Android singleTask、startActivityForResult 冲突解决

最近项目中在A Activity 中使用startActivityForResult 去B Activity中获取一些数据，当B Activity launch mode 为 singleTask 的时候，发现一直获取不到B返回的数据，A中的 onActivityResult 方法没有被调用。查看官方文档才发现 startActivityForResult 与 onActivityResult 有冲突，如下图所示：



Note that this method should only be used with Intent protocols that are defined to return a result. In other protocols (such as

Intent.ACTION_MAIN

or

Intent.ACTION_VIEW

), you may not get the result when you expect. For example, if the activity you are launching uses the singleTask launch mode, it will not run in your task and thus
you will immediately receive a cancel result. 

解决办法：

将B的launch mode 改为singleTop，或者采取别的方法