沉浸式

我对沉浸式的理解就是状态栏和导航栏变为透明
把背景图片和标题栏显示出来
比如

image.png

通过theme实现方式

//valuse
<style name="TranslucentTheme" parent="AppTheme">
</style>

// values-v19。v19 开始有 android:windowTranslucentStatus 这个属性
<style name="TranslucentTheme" parent="Theme.AppCompat.Light.NoActionBar">
        <item name="android:windowTranslucentStatus">true</item>
        <item name="android:windowTranslucentNavigation">true</item>
</style>

// values-v21。5.0 以上提供了 setStatusBarColor()  方法设置状态栏颜色。
<style name="TranslucentTheme" parent="Theme.AppCompat.Light.NoActionBar">
    <item name="android:windowTranslucentStatus">false</item>
    <item name="android:windowTranslucentNavigation">true</item>
    <!--Android 5.x开始需要把颜色设置透明，否则导航栏会呈现系统默认的浅灰色-->
    <item name="android:statusBarColor">@android:color/transparent</item>
</style>

通过代码设置

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
    int flagTranslucentStatus = WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS;
    int flagTranslucentNavigation = WindowManager.LayoutParams.FLAG_TRANSLUCENT_NAVIGATION;
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
        Window window = getWindow();
        WindowManager.LayoutParams attributes = window.getAttributes();
        attributes.flags |= flagTranslucentNavigation;
        window.setAttributes(attributes);
        getWindow().setStatusBarColor(Color.TRANSPARENT);
    } else {
        Window window = getWindow();
        WindowManager.LayoutParams attributes = window.getAttributes();
        attributes.flags |= flagTranslucentStatus | flagTranslucentNavigation;
        window.setAttributes(attributes);
    }
}

/**
 * 通过设置全屏，设置状态栏透明
 *
 * @param activity
 */
private void fullScreen(Activity activity) {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
            //5.x开始需要把颜色设置透明，否则导航栏会呈现系统默认的浅灰色
            Window window = activity.getWindow();
            View decorView = window.getDecorView();
            //两个 flag 要结合使用，表示让应用的主体内容占用系统状态栏的空间
            int option = View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
                    | View.SYSTEM_UI_FLAG_LAYOUT_STABLE;
            decorView.setSystemUiVisibility(option);
            window.addFlags(WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS);
            window.setStatusBarColor(Color.TRANSPARENT);
            //导航栏颜色也可以正常设置
//                window.setNavigationBarColor(Color.TRANSPARENT);
        } else {
            Window window = activity.getWindow();
            WindowManager.LayoutParams attributes = window.getAttributes();
            int flagTranslucentStatus = WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS;
            int flagTranslucentNavigation = WindowManager.LayoutParams.FLAG_TRANSLUCENT_NAVIGATION;
            attributes.flags |= flagTranslucentStatus;
//                attributes.flags |= flagTranslucentNavigation;
            window.setAttributes(attributes);
        }
    }
}

图一发现标题栏被顶上去了解决方法有三种

法一：设置 fitsSystemWindows 属性
法二：布局里添加占位状态栏
法三：代码中设置 paddingTop 并添加占位状态栏