Android开发实现透明通知栏

这个特性是andorid4.4支持的，最少要api19才可以使用，也就是说如果Android的机子是低于4.4，沉浸通知栏是没有效果的。下面介绍一下使用的方法，非常得简单。

 public void initSystemBar() {
         if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
             setTranslucentStatus(true);
             SystemBarTintManager tintManager = new SystemBarTintManager(this);
             tintManager.setStatusBarTintEnabled(true);
             tintManager.setStatusBarTintResource(R.color.blue);
         }
     }

     /**
      * 设置通知栏的状态
      * @param on
      */
     @SuppressLint("InlinedApi")
     private void setTranslucentStatus(boolean on) {
         Window win = this.getWindow();
         WindowManager.LayoutParams winParams = win.getAttributes();
         final int bits = WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS;
         if (on) {
             winParams.flags |= bits;
         } else {
             winParams.flags &= ~bits;
         }
         win.setAttributes(winParams);
     }

 import java.lang.reflect.Method;

 import android.annotation.SuppressLint;
 import android.annotation.TargetApi;
 import android.app.Activity;
 import android.content.Context;
 import android.content.res.Configuration;
 import android.content.res.Resources;
 import android.content.res.TypedArray;
 import android.graphics.drawable.Drawable;
 import android.os.Build;
 import android.util.DisplayMetrics;
 import android.util.TypedValue;
 import android.view.Gravity;
 import android.view.View;
 import android.view.ViewConfiguration;
 import android.view.ViewGroup;
 import android.view.Window;
 import android.view.WindowManager;
 import android.widget.FrameLayout.LayoutParams;

 /**
  * Class to manage status and navigation bar tint effects when using KitKat
  * translucent system UI modes.
  *
  */
 public class SystemBarTintManager {

     static {
         // Android allows a system property to override the presence of the navigation bar.
         // Used by the emulator.
         // See https://github.com/android/platform_frameworks_base/blob/master/policy/src/com/android/internal/policy/impl/PhoneWindowManager.java#L1076
         if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
             try {
                 Class c = Class.forName("android.os.SystemProperties");
                 Method m = c.getDeclaredMethod("get", String.class);
                 m.setAccessible(true);
                 sNavBarOverride = (String) m.invoke(null, "qemu.hw.mainkeys");
             } catch (Throwable e) {
                 sNavBarOverride = null;
             }
         }
     }

     /**
      * The default system bar tint color value.
      */
     public static final int DEFAULT_TINT_COLOR = 0x99000000;

     private static String sNavBarOverride;

     private final SystemBarConfig mConfig;
     private boolean mStatusBarAvailable;
     private boolean mNavBarAvailable;
     private boolean mStatusBarTintEnabled;
     private boolean mNavBarTintEnabled;
     private View mStatusBarTintView;
     private View mNavBarTintView;

     /**
      * Constructor. Call this in the host activity onCreate method after its
      * content view has been set. You should always create new instances when
      * the host activity is recreated.
      *
      * @param activity The host activity.
      */
     @TargetApi(19)
     public SystemBarTintManager(Activity activity) {

         Window win = activity.getWindow();
         ViewGroup decorViewGroup = (ViewGroup) win.getDecorView();

         if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
             // check theme attrs
             int[] attrs = {android.R.attr.windowTranslucentStatus,
                     android.R.attr.windowTranslucentNavigation};
             TypedArray a = activity.obtainStyledAttributes(attrs);
             try {
                 mStatusBarAvailable = a.getBoolean(0, false);
                 mNavBarAvailable = a.getBoolean(1, false);
             } finally {
                 a.recycle();
             }

             // check window flags
             WindowManager.LayoutParams winParams = win.getAttributes();
             int bits = WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS;
             if ((winParams.flags & bits) != 0) {
                 mStatusBarAvailable = true;
             }
             bits = WindowManager.LayoutParams.FLAG_TRANSLUCENT_NAVIGATION;
             if ((winParams.flags & bits) != 0) {
                 mNavBarAvailable = true;
             }
         }

         mConfig = new SystemBarConfig(activity, mStatusBarAvailable, mNavBarAvailable);
         // device might not have virtual navigation keys
         if (!mConfig.hasNavigtionBar()) {
             mNavBarAvailable = false;
         }

         if (mStatusBarAvailable) {
             setupStatusBarView(activity, decorViewGroup);
         }
         if (mNavBarAvailable) {
             setupNavBarView(activity, decorViewGroup);
         }

