Android 自定义ScrollView实现滑动时状态栏变色。

先看效果：

首先自定义ScrollView ,实现监听。

public class DiscolourScrollView extends ScrollView {
    private ScrollViewListener scrollViewListener;

    public DiscolourScrollView(Context context) {
        super(context);
    }

    public DiscolourScrollView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public DiscolourScrollView(Context context, AttributeSet attrs,int defStyle) {
        super(context, attrs, defStyle);
    }
    //接口回调
    public interface ScrollViewListener {

        void onScrollChanged(DiscolourScrollView scrollView, int x, int y,int oldx, int oldy);

    }
    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);
        }
    }
}

布局的实现：

<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
>

    <包名.DiscolourScrollView
        android:id="@+id/scrollview"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:scrollbars="none">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical">

            <ImageView
                android:id="@+id/imageview"
                android:layout_width="match_parent"
                android:layout_height="200dp"
                android:background="@mipmap/ic_launcher"/>
            <ImageView
                android:layout_width="match_parent"
                android:layout_height="200dp"
                android:background="@mipmap/ic_launcher"/>

            <ImageView
                android:layout_width="match_parent"
                android:layout_height="200dp"
                android:background="@mipmap/ic_launcher"/>
            <ImageView
                android:layout_width="match_parent"
                android:layout_height="200dp"
                android:background="@mipmap/ic_launcher"/>
            <ImageView
                android:layout_width="match_parent"
                android:layout_height="200dp"
                android:background="@mipmap/ic_launcher"/>
        LinearLayout>
    包名.DiscolourScrollView>
    <android.support.v7.widget.Toolbar
        xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@+id/textview"
        android:layout_width="match_parent"
        android:layout_height="72dp"
        android:fitsSystemWindows="true" //关键 要加上
        android:background="#00000000"
    >
        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="horizontal"
        >
            <ImageView
                android:id="@+id/tocamera_fg"
                android:layout_width="wrap_content"
                android:layout_height="match_parent"
                android:layout_weight="1"
                android:src="@mipmap/ic_launcher"
            />
            <TextView
                android:id="@+id/top_title"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_weight="9"
                android:gravity="center"
                android:text="标题"
                android:textColor="#fafaf3"
                android:textSize="18sp"/>
            <TextView
                android:id="@+id/query_btn"
                android:layout_width="wrap_content"
                android:layout_height="match_parent"
                android:layout_gravity="left"
                android:layout_weight="1"
                android:text="保存"
                android:textColor="#FFFFFF"
                android:textSize="15sp"
            />
        LinearLayout>
    android.support.v7.widget.Toolbar>
RelativeLayout>

让状态栏透明化

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
            Window window = getWindow();
            window.clearFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
            window.getDecorView().setSystemUiVisibility(View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN | View.SYSTEM_UI_FLAG_LAYOUT_STABLE);
            window.addFlags(WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS);
            window.setStatusBarColor(Color.TRANSPARENT);
        }

Activity中的实现

public class Main2Activity extends AppCompatActivity implements DiscolourScrollView.ScrollViewListener {

    private DiscolourScrollView scrollView;


    private ImageView imageView;

    private Toolbar textView;

    private int imageHeight;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
            Window window = getWindow();
            window.clearFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
            window.getDecorView().setSystemUiVisibility(View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN | View.SYSTEM_UI_FLAG_LAYOUT_STABLE);
            window.addFlags(WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS);
            window.setStatusBarColor(Color.TRANSPARENT);
        }
        setContentView(R.layout.activity_main2);
        scrollView = (DiscolourScrollView) findViewById(R.id.scrollview);
        imageView = (ImageView) findViewById(R.id.imageview);
        textView = (Toolbar) findViewById(R.id.textview);
        initListeners();

    }


    private void initListeners() {
        // 获取顶部图片高度后，设置滚动监听
        ViewTreeObserver vto = imageView.getViewTreeObserver();
        vto.addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
            @Override
            public void onGlobalLayout() {
                imageView.getViewTreeObserver().removeGlobalOnLayoutListener(
                        this);
                imageHeight = imageView.getHeight();

                scrollView.setScrollViewListener(Main2Activity.this);
            }
        });
    }

    @Override
    public void onScrollChanged(DiscolourScrollView scrollView, int x, int y,
                                int oldx, int oldy) {
        // TODO Auto-generated method stub
        // Log.i("TAG", "y--->" + y + "    height-->" + height);
        if (y <= 0) {
            textView.setBackgroundColor(Color.argb((int) 0, 227, 29, 26));//这里设置颜色
        } else if (y > 0 && y <= imageHeight) {
            float scale = (float) y / imageHeight;
            float alpha = (255 * scale);
            // 只是layout背景透明
            textView.setBackgroundColor(Color.argb((int) alpha, 227, 29, 26));
        } else {
            textView.setBackgroundColor(Color.argb((int) 255, 227, 29, 26));
        }
    }
}