android：一行代码实现沉浸式布局效果

• 先看效果

效果一：

20170208160944467.png

效果二：

20170208161011359.png

• 首先要引入statusbaruitl库

```
 compile 'com.jaeger.statusbaruitl:library:1.3.5'
```

• 在Activity中一行代码实现：

    //目的是让状态栏全透明
        StatusBarUtil.setTransparent(MainActivity.this);

这样当前Activity就实现了沉浸式布局效果。

• 那我们来看看StatusBarUtil的内容吧，注释写的相当详细

package com.jaeger.library;

import android.annotation.TargetApi;
import android.app.Activity;
import android.content.Context;
import android.graphics.Color;
import android.os.Build;
import android.support.v4.widget.DrawerLayout;
import android.view.ViewGroup;
import android.view.WindowManager;
import android.widget.LinearLayout;

/**
 * Created by Jaeger on 16/2/14.
 *
 * Email: [email protected]
 * GitHub: https://github.com/laobie
 */
public class StatusBarUtil {

    public static final int DEFAULT_STATUS_BAR_ALPHA = 112;

    /**
     * 设置状态栏颜色
     *
     * @param activity 需要设置的 activity
     * @param color    状态栏颜色值
     */
    public static void setColor(Activity activity, int color) {
        setColor(activity, color, DEFAULT_STATUS_BAR_ALPHA);
    }

    /**
     * 设置状态栏颜色
     *
     * @param activity       需要设置的activity
     * @param color          状态栏颜色值
     * @param statusBarAlpha 状态栏透明度
     */
    public static void setColor(Activity activity, int color, 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));
        } else if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
            activity.getWindow().addFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
            ViewGroup decorView = (ViewGroup) activity.getWindow().getDecorView();
            int count = decorView.getChildCount();
            if (count > 0 && decorView.getChildAt(count - 1) instanceof StatusBarView) {
                decorView.getChildAt(count - 1).setBackgroundColor(calculateStatusColor(color, statusBarAlpha));
            } else {
                StatusBarView statusView = createStatusBarView(activity, color, statusBarAlpha);
                decorView.addView(statusView);
            }
            setRootView(activity);
        }
    }

    /**
     * 设置状态栏纯色 不加半透明效果
     *
     * @param activity 需要设置的 activity
     * @param color    状态栏颜色值
     */
    public static void setColorNoTranslucent(Activity activity, int color) {
        setColor(activity, color, 0);
    }

    /**
     * 设置状态栏颜色(5.0以下无半透明效果,不建议使用)
     *
     * @param activity 需要设置的 activity
     * @param color    状态栏颜色值
     */
    public static void setColorDiff(Activity activity, int color) {
        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.KITKAT) {
            return;
        }
        activity.getWindow().addFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
        // 生成一个状态栏大小的矩形
        ViewGroup decorView = (ViewGroup) activity.getWindow().getDecorView();
        int count = decorView.getChildCount();
        if (count > 0 && decorView.getChildAt(count - 1) instanceof StatusBarView) {
            decorView.getChildAt(count - 1).setBackgroundColor(color);
        } else {
            StatusBarView statusView = createStatusBarView(activity, color);
            decorView.addView(statusView);
        }
        setRootView(activity);
    }

    /**
     * 使状态栏半透明
     *
     * 适用于图片作为背景的界面,此时需要图片填充到状态栏
     *
     * @param activity 需要设置的activity
     */
    public static void setTranslucent(Activity activity) {
        setTranslucent(activity, DEFAULT_STATUS_BAR_ALPHA);
    }

    /**
     * 使状态栏半透明
     *
     * 适用于图片作为背景的界面,此时需要图片填充到状态栏
     *
     * @param activity       需要设置的activity
     * @param statusBarAlpha 状态栏透明度
     */
    public static void setTranslucent(Activity activity, int statusBarAlpha) {
        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.KITKAT) {
            return;
        }
        setTransparent(activity);
        addTranslucentView(activity, statusBarAlpha);
    }