     }

     /**
      * Enable tinting of the system status bar.
      *
      * If the platform is running Jelly Bean or earlier, or translucent system
      * UI modes have not been enabled in either the theme or via window flags,
      * then this method does nothing.
      *
      * @param enabled True to enable tinting, false to disable it (default).
      */
     public void setStatusBarTintEnabled(boolean enabled) {
         mStatusBarTintEnabled = enabled;
         if (mStatusBarAvailable) {
             mStatusBarTintView.setVisibility(enabled ? View.VISIBLE : View.GONE);
         }
     }

     /**
      * Enable tinting of the system navigation bar.
      *
      * If the platform does not have soft navigation keys, is running Jelly Bean
      * or earlier, or translucent system UI modes have not been enabled in either
      * the theme or via window flags, then this method does nothing.
      *
      * @param enabled True to enable tinting, false to disable it (default).
      */
     public void setNavigationBarTintEnabled(boolean enabled) {
         mNavBarTintEnabled = enabled;
         if (mNavBarAvailable) {
             mNavBarTintView.setVisibility(enabled ? View.VISIBLE : View.GONE);
         }
     }

     /**
      * Apply the specified color tint to all system UI bars.
      *
      * @param color The color of the background tint.
      */
     public void setTintColor(int color) {
         setStatusBarTintColor(color);
         setNavigationBarTintColor(color);
     }

     /**
      * Apply the specified drawable or color resource to all system UI bars.
      *
      * @param res The identifier of the resource.
      */
     public void setTintResource(int res) {
         setStatusBarTintResource(res);
         setNavigationBarTintResource(res);
     }

     /**
      * Apply the specified drawable to all system UI bars.
      *
      * @param drawable The drawable to use as the background, or null to remove it.
      */
     public void setTintDrawable(Drawable drawable) {
         setStatusBarTintDrawable(drawable);
         setNavigationBarTintDrawable(drawable);
     }

     /**
      * Apply the specified alpha to all system UI bars.
      *
      * @param alpha The alpha to use
      */
     public void setTintAlpha(float alpha) {
         setStatusBarAlpha(alpha);
         setNavigationBarAlpha(alpha);
     }

     /**
      * Apply the specified color tint to the system status bar.
      *
      * @param color The color of the background tint.
      */
     public void setStatusBarTintColor(int color) {
         if (mStatusBarAvailable) {
             mStatusBarTintView.setBackgroundColor(color);
         }
     }

     /**
      * Apply the specified drawable or color resource to the system status bar.
      *
      * @param res The identifier of the resource.
      */
     public void setStatusBarTintResource(int res) {
         if (mStatusBarAvailable) {
             mStatusBarTintView.setBackgroundResource(res);
         }
     }

     /**
      * Apply the specified drawable to the system status bar.
      *
      * @param drawable The drawable to use as the background, or null to remove it.
      */
     @SuppressWarnings("deprecation")
     public void setStatusBarTintDrawable(Drawable drawable) {
         if (mStatusBarAvailable) {
             mStatusBarTintView.setBackgroundDrawable(drawable);
         }
     }

     /**
      * Apply the specified alpha to the system status bar.
      *
      * @param alpha The alpha to use
      */
     @TargetApi(11)
     public void setStatusBarAlpha(float alpha) {
         if (mStatusBarAvailable && Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
             mStatusBarTintView.setAlpha(alpha);
         }
     }

     /**
      * Apply the specified color tint to the system navigation bar.
      *
      * @param color The color of the background tint.
      */
     public void setNavigationBarTintColor(int color) {
         if (mNavBarAvailable) {
             mNavBarTintView.setBackgroundColor(color);
         }
     }

     /**
      * Apply the specified drawable or color resource to the system navigation bar.
      *
      * @param res The identifier of the resource.
      */
     public void setNavigationBarTintResource(int res) {
         if (mNavBarAvailable) {
             mNavBarTintView.setBackgroundResource(res);
         }
     }

     /**
      * Apply the specified drawable to the system navigation bar.
      *
      * @param drawable The drawable to use as the background, or null to remove it.
      */
     @SuppressWarnings("deprecation")
     public void setNavigationBarTintDrawable(Drawable drawable) {
         if (mNavBarAvailable) {
             mNavBarTintView.setBackgroundDrawable(drawable);
         }
     }

     /**
      * Apply the specified alpha to the system navigation bar.
      *
      * @param alpha The alpha to use
      */
     @TargetApi(11)
     public void setNavigationBarAlpha(float alpha) {
         if (mNavBarAvailable && Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
             mNavBarTintView.setAlpha(alpha);
         }
     }

     /**
      * Get the system bar configuration.
      *
      * @return The system bar configuration for the current device configuration.
      */
     public SystemBarConfig getConfig() {
         return mConfig;
     }

