Android-Overview Screen

学会使用Flag对Activity设置，然后可以更好的管理Activity 栈。

With the Android 5.0 release (API level 21), multiple instances of the same activity containing different
documents may appear as tasks in the overview screen.

Using the flags of the

Intent

class
to add a task affords greater control over when and how a document gets opened or reopened in the overview screen. When you use the

<activity>

attributes
you can choose between always opening the document in a new task or reusing an existing task for the document.

Activity：意图标签和Activity属性设置

Using the Intent flag to add a task。

Using the activity attribute to add a task。

The

FLAG_ACTIVITY_NEW_DOCUMENT

flag
replaces the

FLAG_ACTIVITY_CLEAR_WHEN_TASK_RESET

flag,
which is deprecated as of Android 5.0 (API level 21).