColor(Color.argb((int) 0, 51, 143, 255));    } else if (y > 0 && y <= height) {        float scale = (float) y / height;        float alpha = (255 * scale);        rl2.setBackgroundColor(Color.argb((int) alpha, 51, 143, 255));    } else {        rl2.setBackgroundColor(Color.argb((int) 255, 51, 143, 255));    }}

代码就是这些了。虽然实现了效果，不过有个局限性问题，就是布局文件的根元素必须是<RelativeLayout></RelativeLayout>。