Tips

防止在当前Activity中截屏

@Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        //防止当前activity内截屏     getWindow().addFlags(WindowManager.LayoutParams.FLAG_SECURE);}

查看当前Activity和包名，方便调试

安装TopActivity.apk

wireshark抓包找不到网卡

1、命令提示符-右键-以管理员身份运行
2、输入net start npf回车，提示NetGroup Packet Filter Driver 服务已经启动成功。
3、重新打开wireshark或者刷新网卡设备即可发现网卡。

实现圆角进度对话框

效果，类似于GooglePlay进度效果：

1、创建对话框

Dialog dialog = new Dialog(this, R.style.mydialog);//R.style.mydialog为样式，用于实现圆角效果        dialog.setContentView(R.layout.dialog);        dialog.show();

2、定义样式R.style.mydialog

<style name="mydialog" parent="android:style/Theme.Dialog">        <!-- 背景透明 -->        <item name="android:windowBackground">@android:color/transparent</item>        <!-- 没有标题 -->        <item name="android:windowNoTitle">true</item>        <!-- 背景模糊 -->        <item name="android:backgroundDimEnabled">true</item>    </style>

3、定义对话框布局R.layout.dialog

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"              android:layout_width="match_parent"              android:layout_height="wrap_content"              android:background="@drawable/shape"              android:gravity="center"              android:orientation="vertical"              android:paddingBottom="10dp"              android:paddingLeft="40dp"              android:paddingRight="40dp"              android:paddingTop="10dp">    <ProgressBar        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:indeterminateDrawable="@drawable/layer_list_progress"/>    <TextView        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_marginTop="8dp"        android:text="努力加载中..."        android:textColor="#fff"        android:textSize="16sp"/></LinearLayout>//背景的shape<?xml version="1.0" encoding="utf-8"?><shape android:shape="rectangle" xmlns:android="http://schemas.android.com/apk/res/android">    <solid android:color="@android:color/darker_gray" />    <corners android:radius="10dp" /></shape>//进度条的drawable<?xml version="1.0" encoding="utf-8"?><layer-list xmlns:android="http://schemas.android.com/apk/res/android" >    <item>        <rotate            android:drawable="@drawable/spinner_big_inner"            android:fromDegrees="0"            android:pivotX="50%"            android:pivotY="50%"            android:toDegrees="720" />    </item>    <item>        <rotate            android:drawable="@drawable/spinner_big_outer"            android:fromDegrees="360"            android:pivotX="50%"            android:pivotY="50%"            android:toDegrees="0" />    </item></layer-list>

TextView设置圆形背景效果

效果如图：

private void init() {         // A Drawable with a color gradient for buttons, backgrounds, etc.        GradientDrawable gradientDrawable = new GradientDrawable();        gradientDrawable.setSize(200,200);//大小        gradientDrawable.setCornerRadius(100);//圆角半径        gradientDrawable.setColor(Color.RED);//颜色可传        ImageView imageView = (ImageView) findViewById(R.id.iv);        imageView.setBackground(gradientDrawable);    }

FragmentStatePagerAdapter Vs FragmentPagerAdapter

/**
* Implementation of {@link android.support.v4.view.PagerAdapter} that
* uses a {@link Fragment} to manage each page. This class also handles
* saving and restoring of fragment’s state.
*
*

This version of the pager is more useful when there are a large number
* of pages, working more like a list view. When pages are not visible to
* the user, their entire fragment may be destroyed, only keeping the saved
* state of that fragment. This allows the pager to hold on to much less
* memory associated with each visited page as compared to
* {@link FragmentPagerAdapter} at the cost of potentially more overhead when
* switching between pages.
*/

/**
* Implementation of {@link android.support.v4.view.PagerAdapter} that
* represents each page as a {@link Fragment} that is persistently
* kept in the fragment manager as long as the user can return to the page.
*
*

This version of the pager is best for use when there are a handful of
* typically more static fragments to be paged through, such as a set of tabs.
* The fragment of each page the user visits will be kept in memory, though its
* view hierarchy may be destroyed when not visible. This can result in using
* a significant amount of memory since fragment instances can hold on to an
* arbitrary amount of state. For larger sets of pages, consider
*{@link FragmentStatePagerAdapter}.
*/

总结：
《1》二者都是PagerAdapter的实现，用于维护ViewPager中的Ffragment
《2》FragmentStatePagerAdapter 处理Fragment状态的保存和恢复，后者只要用户还能够返回该Fragment，那么就会将其保留在Fragment Manager中。
《3》FragmentStatePagerAdapter 其机制类似于ListView，当页面不可见时，整个Fragment可能被销毁，而只保留其状态，因此内存更友好。
FragmentPagerAdapter而言，尽管View可能会被销毁，但是整个Fragment会将Fragment完全保留在内存中。
因此，前者更适合于大量的Fragment使用时；后者则更多是用于处理静态Fragment。

因此，对于Fragment的状态及生命周期不敏感时，会推荐使用前者。