1、使用SnapKit库重构了弹窗基类及部分弹窗视图，支持横竖屏切换换；

2、支持多个弹窗存在（详细请查看：同时显示两个弹窗的演示）；
3、升级到Swift4.2；

FWPopupView/FWPopupView.podspec

@@ -16,7 +16,7 @@ Pod::Spec.new do |s|
   #
 
   s.name         = "FWPopupView"
-  s.version      = "3.1.5"
+  s.version      = "4.0.0"
   s.summary      = "自定义弹窗"
 
   # This description is used to generate tags and improve search results.
@@ -64,7 +64,7 @@ Pod::Spec.new do |s|
   #  the deployment target. You can optionally include the target after the platform.
   #
 
-  s.swift_version  = "4.0" 
+  s.swift_version  = "4.2" 
   s.platform     = :ios
   s.platform     = :ios, "8.0"
 
@@ -131,7 +131,8 @@ Pod::Spec.new do |s|
   #  where they will only apply to your library. If you depend on other Podspecs
   #  you can include multiple dependencies to ensure it works.
 
-  # s.requires_arc = true
+  s.requires_arc = true
+  s.dependency "SnapKit"
 
   # s.xcconfig = { "HEADER_SEARCH_PATHS" => "$(SDKROOT)/usr/include/libxml2" }
   # s.dependency "JSONKit", "~> 1.4"