    /**
     * 设置状态栏全透明
     *
     * @param activity 需要设置的activity
     */
    public static void setTransparent(Activity activity) {
        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.KITKAT) {
            return;
        }
        transparentStatusBar(activity);
        setRootView(activity);
    }

    /**
     * 使状态栏透明(5.0以上半透明效果,不建议使用)
     *
     * 适用于图片作为背景的界面,此时需要图片填充到状态栏
     *
     * @param activity 需要设置的activity
     */
    public static void setTranslucentDiff(Activity activity) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
            // 设置状态栏透明
            activity.getWindow().addFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
            setRootView(activity);
        }
    }

    /**
     * 为DrawerLayout 布局设置状态栏变色
     *
     * @param activity     需要设置的activity
     * @param drawerLayout DrawerLayout
     * @param color        状态栏颜色值
     */
    public static void setColorForDrawerLayout(Activity activity, DrawerLayout drawerLayout, int color) {
        setColorForDrawerLayout(activity, drawerLayout, color, DEFAULT_STATUS_BAR_ALPHA);
    }

    /**
     * 为DrawerLayout 布局设置状态栏颜色,纯色
     *
     * @param activity     需要设置的activity
     * @param drawerLayout DrawerLayout
     * @param color        状态栏颜色值
     */
    public static void setColorNoTranslucentForDrawerLayout(Activity activity, DrawerLayout drawerLayout, int color) {
        setColorForDrawerLayout(activity, drawerLayout, color, 0);
    }

    /**
     * 为DrawerLayout 布局设置状态栏变色
     *
     * @param activity       需要设置的activity
     * @param drawerLayout   DrawerLayout
     * @param color          状态栏颜色值
     * @param statusBarAlpha 状态栏透明度
     */
    public static void setColorForDrawerLayout(Activity activity, DrawerLayout drawerLayout, int color, int statusBarAlpha) {
        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.KITKAT) {
            return;
        }
        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(Color.TRANSPARENT);
        } else {
            activity.getWindow().addFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
        }
        // 生成一个状态栏大小的矩形
        // 添加 statusBarView 到布局中
        ViewGroup contentLayout = (ViewGroup) drawerLayout.getChildAt(0);
        if (contentLayout.getChildCount() > 0 && contentLayout.getChildAt(0) instanceof StatusBarView) {
            contentLayout.getChildAt(0).setBackgroundColor(calculateStatusColor(color, statusBarAlpha));
        } else {
            StatusBarView statusBarView = createStatusBarView(activity, color);
            contentLayout.addView(statusBarView, 0);
        }
        // 内容布局不是 LinearLayout 时,设置padding top
        if (!(contentLayout instanceof LinearLayout) && contentLayout.getChildAt(1) != null) {
            contentLayout.getChildAt(1).setPadding(0, getStatusBarHeight(activity), 0, 0);
        }
        // 设置属性
        ViewGroup drawer = (ViewGroup) drawerLayout.getChildAt(1);
        drawerLayout.setFitsSystemWindows(false);
        contentLayout.setFitsSystemWindows(false);
        contentLayout.setClipToPadding(true);
        drawer.setFitsSystemWindows(false);