     /**
      * Is tinting enabled for the system status bar?
      *
      * @return True if enabled, False otherwise.
      */
     public boolean isStatusBarTintEnabled() {
         return mStatusBarTintEnabled;
     }

     /**
      * Is tinting enabled for the system navigation bar?
      *
      * @return True if enabled, False otherwise.
      */
     public boolean isNavBarTintEnabled() {
         return mNavBarTintEnabled;
     }

     private void setupStatusBarView(Context context, ViewGroup decorViewGroup) {
         mStatusBarTintView = new View(context);
         LayoutParams params = new LayoutParams(LayoutParams.MATCH_PARENT, mConfig.getStatusBarHeight());
         params.gravity = Gravity.TOP;
         if (mNavBarAvailable && !mConfig.isNavigationAtBottom()) {
             params.rightMargin = mConfig.getNavigationBarWidth();
         }
         mStatusBarTintView.setLayoutParams(params);
         mStatusBarTintView.setBackgroundColor(DEFAULT_TINT_COLOR);
         mStatusBarTintView.setVisibility(View.GONE);
         decorViewGroup.addView(mStatusBarTintView);
     }

     private void setupNavBarView(Context context, ViewGroup decorViewGroup) {
         mNavBarTintView = new View(context);
         LayoutParams params;
         if (mConfig.isNavigationAtBottom()) {
             params = new LayoutParams(LayoutParams.MATCH_PARENT, mConfig.getNavigationBarHeight());
             params.gravity = Gravity.BOTTOM;
         } else {
             params = new LayoutParams(mConfig.getNavigationBarWidth(), LayoutParams.MATCH_PARENT);
             params.gravity = Gravity.RIGHT;
         }
         mNavBarTintView.setLayoutParams(params);
         mNavBarTintView.setBackgroundColor(DEFAULT_TINT_COLOR);
         mNavBarTintView.setVisibility(View.GONE);
         decorViewGroup.addView(mNavBarTintView);
     }

     /**
      * Class which describes system bar sizing and other characteristics for the current
      * device configuration.
      *
      */
     public static class SystemBarConfig {

         private static final String STATUS_BAR_HEIGHT_RES_NAME = "status_bar_height";
         private static final String NAV_BAR_HEIGHT_RES_NAME = "navigation_bar_height";
         private static final String NAV_BAR_HEIGHT_LANDSCAPE_RES_NAME = "navigation_bar_height_landscape";
         private static final String NAV_BAR_WIDTH_RES_NAME = "navigation_bar_width";
         private static final String SHOW_NAV_BAR_RES_NAME = "config_showNavigationBar";

         private final boolean mTranslucentStatusBar;
         private final boolean mTranslucentNavBar;
         private final int mStatusBarHeight;
         private final int mActionBarHeight;
         private final boolean mHasNavigationBar;
         private final int mNavigationBarHeight;
         private final int mNavigationBarWidth;
         private final boolean mInPortrait;
         private final float mSmallestWidthDp;

         private SystemBarConfig(Activity activity, boolean translucentStatusBar, boolean traslucentNavBar) {
             Resources res = activity.getResources();
             mInPortrait = (res.getConfiguration().orientation == Configuration.ORIENTATION_PORTRAIT);
             mSmallestWidthDp = getSmallestWidthDp(activity);
             mStatusBarHeight = getInternalDimensionSize(res, STATUS_BAR_HEIGHT_RES_NAME);
             mActionBarHeight = getActionBarHeight(activity);
             mNavigationBarHeight = getNavigationBarHeight(activity);
             mNavigationBarWidth = getNavigationBarWidth(activity);
             mHasNavigationBar = (mNavigationBarHeight > 0);
             mTranslucentStatusBar = translucentStatusBar;
             mTranslucentNavBar = traslucentNavBar;
         }

         @TargetApi(14)
         private int getActionBarHeight(Context context) {
             int result = 0;
             if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.ICE_CREAM_SANDWICH) {
                 TypedValue tv = new TypedValue();
                 context.getTheme().resolveAttribute(android.R.attr.actionBarSize, tv, true);
                 result = TypedValue.complexToDimensionPixelSize(tv.data, context.getResources().getDisplayMetrics());
             }
             return result;
         }

         @TargetApi(14)
         private int getNavigationBarHeight(Context context) {
             Resources res = context.getResources();
             int result = 0;
             if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.ICE_CREAM_SANDWICH) {
                 if (hasNavBar(context)) {
                     String key;
                     if (mInPortrait) {
                         key = NAV_BAR_HEIGHT_RES_NAME;
                     } else {
                         key = NAV_BAR_HEIGHT_LANDSCAPE_RES_NAME;
                     }
                     return getInternalDimensionSize(res, key);
                 }
             }
             return result;
         }

