首先定义一个主题  

    <style name="Theme.Black.NoTitleBarw" parent="@android:style/Theme.Black.NoTitleBar">
        <item name="android:statusBarColor">@android:color/transparent</item>
        <item name="android:windowDrawsSystemBarBackgrounds">true</item>
    </style>

然后在activity加入代码

 if (Build.VERSION.SDK_INT >22) {  //6.0
   Window window = getWindow();
   window.addFlags(WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS);
   window.setStatusBarColor(Color.parseColor("#34aebb"));
}else{
getWindow().setFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS, WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
}