Unity3d:ngui when there is a button in the Srollview sub-object, tap cannot scroll

Using the ScrollView control in Ngui, you can add and manage subkeys through gird, which generally works normally. But if you put a button as a ScrollView subkey or a button in a subkey, you'll see that the button works, but ScrollView won't scroll when you click on the button. If you remove the Boxcollider component of the button, the ScrollView is normal.

The solution to this problem is to add the Uidrag Scroll view script to the button and everything is OK.

Unity3d:ngui when there is a button in the Srollview sub-object, tap cannot scroll