         @TargetApi(14)
         private int getNavigationBarWidth(Context context) {
             Resources res = context.getResources();
             int result = 0;
             if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.ICE_CREAM_SANDWICH) {
                 if (hasNavBar(context)) {
                     return getInternalDimensionSize(res, NAV_BAR_WIDTH_RES_NAME);
                 }
             }
             return result;
         }

         @TargetApi(14)
         private boolean hasNavBar(Context context) {
             Resources res = context.getResources();
             int resourceId = res.getIdentifier(SHOW_NAV_BAR_RES_NAME, "bool", "android");
             if (resourceId != 0) {
                 boolean hasNav = res.getBoolean(resourceId);
                 // check override flag (see static block)
                 if ("1".equals(sNavBarOverride)) {
                     hasNav = false;
                 } else if ("0".equals(sNavBarOverride)) {
                     hasNav = true;
                 }
                 return hasNav;
             } else { // fallback
                 return !ViewConfiguration.get(context).hasPermanentMenuKey();
             }
         }

         private int getInternalDimensionSize(Resources res, String key) {
             int result = 0;
             int resourceId = res.getIdentifier(key, "dimen", "android");
             if (resourceId > 0) {
                 result = res.getDimensionPixelSize(resourceId);
             }
             return result;
         }

         @SuppressLint("NewApi")
         private float getSmallestWidthDp(Activity activity) {
             DisplayMetrics metrics = new DisplayMetrics();
             if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
                 activity.getWindowManager().getDefaultDisplay().getRealMetrics(metrics);
             } else {
                 // TODO this is not correct, but we don't really care pre-kitkat
                 activity.getWindowManager().getDefaultDisplay().getMetrics(metrics);
             }
             float widthDp = metrics.widthPixels / metrics.density;
             float heightDp = metrics.heightPixels / metrics.density;
             return Math.min(widthDp, heightDp);
         }

         /**
          * Should a navigation bar appear at the bottom of the screen in the current
          * device configuration? A navigation bar may appear on the right side of
          * the screen in certain configurations.
          *
          * @return True if navigation should appear at the bottom of the screen, False otherwise.
          */
         public boolean isNavigationAtBottom() {
             return (mSmallestWidthDp >= 600 || mInPortrait);
         }

         /**
          * Get the height of the system status bar.
          *
          * @return The height of the status bar (in pixels).
          */
         public int getStatusBarHeight() {
             return mStatusBarHeight;
         }

         /**
          * Get the height of the action bar.
          *
          * @return The height of the action bar (in pixels).
          */
         public int getActionBarHeight() {
             return mActionBarHeight;
         }

         /**
          * Does this device have a system navigation bar?
          *
          * @return True if this device uses soft key navigation, False otherwise.
          */
         public boolean hasNavigtionBar() {
             return mHasNavigationBar;
         }

         /**
          * Get the height of the system navigation bar.
          *
          * @return The height of the navigation bar (in pixels). If the device does not have
          * soft navigation keys, this will always return 0.
          */
         public int getNavigationBarHeight() {
             return mNavigationBarHeight;
         }

         /**
          * Get the width of the system navigation bar when it is placed vertically on the screen.
          *
          * @return The width of the navigation bar (in pixels). If the device does not have
          * soft navigation keys, this will always return 0.
          */
         public int getNavigationBarWidth() {
             return mNavigationBarWidth;
         }

         /**
          * Get the layout inset for any system UI that appears at the top of the screen.
          *
          * @param withActionBar True to include the height of the action bar, False otherwise.
          * @return The layout inset (in pixels).
          */
         public int getPixelInsetTop(boolean withActionBar) {
             return (mTranslucentStatusBar ? mStatusBarHeight : 0) + (withActionBar ? mActionBarHeight : 0);
         }

         /**
          * Get the layout inset for any system UI that appears at the bottom of the screen.
          *
          * @return The layout inset (in pixels).
          */
         public int getPixelInsetBottom() {
             if (mTranslucentNavBar && isNavigationAtBottom()) {
                 return mNavigationBarHeight;
             } else {
                 return 0;
             }
         }

         /**
          * Get the layout inset for any system UI that appears at the right of the screen.
          *
          * @return The layout inset (in pixels).
          */
         public int getPixelInsetRight() {
             if (mTranslucentNavBar && !isNavigationAtBottom()) {
                 return mNavigationBarWidth;
             } else {
                 return 0;
             }
         }

     }

在最后在布局文件中添加：android:fitsSystemWindows="true"

即可实现。