        addTranslucentView(activity, statusBarAlpha);
    }

    /**
     * 为DrawerLayout 布局设置状态栏变色(5.0以下无半透明效果,不建议使用)
     *
     * @param activity     需要设置的activity
     * @param drawerLayout DrawerLayout
     * @param color        状态栏颜色值
     */
    public static void setColorForDrawerLayoutDiff(Activity activity, DrawerLayout drawerLayout, int color) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
            activity.getWindow().addFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
            // 生成一个状态栏大小的矩形
            ViewGroup contentLayout = (ViewGroup) drawerLayout.getChildAt(0);
            if (contentLayout.getChildCount() > 0 && contentLayout.getChildAt(0) instanceof StatusBarView) {
                contentLayout.getChildAt(0).setBackgroundColor(calculateStatusColor(color, DEFAULT_STATUS_BAR_ALPHA));
            } else {
                // 添加 statusBarView 到布局中
                StatusBarView statusBarView = createStatusBarView(activity, color);
                contentLayout.addView(statusBarView, 0);
            }
            // 内容布局不是 LinearLayout 时,设置padding top
            if (!(contentLayout instanceof LinearLayout) && contentLayout.getChildAt(1) != null) {
                contentLayout.getChildAt(1).setPadding(0, getStatusBarHeight(activity), 0, 0);
            }
            // 设置属性
            ViewGroup drawer = (ViewGroup) drawerLayout.getChildAt(1);
            drawerLayout.setFitsSystemWindows(false);
            contentLayout.setFitsSystemWindows(false);
            contentLayout.setClipToPadding(true);
            drawer.setFitsSystemWindows(false);
        }
    }

    /**
     * 为 DrawerLayout 布局设置状态栏透明
     *
     * @param activity     需要设置的activity
     * @param drawerLayout DrawerLayout
     */
    public static void setTranslucentForDrawerLayout(Activity activity, DrawerLayout drawerLayout) {
        setTranslucentForDrawerLayout(activity, drawerLayout, DEFAULT_STATUS_BAR_ALPHA);
    }

    /**
     * 为 DrawerLayout 布局设置状态栏透明
     *
     * @param activity     需要设置的activity
     * @param drawerLayout DrawerLayout
     */
    public static void setTranslucentForDrawerLayout(Activity activity, DrawerLayout drawerLayout, int statusBarAlpha) {
        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.KITKAT) {
            return;
        }
        setTransparentForDrawerLayout(activity, drawerLayout);
        addTranslucentView(activity, statusBarAlpha);
    }

    /**
     * 为 DrawerLayout 布局设置状态栏透明
     *
     * @param activity     需要设置的activity
     * @param drawerLayout DrawerLayout
     */
    public static void setTransparentForDrawerLayout(Activity activity, DrawerLayout drawerLayout) {
        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.KITKAT) {
            return;
        }
        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(Color.TRANSPARENT);
        } else {
            activity.getWindow().addFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
        }

        ViewGroup contentLayout = (ViewGroup) drawerLayout.getChildAt(0);
        // 内容布局不是 LinearLayout 时,设置padding top
        if (!(contentLayout instanceof LinearLayout) && contentLayout.getChildAt(1) != null) {
            contentLayout.getChildAt(1).setPadding(0, getStatusBarHeight(activity), 0, 0);
        }

        // 设置属性
        ViewGroup drawer = (ViewGroup) drawerLayout.getChildAt(1);
        drawerLayout.setFitsSystemWindows(false);
        contentLayout.setFitsSystemWindows(false);
        contentLayout.setClipToPadding(true);
        drawer.setFitsSystemWindows(false);
    }

    /**
     * 为 DrawerLayout 布局设置状态栏透明(5.0以上半透明效果,不建议使用)
     *
     * @param activity     需要设置的activity
     * @param drawerLayout DrawerLayout
     */
    public static void setTranslucentForDrawerLayoutDiff(Activity activity, DrawerLayout drawerLayout) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
            // 设置状态栏透明
            activity.getWindow().addFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
            // 设置内容布局属性
            ViewGroup contentLayout = (ViewGroup) drawerLayout.getChildAt(0);
            contentLayout.setFitsSystemWindows(true);
            contentLayout.setClipToPadding(true);
            // 设置抽屉布局属性
            ViewGroup vg = (ViewGroup) drawerLayout.getChildAt(1);
            vg.setFitsSystemWindows(false);
            // 设置 DrawerLayout 属性
            drawerLayout.setFitsSystemWindows(false);
        }
    }

