从developer.android.com:

public void finishAffinity () 在API级别16中添加

Finish this activity as well as all activities immediately below it in the current task that have the same affinity. This is typically used when an application can be launched on to another task (such as from an ACTION_VIEW of a content type it understands) and the user has used the up navigation to switch out of the current task and in to its own task. In this case, if the user has navigated down into any other activities of the second application, all of those should be removed from the original task as part of the task switch.

请注意，此结束不允许您向前一个活动交付结果，如果您试图这样做，则会抛出异常。

在我的情况下，我使用finishAffinity()函数在最后的活动，如:

finishAffinity()
startHomeActivity()

希望对大家有用。

Intent intent = new Intent(this, classObject);
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK | IntentCompat.FLAG_ACTIVITY_CLEAR_TASK);
startActivity(intent);

这将适用于所有Android版本。其中IntentCompat类添加到Android支持库。

如果您在屏幕1中登录用户，然后从那里转到其他屏幕，请使用

Intent intent = new Intent(this, Screen1.class);
intent.addFlags(FLAG_ACTIVITY_CLEAR_TOP);
startActivity(intent);

从developer.android.com:

public void finishAffinity () 在API级别16中添加

Finish this activity as well as all activities immediately below it in the current task that have the same affinity. This is typically used when an application can be launched on to another task (such as from an ACTION_VIEW of a content type it understands) and the user has used the up navigation to switch out of the current task and in to its own task. In this case, if the user has navigated down into any other activities of the second application, all of those should be removed from the original task as part of the task switch.

请注意，此结束不允许您向前一个活动交付结果，如果您试图这样做，则会抛出异常。

当用户点击登出按钮，然后写以下代码:

Intent intent = new Intent(this, LoginActivity.class);
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(intent);

并且登录后如果调用new activity，不要使用finish();