Android StatusBar 的顏色

 Android 5.0以後支持statusbar 更換顏色，6.0以後支持夜間模式

  /**
     * 設置狀態欄的顏色
     */
    protected void setStatusBarColor(int color, boolean lightTheme) {
        if (lightTheme) {
            if (Build.VERSION.SDK_INT > Build.VERSION_CODES.LOLLIPOP &&
                    Build.VERSION.SDK_INT < Build.VERSION_CODES.M &&
                    !BaseDeviceUtils.isXiaoMi()) {
                StatusBarUtil.setStatusBarColor(this, color, 40);
            } else {
                StatusBarUtil.setStatusBarColor(this, color, 0);
                setStatusBarTheme(false);
            }
        } else {
            StatusBarUtil.setStatusBarColor(this, color, 0);
            setStatusBarTheme(true);
        }
    }

    public void setStatusBarTheme(boolean darkMode) {
        //原生6.0以上有API支持黑條狀態欄圖標，但是國產各ROM經過定製，
        // 有的需要特定的設置才能實現
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            View decorView = getWindow().getDecorView();
            int systemuiVisibility = decorView.getSystemUiVisibility();
            if (darkMode) {
                decorView.setSystemUiVisibility(systemuiVisibility & ~View.SYSTEM_UI_FLAG_LIGHT_STATUS_BAR);
            } else {
                decorView.setSystemUiVisibility(systemuiVisibility | View.SYSTEM_UI_FLAG_LIGHT_STATUS_BAR);
            }
        }
        this.setupStatusBarForOtherSystem(darkMode);
    }

    protected int getCustomStatusBarColor() {
        if (isLightTheme()) {
            return getResources().getColor(R.color.status_bar_color_light);
        }
        return getResources().getColor(R.color.status_bar_color_dark);
    }

    protected void setupStatusBarForOtherSystem(boolean dark) {
        StatusBarUtil.setupStatusBarForOtherSystem(this, !dark);
    }

public class StatusBarUtil {

    /**
     * 計算狀態欄顏色
     *
     * @param color color值
     * @param alpha alpha值
     * @return 最終的狀態欄顏色
     */
    private static int calculateStatusColor(@ColorInt int color, int alpha) {
        if (alpha == 0) {
            return color;
        }
        float a = 1 - alpha / 255f;
        int red = color >> 16 & 0xff;
        int green = color >> 8 & 0xff;
        int blue = color & 0xff;
        red = (int) (red * a + 0.5);
        green = (int) (green * a + 0.5);
        blue = (int) (blue * a + 0.5);
        return 0xff << 24 | red << 16 | green << 8 | blue;
    }

    /**
     * 設置狀態欄顏色
     *
     * @param activity       需要設置的activity
     * @param color          狀態欄顏色值
     * @param statusBarAlpha 狀態欄透明度
     */

    public static void setStatusBarColor(Activity activity, @ColorInt int color, @IntRange(from = 0, to = 255) int statusBarAlpha) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
            activity.getWindow().addFlags(WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS);
            activity.getWindow().clearFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
            activity.getWindow().setStatusBarColor(calculateStatusColor(color, statusBarAlpha));
        }
    }


    public static boolean setupStatusBarForOtherSystem(Activity activity, boolean setDarkMode) {
        if (BaseDeviceUtils.isXiaoMi()) {
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
                Class<? extends Window> windowClass = activity.getWindow().getClass();
                try {
                    Class<?> layoutParams = Class.forName("android.view.MiuiWindowManager.LayoutParams");
                    int darkmode = layoutParams.getField("EXTRA_FLAG_STATUS_BAR_DARK_MODE").getInt(layoutParams);
                    Method setExtraFlags = windowClass.getMethod("setExtraFlags", Integer.TYPE, Integer.TYPE);
                    int mode = setDarkMode ? darkmode : 0;
                    setExtraFlags.invoke(activity.getWindow(),mode,darkmode);
                } catch (ClassNotFoundException | NoSuchFieldException | IllegalAccessException | NoSuchMethodException | InvocationTargetException e) {
                    e.printStackTrace();
                }
            }
        }
        return false;
    }

}

 public static boolean isXiaoMi() {
        return Build.MANUFACTURER.equalsIgnoreCase("xiaomi");
    }

不同的廠商可能實現不同，實測魅族可以。

最好封裝到BaseActivity 裏面，在初始化（setContentView 之前）的時候去改變statusbar 的顏色或者模式。

Activity 的setContentView 會先創建 DecorView 在創建DecorView 的時候會 根據Theme 去加載不同的ViewParent（RootView）(所以Theme在setContentView 之後調用無效)，然後add進DecorView.一般rootview 包含了 Title 和content 兩部分，setContentView就是將

傳進來的view 添加到content。