    /**
     * 添加半透明矩形条
     *
     * @param activity       需要设置的 activity
     * @param statusBarAlpha 透明值
     */
    private static void addTranslucentView(Activity activity, int statusBarAlpha) {
        ViewGroup contentView = (ViewGroup) activity.findViewById(android.R.id.content);
        // 移除半透明矩形,以免叠加
        if (contentView.getChildCount() > 1) {
            contentView.getChildAt(1).setBackgroundColor(Color.argb(statusBarAlpha, 0, 0, 0));
        } else {
            contentView.addView(createTranslucentStatusBarView(activity, statusBarAlpha));
        }
    }

    /**
     * 生成一个和状态栏大小相同的彩色矩形条
     *
     * @param activity 需要设置的 activity
     * @param color    状态栏颜色值
     * @return 状态栏矩形条
     */
    private static StatusBarView createStatusBarView(Activity activity, int color) {
        // 绘制一个和状态栏一样高的矩形
        StatusBarView statusBarView = new StatusBarView(activity);
        LinearLayout.LayoutParams params =
            new LinearLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, getStatusBarHeight(activity));
        statusBarView.setLayoutParams(params);
        statusBarView.setBackgroundColor(color);
        return statusBarView;
    }

    /**
     * 生成一个和状态栏大小相同的半透明矩形条
     *
     * @param activity 需要设置的activity
     * @param color    状态栏颜色值
     * @param alpha    透明值
     * @return 状态栏矩形条
     */
    private static StatusBarView createStatusBarView(Activity activity, int color, int alpha) {
        // 绘制一个和状态栏一样高的矩形
        StatusBarView statusBarView = new StatusBarView(activity);
        LinearLayout.LayoutParams params =
            new LinearLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, getStatusBarHeight(activity));
        statusBarView.setLayoutParams(params);
        statusBarView.setBackgroundColor(calculateStatusColor(color, alpha));
        return statusBarView;
    }

    /**
     * 设置根布局参数
     */
    private static void setRootView(Activity activity) {
        ViewGroup rootView = (ViewGroup) ((ViewGroup) activity.findViewById(android.R.id.content)).getChildAt(0);
        rootView.setFitsSystemWindows(true);
        rootView.setClipToPadding(true);
    }

    /**
     * 使状态栏透明
     */
    @TargetApi(Build.VERSION_CODES.KITKAT)
    private static void transparentStatusBar(Activity activity) {
        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().addFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_NAVIGATION);
            activity.getWindow().setStatusBarColor(Color.TRANSPARENT);
        } else {
            activity.getWindow().addFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
        }
    }

    /**
     * 创建半透明矩形 View
     *
     * @param alpha 透明值
     * @return 半透明 View
     */
    private static StatusBarView createTranslucentStatusBarView(Activity activity, int alpha) {
        // 绘制一个和状态栏一样高的矩形
        StatusBarView statusBarView = new StatusBarView(activity);
        LinearLayout.LayoutParams params =
            new LinearLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, getStatusBarHeight(activity));
        statusBarView.setLayoutParams(params);
        statusBarView.setBackgroundColor(Color.argb(alpha, 0, 0, 0));
        return statusBarView;
    }

    /**
     * 获取状态栏高度
     *
     * @param context context
     * @return 状态栏高度
     */
    private static int getStatusBarHeight(Context context) {
        // 获得状态栏高度
        int resourceId = context.getResources().getIdentifier("status_bar_height", "dimen", "android");
        return context.getResources().getDimensionPixelSize(resourceId);
    }

    /**
     * 计算状态栏颜色
     *
     * @param color color值
     * @param alpha alpha值
     * @return 最终的状态栏颜色
     */
    private static int calculateStatusColor(int color, int alpha) {
        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;
    }

    /**
     * 为有 ImageView 的Activity 添加半透明状态栏
     *
     * @param activity 需要设置的Activity
     */
    private static void setTranslucentForImageView(Activity activity) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
            activity.getWindow()
                .setFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS, WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
            if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {
                addTranslucentView(activity, DEFAULT_STATUS_BAR_ALPHA);
            }
        }
    }
}